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BIO 1 Laboratory Manual Microscope Number: Department of Life Sciences Riverside City College Fall 2019 Sashkin/Shutterstock.com NOT FOR DISTRIBUTION - FOR INSTRUCTOR USE ONLY

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Page 1: BIO 1 - websites.rcc.edu

BIO 1Laboratory Manual

Microscope Number:

Department of Life Sciences Riverside City College

Fall 2019

Sashkin/S

hutterstock.com

NOT FOR DISTRIBUTION - FOR INSTRUCTOR USE ONLY

Page 2: BIO 1 - websites.rcc.edu

Copyright © 2019 by the Department of Life Sciences, Riverside City College

Copyright © 2019 by Hayden-McNeil, LLC on illustrations provided

Photos provided by Hayden-McNeil, LLC are owned or used under license

Cover Images: Mada_Cris/Shutterstock.com; Jubal Harshaw/Shutterstock.com; dencg/

Shutterstock.com; farbled/Shutterstock.com; Likoper/Shutterstock.com

All rights reserved.

Permission in writing must be obtained from the publisher before any part of this work

may be reproduced or transmitted in any form or by any means, electronic or mechanical,

including photocopying and recording, or by any information storage or retrieval system.

Printed in the United States of America

10 9 8 7 6 5 4 3 2 1

ISBN 978-1-5339-1186-5

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iiiBIO 1 Laboratory Manual

Table of Contents

1 The Scientific Method. . . . . . . . . . . . . . . . . . . . . . . . . 1

2 The Metric System and Basic Microscopy . . . . . . . . . . . . 11

3 Biological Molecules . . . . . . . . . . . . . . . . . . . . . . . . 27

4 Introduction to Cells, Molecular Movement, and Membrane Transport . . . . . . . . . . . . . . . . . . . . . . 41

5 Respiration and Photosynthesis . . . . . . . . . . . . . . . . . . 53

6 Cell Cycle, DNA Synthesis, Mitosis and Meiosis . . . . . . . . . 63

7 Introduction to Mendelian Genetics . . . . . . . . . . . . . . . . 75

Lab Practical 1 Review Sheet. . . . . . . . . . . . . . . . . . . . 93

8 Gene Expression and DNA Technology . . . . . . . . . . . . . . 95

9 Evolution and Natural Selection . . . . . . . . . . . . . . . . . .111

10 Kingdoms Bacteria, Protista, and Fungi . . . . . . . . . . . . . .119

11 Kingdom Plantae . . . . . . . . . . . . . . . . . . . . . . . . . .143

12 Kingdom Animalia. . . . . . . . . . . . . . . . . . . . . . . . . .155

13 Ecology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .179

14 Conservation Biology . . . . . . . . . . . . . . . . . . . . . . . .189

Lab Practical 2 Final Review Sheet . . . . . . . . . . . . . . . .193

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iv BIO 1 Laboratory Manual NOT FOR DISTRIBUTION - FOR INSTRUCTOR USE ONLY

Page 5: BIO 1 - websites.rcc.edu

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EXERCISE 1The Scientific Method

The purpose of this lab is to practice being a scientist. In this lab, you will learn how scientists

approach research, and learn to develop your own research skills. This will include evaluating

criteria for a good question, evaluating hypotheses, and how to design an experiment.

The scientific method is the approach that scientists use to conduct research. There are several

steps in the scientific method. The first step is to make an observation about your surround-

ings. These observations will form the foundation of the research, so careful observation is nec-

essary. The second step is to ask a question about your observation. It is more difficult than you

might think to ask a scientific question. The question needs to be narrow in scope and testable.

The third step is to develop a hypothesis, an educated guess that is a possible answer to your

question. The hypothesis needs to be testable and falsifiable. This means that you must be able

to conduct scientific experiments to test whether your hypothesis is valid. Once you have de-

veloped your hypothesis, you must design an experiment that allows you to test that hypoth-

esis. While we do not have the time in this course to delve very far into experimental design, it

is important to identify your independent variable (the parameter of your experiment that you,

as the experimenter, will adjust) and your control (the parameter of your experiment that will

be used to compare to the treatments). These items will be critical for determining the design

of your experiment. Once your data are gathered, you will need to do statistical analysis to

compare the results of your treatments to see if they are valid. At this point, you can determine

if you will accept your hypothesis or reject it.

ACTIVITY 1

Laboratory SafetyScientific laboratories are exciting places with lots of activity and lots of people. This creates an

environment that can become dangerous if we are not aware of our surroundings. It is impor-

tant in a science lab to always be alert and aware of what is happening around you because an

emergency can arise at any moment. There are several safety measures that will help to keep

you safe in the laboratory environment, but they must be followed each and every time you

are in the lab.

1. Always wear long pants and closed-toed shoes. This is very important for avoiding chemi-

cal exposure to your skin and for protecting your feet from broken glass. We will be work-

ing with both chemicals and glassware in the lab, so these are very real risks. To be safest,

it is best to be covered up. Bare skin is much more vulnerable than covered skin, so reduc-

ing bare skin is best to improve safety. Beyond wearing these lab-appropriate items, you

should be aware that we will be using various stains in the lab. We use them to help us visu-

alize parts of cells, but they can permanently stain your clothes or skin if they contact you.

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2 EXERCISE 1 The Scientific Method

1 2. Always carry your microscope with two hands. One hand goes into the slot on the neck

of the scope and the other hand goes under the scope. Do not lift the microscope using the

stage or any other part of the scope. Our microscopes are precision equipment and must be

treated very carefully. Also, be aware that the microscopes have small feet on the bottom.

Be careful not to knock them off when sliding the scope back onto the shelf in the micro-

scope cabinets. You will be introduced to the microscope in Exercise 4.

3. Because of the nature of the research being conducted in our building, if the fire alarm goes

off you need to evacuate immediately. Follow the signs in the lab that direct you to the ap-

propriate evacuation route. Remember, you may not smell smoke. Not all emergencies that

require evacuation in a science building involve fire. Get out of the building immediately

and move to the designated rendezvous location for your class. If the alarm goes off, it

does not mean you are dismissed from class, so do not leave campus.

4. Please do not touch broken glass and do not put it in the regular trashcan. If you discover

broken glass or accidentally break something glass, please alert your lab instructor and

have them dispose of the glass safely. It needs to be put into the glass disposal area to avoid

injuring someone in the regular trash.

5. Be sure you have read and understood the directions for each experiment before attending

lab. You should read the lab exercise ahead of your scheduled lab time. Not following the

instructions can result in failed experiments, which can result in losing points on assigned

data summaries. Furthermore, not following instructions can put you or your study organ-

ism at risk, both of which are unacceptable circumstances.

6. Because of the types of experiments we do and the types of dangers present in the room, it

is important to know the types of safety equipment in the lab. There is a fire extinguisher

in case of fire, an eyewash in case you get chemicals in your eyes, and there is a chemical

shower in case you get chemicals on your skin. All of these types of safety equipment are

located near the exit to the classroom. You want to familiarize yourself with their location

in case of an emergency. Of course, this equipment is only for use in emergencies and

should never be used for any other reason.

7. Your lab instructor may ask you to take a picture of how the lab is set up when you first

enter the room. It is important to understand that you are responsible for cleanup (at your

lab bench, at the sinks, and anywhere else in the room). One way to be sure to get the room

cleaned up correctly is to refer back to your photo of how the room was set up when you

came in. Allowing phones to be out in the room is up to your lab instructor, so do not dis-

obey their instructions. However, if they allow it, taking a picture can be very helpful at

the end of lab.

As scientists, we often work in groups. Research is a collaborative effort that requires input

from many other people. As such, we will often work in teams in lab. Do not confuse teamwork

with group assignments. For each homework assignment it will be expected that you do your

own work and turn in your own assignment. While you will work in groups during lab and

discuss your outcomes, it is not appropriate to turn in someone else’s work as your own. When

scientists work together on a research project, everyone’s name is included on the paper. Be

sure you are doing your own work and not using answers obtained from your group members.

When your name is on the paper, you need to be sure you have genuinely done the work.

Additionally, it is expected that all work will be done at a college level. You should be using

correct grammar, spelling, and punctuation and writing in complete sentences. Failure to do

so can result in lost points.

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3EXERCISE 1 The Scientific Method

ACTIVITY 2

Experimental Design

Designing a Testable QuestionHow do you define the problem you wish to investigate? Every investigation begins with a

question that the scientist wants to answer. Questions are answered by scientific observations,

information gathered through previous research, or both.

Can all questions be answered scientifically? Absolutely not.

Working in pairs, or small groups, decide which of the following questions can be answered by

the scientific method. Be able to explain your reasoning!

• Are serial killers evil by nature?

• What is the cause of Mad Cow Disease?

• Why is grass green?

• What is the best recipe for chocolate chip cookies?

• Did extraterrestrials construct the Grand Canyon?

What do you think determines whether a question can be answered scientifically?

Developing a HypothesisOnce a question has been formed, the next step is to construct an appropriate hypothesis.

Hypotheses are nothing more than early explanations that attempt to answer the question

you’ve posed. A good hypothesis provides a rationale/justification along with the explanation. Remember, there is no rule governing the length of a hypothesis!

Not all hypotheses are created equal! In fact, some hypotheses are of no scientific value at all

since they are not testable.

Again, working in pairs or small groups, decide which of the following would be useful as a

scientific hypothesis. Be able to explain your reasoning!

• Plants absorb water through their leaves as well as through their roots.

• Mice require calcium for developing strong bones.

• Dogs are happy when you give them steak.

• All dogs go to heaven.

• Syphilis can be transmitted by toilet seats.

A scientific hypothesis must be both:

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4 EXERCISE 1 The Scientific Method

1 Dependent and Independent VariablesAn independent variable is what the investigator deliberately changes (e.g., concentration, tem-

perature, pH).

A dependent variable is what is measured by the investigator in order to learn the effect of

changing the independent variable.

Keep in mind that constant variables must be controlled and standardized. All variables (with

the exception of the variable being tested) must be kept constant! Think of constant variables as

factors that should be standardized for an experiment.

What are some variables that should be standardized for the following experiments?

The effect of fertilizer on the yield of tomatoes.

The effect of a drug on lowering blood pressure in a group of humans.

ControlsAll experiments require at least one control (and often more than one) in order to eliminate the

effect of a variable or else to determine the standard value. A control must be identical to the

experimental treatment except for the one variable being tested. In this way, a control is used to

“zero-out” the effects of other factors.

ACTIVITY 3Everybody is a scientist! What distinguishes science from other disciplines is that science uses

a methodical and repeatable process that generates objective evidence about the world around

us. In this activity you will learn about the scientific method and how to apply the method to

learn about nature.

Your lab instructor will demonstrate the steps of the scientific method. In the box below, make

a flowchart that indicates the steps in the scientific method.

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Page 9: BIO 1 - websites.rcc.edu

5EXERCISE 1 The Scientific Method

You and your lab partner will think of something interesting you have observed on campus

or at home. Once you have decided on a specific observation, write it below. Have your lab

instructor approve your question and hypothesis.

Observation

Question

Hypothesis

ACTIVITY 4

The Scientific Method in Action

Designing and Performing an ExperimentWhat makes a “Class Champion” thumb-wrestler? In this activity, we will explore whether the

size of the palm of the hand between the base of the pinky finger and the base of the thumb has

an effect on the overall chances of winning a thumb-wrestling match.

You will develop a hypothesis and then test this hypothesis by conducting a thumb-wrestling

tournament to determine an overall “Class Champion.”

Choose a partner and perform the following measurement in centimeters (as shown in the

drawing below) using the metric tape on your lab bench. Then have your partner perform the

same measurement on you.

Record your measurement here

©H

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Please develop a hypothesis regarding the possible outcome of this experiment.

Hypothesis:

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6 EXERCISE 1 The Scientific Method

1 Rules of Thumb Wrestling:Two players grasp hands; they touch thumbs to the opposite sides of the other person’s hand

three times, then come out wrestling. The object is to hold the other person’s thumb down for

a count of three using only your thumb. You must win 2 out of 3 “games” to win your match.

Every student plays every other student.

Analysis and ConclusionWhat have we learned from this experiment? To understand what the results of our experi-

ment are, we have to compare the results of the entire class.

Did those individuals with larger measurement win more of their matches?

Do the results support or falsify your hypothesis, or is the data inconclusive?

What is the independent variable in this experiment?

What is the dependent variable in this experiment?

List the constant variables in this experiment.

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Page 11: BIO 1 - websites.rcc.edu

7EXERCISE 1 The Scientific Method

Table 1. Record of wins and losses in thumb wrestling matches.

Opponent Game Wins Game LossesI Won the

Match (Y/N)

1.

2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

12.

13.

14.

15.

ACTIVITY 5

Dissecting MicroscopeDissecting scopes are used to investigate the surface of samples. Rather than pass light through

a sample as the compound microscopes do, dissecting scopes shine light on the surface of the

sample. This will allow you to see unique characteristics of the surface of plants, animals, or

other samples. The dissecting scopes used in this lab contain an internal light source, so they

only need to be plugged in and turned on in order to work. To use the dissecting scope, just

place your sample under the lens. Looking through the eyepiece, adjust the focus until the

sample is clearly visible to you. Because you are looking at the surface of a sample, you may

have to alter the focus depending on the topography of the sample.

To practice with the dissecting scope, you should look around campus for samples (or you

may be provided with specimens). Look for leaves that are bumpy, hairy, or textured. Look

for insects that move slowly or have expired. Look for flowers, stems, roots, or rocks. Look for

anything that has an interesting surface: your hand, coins, keys, and others. You will not be

disappointed when you view that surface under the dissecting scope.

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8 EXERCISE 1 The Scientific Method

1

Stage plate

Zoom control

knob

Focusing

knob

Stand

©Hayden-McNeil, LLC

Eye piece

Diopter

adjustment

knob

Body clamping

knob

Microscope body

(contains lens)

ON/OFF

switch

Brightness

control dial

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9EXERCISE 1 The Scientific Method

Worksheet Name

Section

Date

Staple here

1The Scientific Method

This worksheet is to be completed while reading Exercise 1 and is due when you next have lab. You are expected to do your own work. You do not have to type your answers, but please write legibly.

1. List the first three steps of the scientific method in order.

a.

b.

c.

2. Which of the questions below can be answered scientifically? (Circle the letter of all correct

answers.)

a. How far can a kangaroo rat jump?

b. Do skunks dislike squirrels?

c. How much water is necessary to keep grass green?

d. Are people who don’t like spicy food physically weak or just weak in character?

3. A good hypothesis includes which of the following? (Circle the letter of all correct an-

swers.)

a. Testable elements

b. Data analysis

c. Explanation

d. Calculation

4. Which variable is the one that is adjusted by the experimenter? (Circle the letter of all cor-

rect answers.)

a. Dependent variable

b. Independent variable

c. Constant variable

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10 EXERCISE 1 The Scientific Method

1 5. Of the following, which are required for personal safety in lab? (Circle the letter of all cor-

rect answers.)

a. Long pants or a long skirt that covers the ankles

b. Goggles

c. Hat or hood

d. Closed-toed shoes

e. Snake gaiters

f. Waterproof boots

g. Lab coat

6. What do you do if the fire alarm goes off but you don’t smell smoke? (Circle the letter of

all correct answers.)

a. Stay where you are. Some chuckle-head probably pulled the alarm to avoid a quiz.

b. Get out of the building and move to the designated rendezvous location.

c. Wait for directions from your lab instructor or other faculty or staff.

d. Go home immediately.

7. True or False? Because students will often work in teams during lab, it is appropriate for a

student to copy homework answers from their team members.

8. The morning before a Biology 1 midterm, half of the students in a class were given plain

water for breakfast while the other half were given an energy drink. The average exam

scores of the two groups were compared to see if the type of drink has an effect on the

students’ grades.

a. What is the dependent variable in this study?

b. What is the independent variable in this study?

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11

EXERCISE 2The Metric System and Basic Microscopy

The purpose of this lab is to learn about the metric system and basic microscopy. You will learn

the metric system, including how to take measurements using metric units. Additionally, you

will learn about microscopes and microscope care and maintenance. You will be asked to mea-

sure various objects, including cells, in the metric system. This lab may require you to walk

around campus, so please dress accordingly for the weather.

ACTIVITY 1

Scientific NotationIn an effort to avoid confusion and to maintain the highest levels of accuracy, scientists utilize

scientific notation when reporting large or small values. This method prevents readers from

having to count decimal places or zeros. Numbers represented in scientific notation have one

digit before the decimal point. All remaining significant digits follow the decimal point. This

number is multiplied by the appropriate factor of 10 to represent the original number. If the

original number is smaller than 1, the exponent on the factor of 10 will be negative. If the origi-

nal number is larger than 1, the exponent on the factor of 10 will be positive.

For example, to represent the number 20045 in scientific notation:

• Insert the decimal point after the first non-zero whole number digit of the original number:

2.0045

• Determine the exponent on the power of 10 that is appropriate by counting the number of

spaces the decimal point has moved. In this case the decimal point has moved 4 spaces.

The exponent is positive because the original number is much larger than 1.

• Represent the number in the following form: 2.0045 # 104

To represent the number 0.03984 in scientific notation:

• Insert the decimal point after the first non-zero whole number digit of the original number:

3.984

• Determine the exponent on the power of 10 that is appropriate by counting the number

of spaces the decimal point has moved: in this case the decimal point has moved 2 spaces.

The exponent is negative because the original number is smaller than 1.

• Represent the number in the following form: 3.984 # 10−2

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12 EXERCISE 2 The Metric System and Basic Microscopy

2 Exponents: 1 = 100 1.00 = 100

10 = 101 0.10 = 10−1

100 = 102 0.01 = 10−2

1,000 = 103 0.001 = 10−3

10,000 = 104 0.0001 = 10−4

100,000 = 105 0.00001 = 10−5

1,000 # 1,000 = 103 # 103 = 106 or 1,000,000

1,000,000 ' 1,000 = 106 ' 103 = 103 or 1,000

1/1,000 # 1/1,000 = 10−3 # 10−3 = 10−6 or 1/1,000,000 or 0.000001

Try This!Write the following numbers in scientific notation:

324567 =

0.004567 =

23456000 =

ACTIVITY 2

The Metric System and Metric ConversionsAlthough the metric system is used in nearly all other countries in the world, the United States

continues to use English units such as the pound for mass, the mile for distance, and the gal-

lon for volume. In the sciences, the metric system is used for all measurements including dis-

tances, volumes, masses, and temperature. In this lab, you will become familiar with the metric

system and converting from one metric measure to another.

The Units of the Metric SystemThe metric system is based on basic units. For length the base unit is the meter, for volume the

base unit is the liter, and for mass the base unit is the gram. For example, if we used the base

unit of length in the metric system, a trip from Riverside to downtown Los Angeles would be

roughly 80,000 meters. Wow! That is a large number. Is there a way to simplify this number?

The metric system has many prefixes to help simplify very large or very small values. By add-

ing a prefix before the word “meter,” we can alter the outward appearance of the value. The

most common prefixes that will be used in this course are kilo-, deci-, centi-, and milli-.

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13EXERCISE 2 The Metric System and Basic Microscopy

deci

centi

milli

micro

large

small

Kilo

If you move from the base unit up toward the prefix kilo- and place “kilo” in front of the word

meter, you are describing a distance that is composed of many meters: a kilometer. If you

move towards the prefix micro, you are describing a measurement that is much smaller than a

meter: a micrometer. How are these prefixes related to each other?

K Base d c m nμ

To understand how the prefixes are related to each other, let’s try an example. In the box

marked “Base Unit” insert the word meter.

First, let’s look at values smaller than the meter. In every meter, there are 10 decimeters. In one

decimeter, there are 10 centimeters. In one centimeter there are 10 millimeters. In one millime-

ter, there are 1,000 micrometers. See how the prefix is added to the base unit “meter”? What

would we do if we were measuring in grams?

K Base d c m nμ

Now, let’s look at the values larger than the meter. In order to have one kilometer, we would

need 1,000 meters!

Common Metric PrefixesUNIT EXAMPLE

(k) kilo = thousand—1 kilometer has 1,000 meters

(d) deci = 1/10 of the base unit—1 meter has 10 decimeters

(c) centi = 1/100 of the base unit—1 meter has 100 centimeters

(m) milli = 1/1,000 of the base unit—1 meter has 1,000 millimeters

(μ) micro = 1/1,000,000 of the base unit—1 meter has 1,000,000 micrometers

(n) nano = 1/1,000,000,000 of the base unit—1 meter has 1,000,000,000 nanometers

Try This!

1.68 m = cm

0.057 kg = g

250 ml = μl

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14 EXERCISE 2 The Metric System and Basic Microscopy

2 ACTIVITY 3

Determination of LengthBeing able to use a metric ruler is very important in scientific study. All measurements of

length will be made using metric units, but the type of unit used will vary depending on the

object being measured. In this lab, we will use centimeters and millimeters most commonly.

To familiarize ourselves with these units, we will practice using blocks. Obtain two blocks and

measure the longest length of the block. Record your measurements in the table below.

Length of Block

Determination of MassThe mass of an object is another consideration for scientific studies. In biology, often the mass

of a small object such as a seed or insect wing is needed. Precise measurement requires some-

thing more accurate than the bathroom scale! In the scientific laboratory a balance is used for

precise measurements. For this laboratory project, significant accuracy can be obtained using

the electronic balance. Accuracy for this balance is to 0.01 g. Instructions for the use of the bal-

ance will be given in the laboratory.

Using the electronic balance, weigh two blocks. Record the mass for each block in the table below.

Mass of Block

Determining Volume of LiquidsDuring many procedures, scientists and technicians often must accurately transfer a given

amount of solution. In the laboratory, a graduated cylinder is used. A graduated cylinder is a

glass or plastic cylinder with graduations for measuring liquids.

Using the graduated cylinder, you will notice that liquids cling to the sides, creating a U-shaped

appearance to the top of the fluid column. This U-shaped meniscus results from the cohesive

and adhesive properties of liquids, particularly those containing water, and the glass or plastic

of the container. To read the volume of liquid in a graduated cylinder, the value is taken at the

bottom of the meniscus.

3

2

To measure liquids in a

graduated cylinder,

read the lowest liquid

level (the bottom of the

meniscus).

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15EXERCISE 2 The Metric System and Basic Microscopy

Beakers and graduated cylinders are used in the laboratory to measure small amounts of liq-

uid. When measuring a liquid in a graduated cylinder remember to look at the meniscus when

determining the volume of the liquid.

Next, you will use the graduated cylinders at your lab station to measure the following liquid

volumes: 3 ml, 5.5 ml, and 7.8 ml. Practice first with the blue liquid provided at your lab sta-

tion. Once you feel confident with the blue liquid, try tap water.

Now try using a larger graduated cylinder. Try measuring the following liquid volumes: 23 ml,

18 ml, 38 ml, and 42 ml. Notice that the graduations on different sizes of graduated cylinders

represent different volumes of liquid. In some cases each graduation is a milliliter, in other

cases it may only be 1/10th of a milliliter, or it may even be 5 milliliters. Be sure you are mea-

suring correctly!

Next, place an arrow at the 4.8 ml mark on the syringe shown below.

©Hayden-McNeil, LLC

12345678910

Temperature MeasurementsIn the sciences, a thermometer is used to measure the temperature of liquids. Although we

may be used to looking at temperature in Fahrenheit, scientists use Celsius for temperature

measurements.

Using the thermometer provided, measure the temperature of the following in Celsius:

Temperature in Celsius

Room Temperature

Tap Water

Ice Water

Surface of Your Skin

ACTIVITY 4

Basic MicroscopySince the human eye is unable to distinguish objects smaller than 0.1 mm, observation of cells

is dependent upon the use of the microscope. The role of the microscope is to provide both

magnification of an object as well as resolution, which is the ability to distinguish between

two adjacent objects. It is this quality of resolution which provides contrast and the ability to

distinguish detail in materials being observed.

Several types of microscopes are used in biological observation and differ on the basis of the

type of energy source and lens system. One microscope that you will use in today’s laboratory

and in subsequent labs is the light microscope: the most commonly used in biological observa-

tion. Because the light used to illuminate specimens is focused through two sets of glass lenses,

this microscope is commonly called the compound light microscope. The compound light mi-

croscope is limited to 1,000#–2,000# magnifications and a resolving power of 0.2 micrometers.

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16 EXERCISE 2 The Metric System and Basic Microscopy

2 The electron microscope uses a beam of electrons as the energy source. Resolution with an

electron microscope provides 0.002 to 0.005 micrometers and magnifications up to 500,000#.

In transmission electron microscopy, electrons are focused by electromagnetic coils. Electrons

travel through the specimen at different rates giving a high resolution, one-dimensional pic-

ture of the cell. In scanning electron microscopy, electrons bounce off the surface of the speci-

men giving a three-dimensional image of the cell surface.

These are scanning electron microscope images of the surface of a common soil insect com-

monly known as the springtail because the insect uses the tail to “spring” from place to place.

These particular insects are barely visible with the naked eye. The image below is the tail with

several scale-like structures and the image to the right is a scale in detail. The magnification of

these images is located below the pictures.

15,000# 25,000#

Contrast the scanning electron images with images from the transmission electron microscope.

You can do this by visiting http://www.cellsalive.com

Components of the Light MicroscopeIn order to fully benefit from the tools the compound light microscope provides, it is important

to know the names of microscope components and how they work. First, it is important to

know how to carry and set up the microscope. Always carry the microscope with two hands: one hand holding the microscope by the arm and one hand supporting the underside of the scope. Once you set the scope on your lab bench, plug the scope into the electrical outlet, and

flip the switch to turn on the light source. The light source shines from the bottom of the scope

upwards toward the stage of the microscope. The stage is a platform where microscope slides

are placed for viewing. Slides are held in place with clips so that they will not move during

viewing. The light travels towards the stage through the iris diaphragm, which has a small

lever that allows you to regulate the amount of light traveling through your specimen to get

the best contrast of light and dark. The image of the specimen passes through the objective lens attached to the revolving nosepiece. The image can be brought into sharper focus using

first the coarse adjustment and then the fine adjustment. Finally the image of the object passes

through the ocular lens, which has a magnification of 10#. The microscopes in Biology 1 have

two ocular lenses, so they are called binocular scopes.

It is important to make sure that the lenses stay clean. Avoid touching the lenses. If the lens

requires cleaning, make sure to ask your instructor to show you how to clean the lens with lens paper only. Other materials scratch the delicate lenses.

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17EXERCISE 2 The Metric System and Basic Microscopy

Below is a diagram of a compound light microscope similar to the one you will use in Biology 1.

Oculars

Revolvingnosepiece

Objectivelenses

Scanning power (4X)

High power (40X)

Low power (10X)

Platformstage

Light

Base

Y axis

X axis

Mechanicalstage

Fine focus

Fineadjustment

Condenseraperture diaphragm

Coarseadjustment

Arm

ON/OFFswitch

Brightnesscontrol dial

©Hayden-McNeil, LLC

Focusing the Light MicroscopeAs discussed, the microscopes you use will have three objective lenses: a 4# scanning lens, a

10# low power lens, and a 40# high power lens. The objective lens magnifies the specimen by

the number on the lens; for example, the scanning lens magnifies objects four times. Always

begin to observe your slide with the 4# lens. If the object is out of focus, use the coarse adjust-ment to bring the object into focus. The coarse adjustment moves the stage either closer or

farther from the objective lens to bring objects into focus. Because the stage moves so quickly,

never use the coarse adjustment at 40#! (You may damage the objective lens.) If you want to

bring the image into sharp focus, use the fine adjustment. Using the fine adjustment is almost

always necessary at 40#.

Once the object is in focus and you desire a higher magnification for more detail, rotate the

nosepiece so the 10# objective is over the object. Again, use the coarse adjustment and fine ad-

justment to bring the object into sharp focus. You may also find that at a higher magnification,

more light is needed to illuminate the object. Finally, to see the most detail, rotate the nosepiece

so the 40# objective is over the object. Use only the fine adjustment to bring the image into

sharp focus.

When using the microscope, it is important to always keep in mind the magnification of the

image. Magnification is determined by multiplying the magnification of the objective lens by

the magnification of the ocular lens. For example, if the objective lens in use is 10# and the

ocular lens is 10#, the total magnification of the object is 100# because 10 # 10 = 100.

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18 EXERCISE 2 The Metric System and Basic Microscopy

2 As you progress from lower (scanning lens) to higher powers of magnification, note the re-

lationship of the working distance: the space between the top of the slide and the end of the

objective lens. The higher power lenses decrease the working distance while low power lenses

allow for a larger working distance.

When changing objective lenses notice the effect on the size of the field of view. The field

of view is the area of the microscope slide that can be seen at one time. As the magnification

increases, what happens to the field of view? Finally, the degree of brightness of the field

changes as magnification changes.

ACTIVITY 5

Microscope Image OrientationLook at the letter “e” on the slide before you put it on the stage of your microscope. Is it right

side up or upside down? Now observe the slide of the letter “e” at 4#. What happens to the

orientation of the letter when it is viewed through the microscope?

What happens to the orientation of the letter when it is viewed through the microscope?

When you move the slide to your right, in which direction does the image move in the field of view on the microscope?

Try to move the image down in the field of view. Which way did you have to move the slide?

Draw what you see when you look at the letter “e” on scanning power.

Size and Brightness of Field of ViewWith the same slide in place, progressively move from 4# to 40#. Note the working distance

between the objective lens and the slide at each magnification.

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19EXERCISE 2 The Metric System and Basic Microscopy

What happens to the size of the field of view and its brightness?

Do you need to increase or decrease the amount of light passing through the specimen at higher powers of magnification?

If you know the diameter of the field of view at each magnification, it is possible to estimate

the size of the objects in the field. To measure the diameter of the field of view, place a translu-

cent ruler on top of a blank glass slide and place both on the microscope stage as if they were

a prepared slide. Place the slide and ruler on the scope so that the light passing through the

diaphragm in the center of the stage illuminates the metric side of the ruler. Using the 4# objec-

tive lens, look through the microscope and focus on the ruler. Place the millimeter marks on the

ruler in such a position that they line up across the very center of the circle, or field of view, as

shown in the figure that follows:

Using the ruler as your guide, estimate the diameter of the field of view in millimeters at the

scanning (4#) power. Record your values in the following table. Note that there is a conversion

from the millimeter value you obtained to the more commonly used microscopic measure-

ment, micrometer (μm).

Lens Magnification mm in Field of View μm in Field of View

Scanning

Try These!On the basis of your measurements, what is the approximate size of the letter “e”?

What would be the size of an object (in mm) that occupies 25% of the size of a field of view that is 3.2 mm in diameter?

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20 EXERCISE 2 The Metric System and Basic Microscopy

2 Human Cheek Epithelial CellsNow, you are going to look at your own cells!

You will make a fresh wet mount of your cheek epithelial cells for microscopic observation! To

do this, gently scrape the lining of your cheek with a clean toothpick. Carefully wipe the end

of the toothpick on a slide. Before adding a coverslip, add one drop of methylene blue to the

cheek cell smear. Look at the cells at low power first and then increase the magnification so

you can identify the nucleus, cytoplasm, and the outer limits of the cell at the cell membrane.

Some other organelles may be visible as tiny spots in the cytoplasm. You may also see tiny

specks outside of the cells that may be bacteria which are normal inhabitants of the mouth.

Draw a few of your cheek cells below!

Total magnification

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21EXERCISE 2 The Metric System and Basic Microscopy

ACTIVITY 6

Metric Scavenger Hunt (if time permits)Using your knowledge of the metric system, you will need to work in groups of up to 4 stu-

dents to measure the items listed in the table below. Hopefully, these measurements will help

give you a practical reference for the types of metric measurements we will use frequently

during the semester.

Table 2.1. Measurements collected on the metric scavenger hunt.

Object Measurement

Length

Cell phone

Pen

Coin

Mass

Cell phone

Pen

House key

Volume

Pen

Coin

House key

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22 EXERCISE 2 The Metric System and Basic Microscopy

2

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23EXERCISE 2 The Metric System and Basic Microscopy

Worksheet Name

Section

Date

Staple here

2The Metric System and Basic Microscopy

1. For which of the following microscopes were you provided operational instructions?

(Circle the letter of all correct answers.)

a. Scanning electron microscope

b. Transmission electron microscope

c. Light microscope

2. How many hands should you use to carry a microscope? (Circle the letter of all correct

answers.)

a. I lift weights. I’m strong. No biggie.

b. One under the base and one in the slot on the arm.

c. Get help from a lab partner so that you don’t risk dropping it.

d. The more the merrier.

3. Where are the slides placed on the microscope for viewing?

4. Which lenses are attached to the revolving nosepiece and can be adjusted to achieve the

desired magnification? (Circle the letter of all correct answers.)

a. Ocular lens

b. Objective lens

5. Which adjustment knob do you use when using the 40# lens? (Circle the letter of all correct

answers.)

a. Fine adjustment knob

b. Coarse adjustment knob

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24 EXERCISE 2 The Metric System and Basic Microscopy

2 6. To determine the magnification of the object, what do you multiply?

#

7. In scientific notation, how many non-zero digits are acceptable before the decimal point?

8. In scientific notation, if the number you are representing is larger than 1, is the exponent on

the factor of ten positive or negative?

Practice Problems9. Write the following numbers in scientific notation.

a. 3,500 g =

b. 24,000 ml =

c. 1,313,000 nl =

d. 400,000 m =

e. 354,000,000 ml =

f. 0.00093 kg =

g. 0.00000045 dm =

h. 45,987 μl =

i. 0.0037 cg =

10. Write the numbers represented by scientific notation.

a. 6.87 # 105 km =

b. 4.5 # 104 cl =

c. 2.1 # 10−3 dg =

d. 3.5 # 10−2 m =

e. 9.1 # 104 μl =

f. 6.77 # 101 dm =

g. 4.5 # 10−5 kg =

h. 2.0 # 102 μl =

i. 9.9 # 10−2 dm =

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25EXERCISE 2 The Metric System and Basic Microscopy

11. Complete the following problems. Please show your work for all conversion problems.

a. 2.3 cm to mm

b. 8.73 kg to g

c. 54 L to ml

d. 14 km to m

e. 90.8 dm to mm

f. 76 μl to ml

g. 16.2 g to mg

h. 74 mg to g

i. 451 μl to ml

j. 25 dg to mg

k. 2.2 mm to μm

12. Hepatitis B virus (HBV) is approximately 50 nm. How many mm would that be?

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26 EXERCISE 2 The Metric System and Basic Microscopy

2

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27

EXERCISE 3

Biological Molecules

The purpose of this lab is to learn the major types of biological molecules. For each group of

biological molecules, you will be introduced to the general characteristics, the general struc-

ture, and the function of each group of molecules in living organisms. You will build models of

the biological molecules using molecular models. Additionally, you will test for the presence

of these molecules in different food/beverage items.

ACTIVITY 1

A Review of Chemical BondingElements are made up of which contain two particles in the nucleus (called

(+) and (0)) and (-) that orbit around the

. Atoms can combine to form . Each molecule is held together

by .

One type of bond that holds molecules together is the bond where electrons are

permanently given away or taken to form ions. These ions are held in the bond with electro-

negative charge. An example of a molecule with this type of bonding is .

Another type of bond that holds molecules together is the bond where elec-

trons are shared. If the electrons spend equal time around each atom it is called a

bond. An example of a molecule with this type of bonding is . If the electrons are

pulled toward one atom more of the time, it is called a bond. An example of a

molecule with this type of bonding is .

ACTIVITY 2

Introduction to Biological MoleculesThis lab focuses on the four groups of biological molecules:

Carbohydrates

Lipids

Proteins

Nucleic Acids

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28 EXERCISE 3 Biological Molecules

3 Constructing Biological MoleculesMany of the important biological molecules consist of carbon and hydrogen atoms. Most of the

time, biological molecules have functional groups. Functional groups are groups of atoms that

change the characteristics of a molecule. For example, if a hydroxyl group is added to a mol-

ecule, the molecule will become more polar. Below are four biologically important functional

groups. Please memorize their names, structure, and examples of where each can be found.

Functional Group

Hydroxyl

Carboxyl

Amine

Phosphate

Example

glucose

fatty acid

amino acids

nucleotide

OH

NH

H

C OH

O

P O

O

O

O

Structural Formulas and Molecular FormulasToday we will be examining both structural formulas and molecular formulas. A structural

formula gives the orientation of the atoms relative to each other in space. The molecular for-

mula represents the types of atoms found in the molecule and the number of each type of

atom. For example, the molecular formula for glucose is C6H

12O

6 but the structural formula is

diagrammed below.

O

CH2OH

OH

OH H

H

H

H

OH

H

OH

Glucose

What Do You Think?Is water an organic molecule? Why or why not?

What type of bonding exists between atoms of the water molecule?

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29EXERCISE 3 Biological Molecules

How many atoms can bind with hydrogen? With oxygen? With carbon?

Why do you think life is based upon carbon?

Which functional group is the most polar? Why?

Building a Water MoleculeUsing the molecular sets, you and your lab partner will build your first molecule: water. In the

molecular sets, carbon atoms are black, oxygen atoms are red, and hydrogen atoms are white.

Bonds are represented with plastic white tubing. As you build your water molecule, please

answer the following questions.

What elements make up water?

What is the molecular formula of water? What is a molecular formula?

What does the subscript number 2 following the H represent?

How many molecules of water are represented by the formula H2O?

After building your water molecule, draw the structural formula of water here:

What do the lines between H and O represent?

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30 EXERCISE 3 Biological Molecules

3 ACTIVITY 3

Carbohydrates

Building a CarbohydrateCarbohydrates are most often used for energy by living organisms and may be used for struc-

ture. The cell walls of plants, fungi, and bacteria contain the carbohydrates cellulose, chitin,

and peptidoglycan, respectively. The monomer of a carbohydrate can be a five or six carbon

sugar called a monosaccharide. These are usually found in nature with the carbon atoms linked

together in a ring as shown below. Each carbon is numbered according to the order it is found

in the ring.

C

C

C C

O

C C

1

23

4

5

6

Glucose ring structures have two forms: alpha and beta. Look at the diagrams below. If the

hydroxyl group on carbon 1 is in the same direction as the hydroxyl group on carbon 4, the

glucose is in alpha form. If these hydroxyls point in opposite directions you have made the

beta form.

O

CH2OH

OH

OH H

H

H

H

OH

H

HO

alpha glucose

O

CH2OH

OH

OH H

H

H

OH

H

H

HO

beta glucose

Although these structural differences appear slight, they create important functional differ-

ences. Alpha glucose molecules form long chains called starches which can be easily digested

by animals. Beta glucose molecules form polymers of cellulose which make up the cell walls of

plants and most animals cannot digest them.

A disaccharide is formed when two molecules of sugar bond together. In order for these two

monomers to come together, a condensation reaction must occur. During condensation, mol-

ecules are bonded together by removal of a hydrogen atom from one monomer and a hydroxyl

group is removed from the other monomer to form water. To break the bond between mono-

mers, water is added back in a process called hydrolysis.

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31EXERCISE 3 Biological Molecules

O

CH OH

OH

OH H

H

H

H

H

OH

H

HO

glucose

O

CH OH

OH

OH H

H

H

H

H

OH

HO

H

galactose

C

C

C C

C

CH OH

OH

OH H

H

H

H H

HOH

fructose

C

C C

CC

CC

C

C O

C OH

MonosaccharidesExamine the structural formulas of the three monosaccharides glucose, fructose, and galactose.

How many atoms of carbon are there in each molecule of glucose? In fructose? In galactose?

Write the molecular formula for glucose, fructose, and galactose.

Molecules of monosaccharides may have the same molecular formula but differ in their three-

dimensional structure. This is called isomerism.

Can you define isomerism in your own words here?

Build two alpha glucose molecules. Using your models, link the two alpha glucose monomers

together using a condensation reaction.

Maltose

1

23

4

5

6

1

23

4

5

6

H

OH

H OH

HHO H

H

O

CH2OH

H

OOH

OH

H OH

H

H

CH2OH

H

O

You have now formed maltose—two alpha glucose monomers.

Now link all of the glucose molecules from your lab bench together. Once you have one poly-

mer per lab bench, link the polymers together to form a short starch chain. Notice how much

larger starch is than the individual glucose molecules.

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32 EXERCISE 3 Biological Molecules

3 A Sugar Taste TestHave you ever wondered why a certain sweetener is used in foods while another is not? Which

type of sugar is the sweetest? In this activity you will taste three different sugars and three ar-

tificial sweeteners and rank them on the basis of sweetness—the sweetest will rank as number

one and the least sweet will rank as number six. Follow the instructions of your lab instructor

carefully.

Ranking Comments?

Glucose

Fructose

Sucrose

Sweet and Low

Equal

Splenda

ACTIVITY 4

Lipids

Building Lipid MoleculesLipids contain the same elements as carbohydrates but with fewer oxygen atoms. Lipids are

excellent energy sources in cells and are also used for insulation, vitamin synthesis, and as

water repellant for fur and feathers. There is not a true monomer for lipids. Today we will ex-

amine triglycerides and fatty acids.

Triglycerides are formed from one molecule of glycerol and three fatty acids. What elements

are present in glycerol? The three fatty acids are added to glycerol using dehydration synthesis.

The fatty acid can be made of just a few carbon atoms linked together in a chain as in butyric

acid or with many carbons linked together, as in lauric acid.

What is the ratio of carbon to hydrogen in these acids?

What is the difference between saturated and unsaturated fatty acids?

What functional group is found in every fatty acid?

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33EXERCISE 3 Biological Molecules

OH

OH

H

H C

H

H

CC

OHH C

OH

H

H C

O H

H

C

H

H

C

H

H

C

H

H

C

H

H

C

H

H

C

H

H

C

H

H

C

H

H

C

H

H

C

H

H

C

H

H

C

H

H

C H

H2O

glycerol fatty acid

ACTIVITY 5

Proteins

Protein MoleculesProteins are made from long chains of amino acids. Amino acids have a carboxyl group on one

end and an amine group on the other end. The generalized form of an amino acid is below:

amino acid

H

RH OH

N C

OH

C

There are twenty different amino acids found in plants and animals. A diagram of all twenty

amino acids can be found at the end of this lab.

The simplest amino acid is glycine. What is the molecular formula of this molecule?

How is alanine different from glycine?

Amino acids are linked to make polypeptides using condensation reactions.

What Do You Think?Why are proteins called polypeptides?

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34 EXERCISE 3 Biological Molecules

3 What elements are always present in amino acids?

What functional groups are always present in amino acids?

EnzymesEnzymes are proteins that catalyze the reactions of life. A basic understanding of how these

molecules work is essential to an understanding of biology.

All organisms use enzymes as catalysts to increase the rate of a chemical reaction without in-

creasing the temperature needed for the reaction. For each reaction in the cell, there is at least

one specific enzyme facilitating the reaction.

Enzymes are proteins that have a specific shape that accommodates the molecule they are

acting on called a substrate. The enzyme is not used or changed in the reaction, but races off

from one substrate to another substrate molecule of the same kind, changing as many as 50,000

substrate molecules each minute. Since there are thousands of biochemical reactions necessary

in the life of a cell, there are also thousands of different enzymes.

Enzyme EnzymeProductSubstrate

+ +

Catalase is an oxidative enzyme which catalyzes the reduction of hydrogen peroxide to pro-

duce water and oxygen. This is a common reaction in metabolism.

©Hayden-McNeil, LLC

Catalase

O2

2 H2O2

2 H2O2

CatalaseCatalase

2 H2O2 H2O

+Catalase Catalase-H2O2

complex2 H2O2 + +Catalase 2 H2O O2

You will now conduct an experiment to investigate enzyme function. You will test the enzyme

catalase that converts hydrogen peroxide (H2O

2) into water and oxygen. The source of the cata-

lase for this experiment will be potatoes. You will be testing the effect of elevated temperature

and low pH on enzyme function. Additionally, you will test the effect of increasing the quan-

tity of catalase.

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35EXERCISE 3 Biological Molecules

Obtain four clean, dry test tubes. Label the test tubes 1 through 4 with a wax pencil. Obtain

a potato core long enough to be cut into four pieces, each 1 cm in length. If your core is not

long enough, take a second core (with the same borer). Remove any skin and rinse each core

clean. Place one core into the beaker at the instruction station. This core will be cooked in the

microwave for two minutes. Finely chop the second core into small pieces, being careful not

to lose any. Place the third core into the beaker of acid located on your lab bench for at least 10

minutes. Be careful! Always handle the acid-soaked potato core with forceps because the acid

can burn your skin. Leave the fourth potato core unaltered.

Assemble four test tubes as follows:

Tube 1: 4 ml H2O

2 + unaltered potato core

Tube 2: 4 ml H2O

2 + microwaved potato core

Tube 3: 4 ml H2O

2 + chopped potato core

Tube 4: 4 ml H2O

2 + acid-soaked potato core

The liquid will begin to bubble as soon as the potato core is added. Mark the highest point the

bubbles reach on the side of each test tube using a wax pencil. Measure the distance between

the top of the liquid to the max-bubble line. Record your data in Table 3.1.

Measure the sample from the

top of the liquid line to the top

of the bubbles.

Table 3.1. Amount of bubbles produced when H2O

2 is exposed to catalase under differing

conditions.

Tube Number Potato Core Height of Bubbles (cm)

1 Unaltered

2 Microwaved

3 Chopped

4 Acid-soaked

Which treatment resulted in the greatest amount of bubbles? Why?

Which treatment produced the least amount of bubbles? Why?

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36 EXERCISE 3 Biological Molecules

3 How did lowering the pH affect the reaction? Why?

ACTIVITY 6

Nucleic Acids

NucleotidesNucleotides are important building blocks of nucleic acids (DNA and RNA), some coenzymes,

and ATP. All nucleotides are composed of a nitrogenous base, pentose sugar, and a phosphate group.

DNA, deoxyribonucleic acid, is composed of nucleotides containing one of four nitrogenous

bases: adenine, cytosine, thymine, and guanine. RNA, ribonucleic acid, does not contain thy-

mine. Instead, RNA contains the nitrogenous base uracil.

Of the nitrogenous bases in nucleic acids, three are classified as pyrimidines and two are clas-

sified as purines. The pyrimidines have a single ring structure and include cytosine, thymine,

and uracil. The purines have a double ring structure and include adenine and guanine. In the

double-helix form, DNA always has a purine nucleotide bound to a pyrimidine nucleotide by

hydrogen bonds. As a result, the helix has a uniform diameter (2 nm).

Besides the differences in nitrogenous bases, the pentose sugar differs in DNA and RNA. RNA

contains the pentose sugar ribose while DNA contains the pentose sugar deoxyribose.

When one phosphate group is added to AMP (adenosine monophosphate), adenosine diphos-

phate (ADP) is formed. When the next phosphate group is added, adenosine triphosphate

(ATP) is formed. Structural formulas of these molecules are shown below.

ATP is the energy currency of the cell. When the phosphate group is removed from ATP to

make ADP, a tremendous amount of energy is released and the cell can use this energy to do

work.

N

H

H

HH

HNC

N

N

N CC

C

C

H

OHOH

CH2OHO

OH

O

OH

O

OH

O

OPOPOP

ATPADP

AMP

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37EXERCISE 3 Biological Molecules

Deoxyribose

HOCH2

H

H

HH H

O OH

OH

Uracil

N

N

O

HH

OH

H

HN

H

H

H

NC

N

N

N C

O

CC

C

HH

Guanine (G)

N

H

H

H

HH

HNC

N

N

N CC

C

C

H

Adenine (A)

HH

ON

N

C

H

H

NC

C

C

H

Cytosine (C)

H3C H

O

O

NC

H

NC

C

C

H

Thymine (T)

CH3

N

H

CytosineThymine GuanineAdenine

N

N

N

N

N H

H

H

N

N

NN

N

N

N H

H

O

O

ON

NH

H

O

What Do You Think?What are nucleotides composed of?

What are three molecules composed of nucleotides?

What are three differences between DNA and RNA?

Why is the pentose sugar in DNA called deoxyribose?

Which nucleotides are considered purines? Which are considered pyrimidines?

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38 EXERCISE 3 Biological Molecules

3 ACTIVITY 7

Testing for Biological Molecules (if time permits)You will now test a variety of unknown products to determine which biological molecules they

contain. Using snack food and beverages you brought to lab (or those provided by your lab

instructor), you will test for the presence of glucose, starch, and protein.

Testing for ProteinPut food item into blender with 50 ml of water. Blend the food item until it is very smooth. Dip

a Combistix strip into the beaker containing the food item slurry. Rinse or wipe the residue off

the strip. Compare the color on the strip to the color chart provided with the strip to estimate

the amount of protein in the food item. Record your results in Table 3.2.

Testing for StarchUsing the same slurry, pour 3 ml of slurry into a test tube. Add several drops of iodine to

the test tube. If starch is present, the iodine will stain the starch dark blue/black. If the solu-

tion does not become very dark blue/black, there is no starch present. Record your results in

Table 3.2.

Testing for GlucoseUsing the slurry prepared for the protein test, pour 3 ml of slurry into a test tube. Add 2 drops

of Benedict’s solution. Place the test tube into a hot water bath for 15–20 minutes. If the solu-

tion becomes a yellow-orange color, there is glucose present. If the solution does not change in

color, there is no glucose present. It is important to dispose of the material in a Benedict’s test

properly. It cannot go down the drain. Please dispose of your Benedict’s test material by pour-

ing it into the flask marked “Benedict’s Waste.”

Table 3.2. Composition of food items brought to lab.

Food Item Protein Test Starch Test Glucose Test

NOT FOR DISTRIBUTION - FOR INSTRUCTOR USE ONLY

Page 43: BIO 1 - websites.rcc.edu

39EXERCISE 3 Biological Molecules

Amino Acid Structures

©Hayden-McNeil, LLC

Aspartic acid

(Asp)

I pH = 3.0

NH2

CH2CH

OH

O

C

HO

O

C

NH2

CH2CH

CH3

CH3

CH

HO

O

C

NH2

NH

CH2CH2

CH2

CH

CH3

CH CH2 CH3

HO

O

C

CH

HO

O

C

NH2

CH

CH3

CH3

CH

HO

O

C

NH2

CH3CH

HO

O

C

NH2

HCH

HO

O

C

NH2

CH2CH

OHHO

OO

CCH2C

NH2

CH2CH

NH2HO

OO

CCH2C

NH2

CH2CH

HO

O

CH2 CH2 CH2 NH2C

NH2

NH2

NH

CH2CH

HO

O

CH2 CH2 NH CC

NH2

CH2CH

NH2HO

OO

CC

NH2

CH2CH

CHHO

CH

CH

CHO

C CHC

NH2

CH2CH

HO

O

SHC

NH2

CH2CH

HO

O

CH2 CH3SC

NH2

CH2CH

HO

O

OHC

Glutamic acid

(Glu)

I pH = 3.2

Cysteine

(Cys)

I pH = 5.0

Asparagine

(Asn)

I pH = 5.4

Phenylalanine

(Phe)

I pH = 5.5

Glutamine

(Gln)

I pH = 5.7

Serine

(Ser)

I pH = 5.7

Tyrosine

(Tyr)

I pH = 5.7

Methionine

(Met)

I pH = 5.8

Tryptophan

(Trp)

I pH = 5.9

Alanine

(Ala)

I pH = 6.0

Glycine

(Gly)

I pH = 6.0

Leucine

(Leu)

I pH = 6.0

Valine

(Val)

I pH = 6.0

Isoleucine

(Ilu)

I pH = 6.1

Proline

(Pro)

I pH = 6.3

Threonine

(Thr)

I pH = 6.5

Histidine

(His)

I pH = 7.6

Lysine

(Lys)

I pH = 9.8

Arginine

(Arg)

I pH = 10.8

NH2

CH2CH

CHHO

CH

CH

CHO

C OHCC

NH2

CH2CH

CHHO

CHC CHO

C

N

C CH

HC

C

H

NH2

CH

OH

CH CH3

NH2

CH CH2

HO

O

C

HN

CHN

CH

C

HO

O

C

NOT FOR DISTRIBUTION - FOR INSTRUCTOR USE ONLY

Page 44: BIO 1 - websites.rcc.edu

40 EXERCISE 3 Biological Molecules

3

PE

RIO

DIC

TA

BLE

OF T

HE

ELE

ME

NT

SH

1.00

8Hydrogen

1 Li

6.94

Lithium

3

Na

22.9

9Sodium

11 K39

.10

Potassium

19 Rb

85.4

7Rubidium

37 Cs

132.

91Cesium

55 Fr

Francium

87

B10

.81

Boron5 Al

26.9

8Aluminum

13 Ga

69.7

2Gallium

31 In11

4.82

Indium

49 Tl

204.

38Thallium

81 Nh

Nihonium

113

C 12.0

1Carbon

6 Si

28.0

9Silicon

14 Ge

72.6

3Germanium

32 Sn

118.

71Tin

50 Pb

207.

2Lead82

Flerovium

114

N14

.01

Nitrogen

7 P30

.97

Phosphorus

15 As

74.9

2Arsenic

33 Sb

121.

76Antimony

51 Bi

208.

98Bismuth

83 Mc

Moscovium

115

O 16.0

0Oxygen

8 S32

.06

Sulfur

16 Se

78.9

7Selenium

34 Te

127.

60Tellurium

52 Po

Polonium

84

Liverm

orium

116

F19

.00

Fluorine

9 Cl

35.4

5Chlorine

17

79.9

0Bromine

35 I12

6.90

Iodine

53 At

Astatine

85 TsTennessine

117

Ne

20.1

8Neon

10He

4.00

Helium

2 Ar

39.9

5Argon

18 Kr

83.8

0Krypton

36 Xe 131.

29Xenon

54 Rn

Radon

86 Og

Oganesson

118

Be

9.01

Beryllium

4

Mg

24.3

1Magnesium

12 Ca

40.0

8Calcium

20 Sr

87.6

2Strontium

38 Ba

137.

33Barium

56 Ra

Radium

88

Sc

44.9

6Scandium

21 Y88

.91

Yttrium

39

57–7

1

89–1

03

Ti

47.8

7Titanium

22 Zr

91.2

2Zirconium

40 Hf

178.

49Hafnium

72

Rutherfordium

104

V50

.94

Vanadium

23 Nb

92.9

1Niobium

41 Ta

180.

95Tantalum

73

Dubnium

105

Cr

52.0

0Chrom

ium

24 Mo

95.9

5Molybdenum

42 W18

3.84

Tungsten

74

Seaborgium

106

Mn

54.9

4Manganese

25 Tc

Technetium

43 Re

186.

21Rhenium

75

Bohrium

107

Fe

55.8

5Iron26 Ru

101.

07Ruthenium

44 Os

190.

23Osm

ium

76

Hassium

108

Co

58.9

3Cobalt

27 Rh

102.

91Rhodium

45 Ir19

2.22

Iridium

77

Meitnerium

109

Ni

58.6

9Nickel

28 Pd

106.

42Palladium

46 Pt

195.

08Platinum

78

Darmstadtium

110

Cu

63.5

5Copper

29 Ag

107.

87Silver

47 Au

196.

97Gold

79

Roentgenium

111

Zn

65.3

8Zinc30

La

138.

91Lanthanum

57

Ce

140.

12Cerium

58

Pr

140.

91Praseodymium

59

Nd

144.

24Neodymium

60

Pm

Promethium

61

Sm

150.

36Sam

arium

62

Eu

151.

96Europium

63

Gd

157.

25Gadolinium

64

Tb

158.

93Terbium

65

Dy

162.

50Dysprosium

66

Ho

164.

93Holmium

67

Er

167.

26Erbium

68

Tm

168.

93Thulium

69

Yb

173.

05Ytterbium

70

Lu

174.

97Lutetium

71

Ac

Actinium

89

Th

232.

04Thorium

90

Pa

231.

04Protactinium

91

U23

8.03

Uranium

92

Np

Neptunium

93

Pu

Plutonium

94

Am

Americium

95

Cm

Curium

96

Bk

Berkelium

97

Cf

Californium

98

Es

Einsteinium

99

Fm

Ferm

ium

100

Md

Mendelevium

101

No

Nobelium

102

Lr

Lawrencium

103

Cd

112.

41Cadmium

48 Hg

Br

200.

59Mercury

80

Copernicium

112

1 IA

GR

OU

P

PERIOD

2 IIA3 IIIB

4 IVB

5 VB

6 VIB

7V

IIB8

9V

IIIB

1011 IB

12 IIB13 III

A14 IV

A15 VA

16 VIA

17 VIIA

18 VIII

A

1 2 3 4 5 6 7

So

lid

Liquid

Gas

Sta

te a

t st

and

ard

tem

per

atu

rean

d p

ress

ure

(0 °

C a

nd 1

atm

):A

tom

ic n

umb

er

Key

:

Ele

men

t sy

mb

olE

lem

ent

nam

eS

tand

ard

ato

mic

wei

ght

Na

22.9

9Sodium

11

FlLv

Rf

Db

Sg

Bh

Hs

Mt

Ds

Rg

RRCn

Unknown

(No

dat

a gi

ven

for

elem

ents

w

ithou

t st

able

nuc

lides

.)

ALKA

LIM

ETAL

S

NON

-MET

ALS

METALLOIDS

ALKALINE EARTH METALS

TRA

NSI

TIO

N M

ETA

LS

HALO

GENS

P-BL

OCK

MET

ALS

NOBLE GASES

LANTHANOIDS ACTINOIDS

RARE EARTH METALS

Not

es: “

Cae

sium

” an

d “

alum

iniu

m”

are

the

inte

rnat

iona

lly r

ecog

nize

d s

pel

lings

for

“ces

ium

” an

d “

alum

inum

.” A

n at

omic

wei

ght

(rela

tive

atom

ic m

ass)

of a

n el

emen

t fro

m a

sp

ecifi

ed s

ourc

e is

the

ratio

of t

he a

vera

ge m

ass

per

ato

m o

f the

ele

men

t to

1/12

of t

he m

ass

of a

n at

om o

f 12C

(IU

PA

C).

Sou

rces

: IU

PA

C p

erio

dic

tab

le 2

8 N

ovem

ber

201

6; P

ure

and

Ap

plie

d C

hem

istr

y 88

, No.

3 (2

016)

.

REV 8/2017 © Hayden-McNeil, LLC

NOT FOR DISTRIBUTION - FOR INSTRUCTOR USE ONLY