Biochemistry

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 The maintenance of stable internal conditions in

spite of changes in the external environment is

called homeostasis.

All living organisms must maintain a stable internal

environment.

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.

Are viruses such as swine flu

and HIV 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!

Requirements to be

considered living:

Cellular organization

Homeostasis

Metabolism

Responsiveness

Reproduction

Heredity

Growth

So are viruses alive? 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.

Viruses At this point in time, viruses are still considered to be

non-living (different from dead – these things have

never been nor ever will be living). For the

purposes of this class, viruses are non-living.

This is up for change though, as the scientific

community re-defines what constitutes “living”

In the next 10 years, viruses could be considered a

living thing!!

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?

Yes, because they can reproduce

Yes, because they are composed of cells

No, because they cannot adapt to their

environment

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: Leave the dish uncovered, and place the dish in

the refrigerator

Cover the dish, and place the dish in the

refrigerator

Leave the dish uncovered, and place the dish in a

dark, room temperature cabinet

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

temperature cabinet.

What is the best definition of a

scientific theory? An explanation of how and why a natural

phenomenon behaves the way it does

A description of an invariable relationship that

exists in nature

A speculation or guess about how nature works

An unproven fact

A little 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.

Atomic Structure and the

Periodic Table Atomic number = # of

protons

In a neutrally charged atom, the # protons = # electrons

In an ion (a charged particle), the # electrons will change More electrons than protons =

negative ion

Fewer electrons than protons = positive ion

Atomic mass number = # protons + # neutrons

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?

The atomic mass of carbon is 12.

How many neutrons should carbon have?

If an element is made of atoms that have different

numbers of neutrons, then they are called isotopes.

Give it a try…fill in the table! Element Atomic # Atomic

Mass **

# Protons # Neutrons #Electrons

Carbon

Hydrogen

Oxygen

Phosphorus

Nitrogen

** Round the number for the atomic mass given in the periodic table to the

nearest WHOLE NUMBER.

There are no ions nor isotopes in this activity.

A quick word on bonding Covalent bond: a bond where two atoms share

valence electrons

Commonly seen in bonding between atoms in

biomolecules

Ionic bond: a bond where one atom completely

transfers its valence electrons to another atom

Hydrogen bond: a bond where a molecule has

slightly charged poles (making it a polar compound)

and can form slight electrostatic bonds with other

polar molecules

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 (NOTE: all names end in –ose):

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.

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

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

Biomolecule Review Name Monomer Elements

Present

Function Examples

Carbohydrate Monosaccharide C, H, O Quick energy

source

Glucose

Sucrose

Starch

Glycogen

Chitin

Lipid Glycerol

backbone, fatty

acid tails

C, H, O, P Stored energy Phospholipid

Fats

Oils

Proteins Amino Acid C, H, O, N Structure,

enzymes,

hormones

Keratin

Insulin

Lactase

Nucleic Acids Nucleotide C, H, O, N, P Genetic

information

DNA

mRNA

tRNA

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.

Hydrogen Bond: A 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 vocabulary word 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 will stick to each other, so as one water

molecule is pulled up, the other water molecules it is

“stuck” to will also be pulled up. Those water

molecules will pull up the water they are “stuck” to,

and so on.

Water molecules stick to other

polar substances Adhesion - attraction between particles of different

substances.

This also helps explain why water moves up a plant.

As water moves up the tubes of the plant (called

xylem), the water will “stick” to the walls, helping it not

fall back down due to gravity.

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!

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 (called substrates) 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 substrates

will bind to it.

Each enzyme acts only on specific substrates.

This is why SHAPE is so important.

When substrates bind to the enzyme, it changes

their structure and allows reactions to take place

using less energy.

Products

Products Substrate

Enzyme

Enzyme-Substrate Complex

Enzyme Enzyme

Active Site

Enzymes and Substrates

Competitive Inhibitors

Competitive Inhibitor (orange)

Inhibitors with Allosteric Site

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.

Which vocabulary term does this remind you of?

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

Cosmetics often contain glycerol (C3H8O3) which

has three identical functional groups. Which type of

bond holds these functional groups together?

Ionic

Covalent

Hydrogen

Sulfuric

Which of the following is used by the

body as its main quick energy

source? Lipid

Carbohydrate

Protein

Nucleic Acid

Which ratio typically describes the

Carbon:Hydrogen:Oxygen in a

carbohydrate? 1:2:1

2:6:2

4:3:1

2:1:2

Elements present in lipids

include: C,H,O

C,H,O,N

C,H,O,P

C,H,O,N,P

Building blocks of carbohydrates

are: Polysaccharides

Disaccharides

Monosaccharides

Trisaccharides

Phospholipids are found in: Cell membranes

Cell Wall

Nucleus

Ribosomes

Has names ending in the suffix

-ose protein

carbohydrates

Nucleic acids

lipids

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 shape

protein

happy

active

Enzymes are which type of

biomolecule? Carbohydrate

Protein

Lipid

Nucleic Acid

True or False: Enzymes increase

the activation energy of a reaction. True

False

True or False: Enzymes are important

because they allow reaction to proceed

at lower energies.

True

False

Enzymes are specific. enzyme

substrate

protein

carbohydrate

What is the maximum number of

covalent bonds that Carbon can make

with hydrogen?

1

2

3

4