Opening Questions1. What is the first thing that

comes to you mind when you hear the words:

MuscleBlood

Exercise

Learning Outcomes

• 1. Summarize the categories of • Proteins• 2. Provide examples of their

biological functions

PROTEINSAn organic molecule because

it contains CARBON attached to a hydrogen

They are long strands so they are considered

POLYMERS

Structure of a PROTEINProteins are long strands

(polymers) of AMINO ACIDSAmino Acids contain TWO

function groups(chemical uniqueness

attached to the carbon skeleton.(represent by letter R)

Amino Acids have one CARBOXYL (COOH) function group attached

to its carbon skeletonThe carboxyl group makes it

ACIDIC

They also have an AMINO (NH2) functional group attached to its

carbon skeleton.This is why we call them

AMINO ACIDS

The bonds that attach them to the carbon skeleton are covalent

bonds known as PEPTIDE BONDS

Many peptide bonds are called POLYPEPTIDE bonds

Scientists have discovered 50 different amino acids.

Living things only 20 of these to make proteins for use in their

bodies and cells.8 are considered essential

The other 12 are non-essential we can make in our bodies.

Amino Acid SIDE GROUPSSide groups make each amino

acid unique.There are three groups

IONICPOLAR

NON-POLAR

2 Main Shapes of a Protein The shape of a protein is important

to its function

Fibrous ProteinsHave a rod shape

Found in our hair, skin, ligaments, bones, fingernails and other

connective tissue

Globular ProteinsHave a round or irregular shape

Hemoglobin in our bloodEnzymes

• Proteins can be very small with only 100 amino acids Or they can be very large with more than 33,000 amino acids.• The reason larger proteins can

fit into our bodies is because they twist and fold on itself to fit in the body

Functions of Proteins1. Support

Ex Collagen in skinHuman Growth Hormone

2. MetabolismEx Amylase in saliva

3. RegulationEx. Hormones such as Insulin

4. TransportationEx Hemoglobin in Blood

5. DefenseEx. Antibodies in our white blood

cells6. Motion

Ex. Actin found in muscles for contraction

Wrap It Up

• 1. Proteins are ORGANIC because they contain CARBON attached to a hydrogen• 2. When amino acids bond

together they are held by peptide bonds

• 3. When they bond together they form long chains of amino acids called polypeptides • 4. Polypeptides form Proteins…• 5. Hence proteins are long chains of amino acids

• Monomers/Building blocks:• Amino acids• Elements: C, H, O and N• Functions: support, transportation,

regulation, metabolism, defense, motion• Examples: Hemoglobin, Insulin,

Human Growth Hormone (HGH)