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BIOMOLECULES

Ms. Bosse – Fall 2015

• Biology is the

study of the living

world.

Bio = life

Biology

Major Molecules of Life

◦Macromolecules –

giant molecules

found in living cells;

made from

thousands of

smaller molecules.

• Macromolecules are formed

by a process known as

polymerization, in which large

compounds are built by

joining smaller ones together.

The smaller units are called

monomers. Monomers join

together to form polymers.

◦Dehydration Synthesis is the process of removing a H2O molecule from

two reactants (monomers) to create

bonds thus forming a single, larger

molecule (polymer).

◦Hydrolysis is the process of

adding a H2O to a reactant

to break bonds forming two

separate molecules.

Four categories of biomolecules:

◦Carbohydrates

◦ Lipids

◦ Proteins

◦Nucleic Acids

Biomolecules have 4 common characteristics:1. All are carbon based….meaning they all contain carbon.

2. They are formed from just a few elements which join together

to form small molecules which join together, or bond, to form

large molecules.

Common Characteristics

3. Each kind of biomolecule is built from a

single type of building block.

EXAMPLES:

Carbohydrate - monosaccharide

Lipid - fatty acid

Protein - amino acid

Nucleic Acid - nucleotide

◦ 4. The last common characteristic of all

biomolecules is that their form determines their

function. That means that their shape

determines how they will behave and how

they will react with other molecules.

Common Characteristics

Carbohydrates

• Living things use carbohydrates

as their main source of energy

• Plants use carbohydrates for

structural purposes

• Carbohydrates are sugars and

starches

Carbohydrates

◦ They are composed of carbon, hydrogen and oxygen .

◦ The carbon forms a carbon ring.

◦Single sugar molecules are

called monosaccharide. These

are the monomers.

◦Monosaccharides include

glucose, fructose and

galactose.

NOTE: Glucose and fructose join

to form sucrose in the above

picture. Glucose and fructose are

monomers. Once they join, a

molecule of water is lost, and the

polymer, sucrose is formed.

glucose fructose sucrose

A monosaccharide –

-Mono = “one or single”

-saccharide = “sugar”

building block of all

carbohydrates

Main energy molecules

of living things

=

•Large macromolecules formed from

many monosaccharides are known as

polysaccharides; they are made in a

process called polymerization.

Polysaccharides are the polymer.

Poly = “many”

saccharide = “sugar”

macro = “very large”

Polysaccharides are many monosaccharides bonded together.

POLYSACCHARIDE

◦Polysaccharides include:

starches ,cellulose and

glycogen.

Starch

Starch is a carbohydrate that is used in

food storage of plants. Potatoes, pasta

and rice are rich in starch. Starches are

very valuable because they provide a

quick form of energy for the body.

Glycogen

◦Glycogen is used for food storage in

animals. It is stored in the liver and

muscles of animals.

Cellulose

◦Cellulose is used for structural support

in plants…..mainly the stems and

leaves. It is found in the cell walls of

plants.

Monosaccharide(ONE simple sugar)

Polysaccharide(Many simple sugars)

LIPIDS

◦ Lipids are composed of carbon,

hydrogen and oxygen. However the

carbon is arranged in a chain…not a

ring or circle like the carbohydrate.

Lipids

o Fats, oils and waxes

o Do not dissolve in water (insoluble)

o Long term storage of energy….not

quick energy like carbohydrates

Lipids are formed from a glycerol

molecule and several fatty acids

Lipids are found in:

◦ Cell membranes

◦ Vitamins

◦ Enzymes

◦ Hormones

LIPIDS

Examples; fats, phospholipids,

steroids

◦Saturated fats join carbon to

carbon with a single bond.

◦Unsaturated fats join at least

one carbon atom to another

carbon atom with a double

bond

◦Polyunsaturated fats have more

than one carbon to carbon

double bond.

◦ FATS:

◦ Saturated: solid at room temp. (butter)

◦Unsaturated: oils at room temp. (olive oil)

◦ PHOSPHOLIPIDS:

◦ found in the cell membrane

◦ STEROIDS:

◦estrogen, testosterone, cholesterol (hormones)

NUCLEIC ACIDS

◦ Nucleic Acids are composed of carbon, hydrogen, oxygen,

nitrogen and phosphorus.

◦ Nucleic acids involve genetic materials, like DNA and RNA. DNA

is the blueprint of life because it contains the instructions on how

to make proteins in the body.

Nucleic Acids◦ Nucleic acids store and transmit genetic information

◦ The individual molecules in nucleic acids are called nucleotides and are made

of a sugar, a phosphate group, and a nitrogenous base

◦ The two kinds of nucleic acids are DNA and RNA

◦ The order of the individual nucleotides in a DNA or RNA molecule determine

the traits in an organism

PROTEINS

◦ Proteins are composed of carbon, hydrogen, oxygen and

nitrogen.

◦ The building block of a protein is an amino acid.

PROTEINS

◦ Proteins are organic molecules that form muscles, transport

oxygen (hemoglobin), and act as hormones and enzymes. Most

importantly, proteins determine how our bodies look and

function.

◦ Proteins are made of amino acids linked together by a peptide

bond.

Proteins

◦There are 20 different amino acids

found on our planet

◦Amino acids are the building

blocks of proteins.

◦Different combinations of amino

acids form different proteins

◦Each protein has a specific role or

job in an organism

◦Some proteins control the rate of

reactions and regulate cell

processes

◦Some proteins are used to form

bones and muscles

◦Some proteins transport substances

into or out of cells and fight disease

Just like any tool, a protein’s function is

determined by its shape.

Chemical Reactions and Enzymes

◦A chemical reaction is a process

that changes one set of chemicals

into another set of chemicals

◦Reactant: the chemicals entering

the reaction

◦Product: the chemicals made from

the reaction

Many chemical reactions require

energy in order for them to occur;

humans eat food in order to supply

energy for these chemical reactions

Energy needed to

start a chemical

reaction is

activation energy.

A Catalyst is a

substance that

speeds up the

rate of a chemical

reaction.

Activation Energy

w/o Catalyst

Activation Energy

with catalyst

Enzymes

◦Enzymes are proteins that act as

biological catalysts in chemical

reactions that occur in cells

◦Enzymes are tools; they are NOT

part of the chemical reaction and

are the same after the reaction as

they were before the reaction

◦Enzymes lower the activation

energies, allowing the

chemical reaction to occur

without needing so much

energy to get started

◦The reactants of enzyme-

catalyzed reactions are called

substrates

◦Enzymes are

very specific

to a particular

substrate;

they will only

“fit” that

particular

molecule

◦Enzymes can

be affected

by pH and

temperature

ENZYME EXAMPLE

◦ Lactase is the enzyme that breaks down lactose in the body.

Lactose is a major type of sugar found in milk.

◦ Salivary amylase is the enzyme that breaks down food in your

mouth before it enters your digestive tract.

How enzymes get their name:◦ Enzymes are usually named by using the name of the substrate

with ---ase added.

◦ EX: lactase

ENZYMES

◦ Enzymes are NOT used up or changed in the reaction.

◦ The place where the enzyme attaches to the substrate is the

active site.