Science Skills

Bellringer Name various ways in which scientific observations

can be made.

The Nature of Science What is the GOAL of science?

It is to help us understand the natural world and

improve people’s lives.

Thinking like a scientist can help you solve problems

and think critically about your world.

Scientific Thought Scientific thought involves making observations,

using evidence to draw conclusions, being

skeptical about ideas, and being open to change

when new discoveries are made.

What does it mean to be skeptical?

A person questions the validity of accepted ideas.

The Scientific Method Most scientific investigations begin with observations

that lead to questions.

How are some ways that we OBSERVE the world

around us?

Our senses, particularly sight!

After a scientist observes something, often times a

question is asked. What is happening?

Once this question is asked, a HYPOTHESIS is

generated.

What is a hypothesis?

A hypothesis is a possible explanation of what you

have just observed and questioned.

This is not just a guess, but must be based on

scientific fact and is testable!

Exit Slip Answer on half sheet, 1//4th sheet, full sheet!!

1. Most often, what comes before a hypothesis?

Tests and Experiments A test or experiment must be done to determine if

the hypothesis is correct.

Write answer at top of note

page! Which of the following shows the first three steps of

the scientific method in there correct order?

A. hypothesis, observation, test

B. test, observation, hypothesis

C. observation, test, hypothesis

D. observation, hypothesis, test

Controlled Experiments A CONTROL GROUP serves as a standard of

comparison because the group receives no

experimental treatment.

EXPERIMENTAL GROUPS are identical to the

control group except for one factor, or variable.

The single factor that scientists change in an

experiment is called the independent variable.

Factors that may change in response to the

independent variable are called dependent

variables.

Analyzing the results of an

experiment The results of experiments and tests may support a

hypothesis or prove that a hypothesis is not true.

Drawing Conclusions Conclusions can be made after analysis of tests or

experiments.

These conclusions provide information for the

scientist to determine what action is to be taken next.

Scientific Theories Ultimate achievements in science!

When related hypotheses are well supported and

explain a great amount of data, these hypotheses

may be put together to form a THEORY!

A theory is a general explanation for a broad range

of data.

It’s NOT “just a theory”

A scientist found that the results of an experiment did not support her hypothesis. If she is following proper scientific procedure, what should she do next?

A. Discard those results and repeat the experiment

B. Accept the hypothesis and exclude data that does not fit

C. Reject the hypothesis and assume it is incorrect

D. Create a new hypothesis and a new experiment to test it

Which of the following shows the steps of the

scientific method in the correct order?

A. Hypothesis, test, observation, analysis,

conclusion

B. Observation, hypothesis, test, analysis,

conclusion

C. Conclusion, test, hypothesis, observation,

analysis

D. Test, hypothesis, conclusion, observation,

analysis

Which of the following is NOT a

step in the scientific method? A. Hypothesis

B. Conclusion

C. Observation

D. Reading

Which of the following test groups receives

NO experimental treatment? A. Control

B. Experimental

How many variables can be tested in an

experimental group?

A. 1

B. 2

C. 3

D. 4

Scientific Measurements In science, we use the metric system without

exception.

What are some units used in the metric system?

cm, m, mm, grams, L, mL etc.

Conversions-> dimensional analysis

Very important

Dimensional Analysis

How many m are in 43 cm? Hint: (1 m =

100 cm)

A. 43 m

B. .043 m

C. .43 m

D. 430 m

How many mL are in 6.2453 L?

Hint: (1000 mL = 1 L) A. 6245.3 mL

B. 62453 mL

C. .62453 mL

D. 6.2453 mL

Chan wants to determine how much

mass of fungus growing on a nutrient

agar plate changes over an eight hour

period. What is the most appropriate

unit of measure for him to use?

A. millimeter

B. kilogram

C. kilometer

D. milligram

Omid is spending the semester in England, where

the road signs are in km. If he drives from his

school for 6 miles, how many km will he have

traveled?***1 km = .62 miles*** A. 3.73

B. 4.00

C. 9.66

D. 11.00

A homeowner needs to find the surface area

of her pond in order to apply the correct

amount of herbicide. What unit of measure

would be most proper?

A. Cubic meter

B. Cubic millimeter

C. Square meter

D. Square millimeter

Up to this point… Why study science

Scientific Method

Theories

Metric Measurements

Dimensional Analysis

Much more to come!...

Microscopes When people think of scientific tools, one of the first

tools that come to mind is the microscope.

Microscopes are devices that produce magnified

images of structures that are too small to see with

the unaided eye.

The Light Microscope The most commonly used microscope is the light

microscope.

Light microscopes produce clear images of objects.

Up to 1000 X

These microscopes allow light to pass through the

specimen and use two lenses to form an image.

Very tiny organisms and even cells can be viewed

under the light microscope.

The light microscope

continued… Chemical stains can show specific structures in the

cell.

When using a light microscope, always start with the

lowest power objective.

To calculate the TOTAL MAGNIFICATION achieved

when using a particular objective, multiply the power

of the eyepiece by the power of the objective used.

For Example: eyepiece=10X Objective=40X

10 X 40 = 400X magnification.

List as many things as you can

that organisms DO…What are

the characteristics of life???

What is Biology? We have talked about science (in general) and discussed

why it is important to your life, but what exactly is Biology????

Biology is the study of life.

There are many branches of biology. What are some that you can think of? Biochemistry

Cell biology

Ecology

Microbiology

Botany

Zoology

Physiology

The study of life All organisms share certain properties.

Cellular organization

Homeostasis

Metabolism

Responsiveness

Reproduction

Heredity

Growth

All organisms do these things at some point during their life.

Cellular Organization A cell is a highly organized, tiny structure that is

enclosed in a thin covering called a membrane.

The cell is the basic structure of all living things.

Homeostasis All living organisms must maintain a stable internal

environment.

The maintenance of stable internal conditions in

spite of changes in the external environment is

called homeostasis.

Metabolism Metabolism is the sum of all of the chemical

reactions carried out in an organism.

What provides the energy for life on earth?

The sun

Responsiveness Plants and animals must be responsive to their

environment to cope with changes that occur.

The natural world is very difficult and dangerous.

Organisms must be willing to respond to changes

that occur.

Reproduction Because no organism lives forever, reproduction is

an essential part of life.

The goal of all organisms is to reproduce!

Those organisms that have the ability to survive and

reproduce avoid extinction.

Heredity When an organism reproduces it passes on its own

traits to its offspring.

Heredity is the reason that children tend to look

similar to their parents.

Growth All living organisms grow.

Some grow for only a short period of time, but other

organisms grow for thousands of years.

The Cell Theory and Viruses! Are viruses such as swine flu and AIDES living

things??

Cell theory– All living things are made up of cells.

Cells are the basic unit of all life. Each cell has a

specific job. All cells come from existing cells!

So, are viruses alive: NO!!!!!!!!!

A Virus is not made of cells, SO they are not living

organisms!

Viruses require other cells (like YOURS) for survival.

After learning about viruses in Biology class, Sam decides to

have his cat vaccinated against feline leukemia virus.

According to cell theory, are viruses, such as feline

leukemia, considered living things?

A. Yes, because they can reproduce

B. Yes, because they are composed of cells

C. No, because they cannot adapt to their

environment

D. No, because they are not composed of cells

Ethan wants to determine whether temperature affects the rate at which mold

grows on bread. He puts one piece of bread inside a covered petri dish in the

refrigerator. To determine whether temperature affects the growth of mold, Ethan

should place another piece of bread into a petri dish:

A. Leave the dish uncovered, and place the dish in

the refrigerator

B. Cover the dish, and place the dish in the

refrigerator

C. Leave the dish uncovered, and place the dish in a

dark, room temperature cabinet

D. Cover the dish, and place the dish in a dark, room

temperature cabinet.

What is the best definition of a

scientific theory? A. An explanation of how and why a natural

phenomenon behaves the way it does

B. A description of an inviriable relationship that

exists in nature

C. A speculation or guess about how nature works

D. An unproven fact

The Chemistry of Life! The parts of a cell are made up of large molecules

called biomolecules.

The basic units of most biomolecules contain atoms

of CARBON.

Carbon has 4 valence electrons so they can bond

covalently.

Carbon atoms in these chains and rings can connect

with other atoms of other elements to form the basic

unit of most biomolecules.

Carbohydrates Carbohydrates are molecules made of sugar.

A sugar contains Carbon (C), Hydrogen (H), and Oxygen (O) in a ratio of 1:2:1.

Examples of sugars:

Glucose

Sucrose

Fructose

Two sugars can be linked together to form a disaccharide.

Cells use carbohydrates for sources of energy, structural material, and cellular identification.

Monosaccharide (simple sugar)

Disaccharide (this is table sugar)

Carbohydrates as an Energy

Supply Plants store the sun’s energy for future use by

making glucose and converting it to starch.

Animals break down glucose from food to produce

energy. Stored as glycogen.

Lipids Lipids are another class of biomolecules which

include fats, phospholipids.

Lipids also provide energy!

Glycerol backbone with fatty acid tails

Made of C, H, O, and P in phospholipids.

Cosmetics often contain glycerol (C3H8O3) which

has three identical functional groups. Which type of

bond holds these functional groups together?

A. Ionic

B. Covalent

C. Hydrogen

D. Sulfuric

Which of the following is used by the

body as its main quick energy

source? A. Lipid

B. Carbohydrate

C. Protein

D. Nucleic Acid

Which ratio typically describes the

Carbon:Hydrogen:Oxygen in a

carbohydrate? A. 1:2:1

B. 2:6:2

C. 4:3:1

D. 2:1:2

Elements present in lipids

include: A. C,H,O

B. C,H,O,N

C. C,H,O,P

D. C,H,O,N,P

Building blocks of carbohydrates

are: A. Polysaccharides

B. Disaccharides

C. Monosaccharides

D. Trisaccharides

[Default]

[MC Any]

[MC All]

Phospholipids are found in: A. Cell membranes

B. Cell Wall

C. Nucleus

D. Ribosomes

Has names ending in the suffix

-ose A. protein

B. carbohydrates

C. Nucleic acids

D. lipids

Proteins Proteins are made up of amino acids.

Proteins are twisted and folded into shapes that

determine what the protein does.

Elements Present: C,H,O,N

Proteins are extremely important!

DNA codes for proteins

Which line indicates a reaction

where an enzyme is NOT present? A. Line A

B. Line B

Which point on the line indicates

the activation Energy? A. A

B. B

C. C

D. D

Substrate attachment occurs at

the site A. shape

B. protein

C. happy

D. active

Enzymes are which type of

biomolecule? A. Carbohydrate

B. Protein

C. Lipid

D. Nucleic Acid

True or False: Enzymes increase

the activation energy of a reaction. A. True

B. False

[Default]

[MC Any]

[MC All]

True or False: Enzymes are important

because they allow reaction to proceed

at lower energies.

A. True

B. False

[Default]

[MC Any]

[MC All]

Enzymes are specific. A. enzyme

B. substratre

C. protein

D. carbohydrate

What is the maximum number of

covalent bonds that Carbon can make

with hydrogen?

A. 1

B. 2

C. 3

D. 4

Nucleic Acids A nucleic acid is a long chain of nucleotide units

Elements present: C,H,O,N, P

When we link NUCLEOTIDES together we form

nucleic acids.

DNA is made of Nucleic Acids

Water and Solutions Water has many unique properties

Most of the unique properties of water result

because water molecules form hydrogen bonds with

each other.

There is partial charge within the water molecule

causing attraction to other water molecules.

Ice Floats When water freezes, hydrogen bonds lock water

molecules into a crystal structure that has empty

space.

This structure makes water less dense as a solid

than as a liquid.

Water Absorbs and Retains

Heat Hydrogen bonds are constantly breaking and

reforming between molecules.

Because of this water can absorb a large amount of

heat without changing temperature.

This property of water can also help organisms

maintain a constant internal temperature.

What does this remind you of?

Water Molecules Stick to Each

Other Hydrogen bonds hold water molecules together.

Cohesion- the attraction of particles of the same

substance.

This is why water can move up a plant.

Water molecules stick to other

polar substances Attraction between particles of different substances

is called adhesion.

This also helps explain why water moves up a plant.

Biological Reactions Living things carry out many chemical reactions that

help maintain a stable internal environment.

More energy is required to DRIVE these reaction

than the body can provide. The body is just too cold.

These reactions would not occur without ENZYMES!

(I love enzymes)

Enzymes Enzymes ARE PROTEINS!

An enzyme is a molecule that increases that rate of

a biochemical reaction.

By assisting in necessary biochemical reactions,

enzymes help organisms maintain homeostasis.

Without enzymes you would DIE!

Enzymes Continued Enzymes FIT with reactants like a lock fits a key.

This is why shape is so important.

Enzymes Continued Each enzyme has an active site where the substrate

binds.

The shape of the site determines which reactants or

substrates will bind to it.

Each enzyme acts only on specific substrates.

This is why SHAPE is so important.

When reactants bind to the enzyme, it changes their

structure and allows reactions to take place using

less energy.

A little more Chemistry! Matter: anything that has mass and takes up space.

To understand how living things work and interact,

you must first understand the structure of matter.

Matter is made of small particles called atoms.

Atom: the smallest unit of matter that cannot be

broken down any smaller.

Atomic Structure Atoms are made of THREE types of particles

Protons (+) positive charge

Electrons (-) negative charge

Neutrons have no charge

Protons and Neutrons make up the core (nucleus) of

the atom, while electrons move around the nucleus

in the electron cloud.

Elements Elements: substance made up of atoms.

For example each atom of the element carbon has 6

protons (+).

To be balanced, how many electrons (-) should

carbon have?

Neutrons?

If an element is made of atoms that have different

numbers of neutrons, then they are called isotopes.

Determining Protons, Neutrons,

and Electrons Look at the periodic table….

Hydrogen?

Nitrogen?

Oxygen?

Chlorine?

Acids and Bases Acids: compounds that form extra hydronium ions (H+)

when dissolved in water. Your stomach uses a solution of hydrochloric acid, HCl, to

digest food.

Bases: compounds that form extra hydroxide ions (OH-) when dissolved in water. Example: Sodium Hydroxide (NaOH)

pH and buffers

pH is a measure of how acidic or basic a solution is.

pH of pure water is 7

Below 7 is acidic

Above 7 is basic

The pH of human blood must remain stable.

What does this remind you of?

Buffers are substances that reacts to prevent pH changes in a solution.