1. Proteins
Biomolecule #3

2. Protein Structure
Elements: carbon, hydrogen, oxygen, nitrogen, and sometimes sulfur and share the same general structure.
Monomer of proteins are called amino acids.
There are 20 different amino acids, and proteins are composed of various combinations.
Polymer is called a polypeptide.

3. Meet the monomer –Amino acid
3 main parts
Amino group NH2
Carboxyl group COOH
R group (side chain)
each of the 20 types
of amino acids have
a unique R group
Please draw the monomer.

4. Protein Structure – Special Bond
Amino acids join together to form proteins with a special bond called a peptide bond.
Forms between the amino acid group of one amino acid and the carboxyl group of another
Proteins are also called polypeptides because of this bond.

5. Proteins Shape
A protein’s shape is determined by the order that amino acids are joined in
The shape/structure of a protein determines its function
Hemoglobin Antibody Enzymes Polymerase

6. Protein Shape Primary (a) – Straight chains
Secondary (b) – Coils and Pleats
Tertiary (c) – Bends and Folds
Quaternary (d) – Globs

7. Protein Functions
Enzymes - proteins that allow chemical reactions to occur in living things
Antibodies – proteins that protect the body from infection
Structure – cytoskeleton, hair, nails, muscles, spider web, silk, feathers ,horns, hooves etc….
Hormones – chemical messengers
Cell membrane – proteins can act as channels through the cell membrane
Receptor proteins found on the membrane transmit signals to the inside of the cell
Hemoglobin – protein found in blood that carries oxygen

9. Enzymes Video

10. Enzymes Vocabulary
Enzyme – catalysts that lowers the activation energy of a reaction (make the reaction go faster).
Catalyst – something that speeds up the reaction
Activation Energy – the amount of energy required for a reaction to “go”
Substrate – the substance an enzyme acts on
Active Site – where the substrate binds to the enzyme
Denature – loses shape or can no longer be useful; can happen due to change in pH or temperature
Inhibitors – thing that stops an enzyme from working

11. Enzymes
Active Site
Enzyme
Substrate

12. Temperature and pH greatly effect enzymes.
There is an optimal temp and pH for every reaction.

13. Enzymes
Look at the following graph and determine the temperature at which this enzyme has the greatest rate of activity.

14. How do enzymes help you? Food Digestion
DNA Copying: helicase and polymerase break and reform the bonds needed to make more DNA.
amylase (found in your saliva) helps break down starch
lipase helps break down fats in your body (lipids)
Energy Production – many different enzymes are needed during cellular respiration to make ATP.
lactase helps break down lactose in dairy products (carbohydrate)
protease helps break down proteins in your body