1. Proteins

2. Protein Made of amino acids
Amino acids are the building blocks of protein- they are organic acids
Contain nitrogen – sets them apart from lipids and carbohydrates (prefix amine means contains nitrogen).
Each amino acid has side chains that gives it its identity

3. The 20 Amino Acids What do they have in common? All contain Nitrogen
All contain Carbon, Hydrogen, and Oxygen
All have a carboxyl group

4. Essential / Non-Essential
Asparagine
Tyrosine
Serine
Valine
Proline
Tryptophan
Glycine
Threonine
Glutamine
Phenylalanine
Glutamic acid
Methionine
Cysteine
Lysine
Aspartic acid
Leucine
Arginine
Isoleucine
Alanine
Histidine
Non-Essential
Essential
Essential – amino acids the body does not produce. Must obtain through diet.
Non-Essential – amino acids produced by the body.

5. Amino Acids
The 20 amino acids are like letters and form different sequences
The number of protein combinations is greater than the number of English words (more than 100,000 unique proteins)
A single human cell may contain 10,000 different proteins

6. Protein Shape
Proteins are extremely large molecules with complex shapes
Shape determines function
Artist renderings of 6 different protein molecules. Each contains thousands of amino acids.

7. Protein Uses Creating DNA Catalyzing reactions in cells
Transporting other molecules
Structurally supporting cell walls
Immune responses (many proteins fight disease)
Red blood cells (hemoglobin) – transport oxygen throughout the body.
Involved in some way in virtually every cellular process

8. Dehydration Synthesis
The carboxyl (COOH) group on one amino acid reacts with the amide group (NH2) on the other.
Removal of water creates a C-N peptide bond. All amino acids are connected via peptide bonds.

9. Hydrolysis
The reverse of dehydration synthesis, hydrolysis breaks the peptide bond and restores the original amino acids.

10. Denaturation Proteins do not dissolve in water
The change in a protein’s shape brought on by
Heat
acids or bases
alcohol
They unfold.

11. Sources of Protein Complete Proteins (all 20 amino acids)
All meats and animal products- eggs, cheese, milk
Fish
Legumes - alfalfa, clover, peas, beans, lentils, mesquite, carob, soybeans (tofu and soy products), peanuts, tamarind
Buckwheat
Quinoa
Incomplete proteins
Nuts
Some grains / rice

12. Digestion
Proteins begin their digestion in the stomach, where an enzyme called pepsin begins to break down peptide bonds.
Smaller groups of amino acids move into the small intestine where they are broken down into single amino acids where they are absorbed.
Amino Acids are circulated through blood, where they are used for many different functions in the body.

14. Digestion Some more easily digested than others Animal proteins
complete proteins
easy to digest and absorb - 90%
Legumes
Also complete but harder to digest - 80%
Grains/ plants
Incomplete
Vary in ability to digest %

15. Role of proteins Support new tissue growth
Hemoglobin – red blood cells
Fluid and electrolyte balance – cell transfer

16. Hormones to regulate body functions
Immune system – large proteins act as antibodies to protect against disease
Provide energy, when carbs and fat in short supply – your body does not go to protein for energy unless it has to, as proteins are primarily used to maintain a multitude of functions in the body.