Proteins: amino acids
Learning Objectives
Know what an amino acid is. Know how many amino acids there are.
Know that different proteins have different amino acids (e.g., albumin in eggs is one of the few “complete” proteins).
Hey everyone today we’re going to be learning about the building blocks, structures and roles of Proteins. Focusing heavily on amino acids.
Proteins are among the most abundant organic molecules in living systems and are way more diverse in structure and function than other classes of macromolecules. A single cell can contain thousands of proteins, each with a unique function. Although their structures, like their functions, vary greatly, all proteins are made up of one or more chains of amino acids.
(pull up amino acid figure that’s below)
Amino acids are the monomers that make up proteins. A protein is made up of one or more linear chains of amino acids, each of which is called a polypeptide. There are 20 types of amino acids commonly found in proteins.
We’ll come back to amino acids and polypeptides, I just wanted to get you thinking of them for a second and to know that there’s 20 commonly found.
Right now we’re going to quickly go over enzymes and hormones,
Enzymes act as catalysts in biochemical reactions, meaning that they speed the reactions up. Each enzyme recognizes one or more substrates, the molecules that serve as starting material for the reaction it catalyzes. Different enzymes participate in different types of reactions and may break down, link up, or rearrange their substrates.
One example of an enzyme found in your body is salivary amylase, which breaks amylose (a kind of starch) down into smaller sugars. Amylose doesn’t taste very sweet, which is why starchy foods often taste sweeter if you chew them for longer: you’re giving salivary amylase time to get to work.
One more example of an enzyme is lactase. People who are dairy intolerant, or lactose intolerant, can’t digest lactose because their body doesn’t produce the enzyme, lactase. –side note, If you do have this issue, there’s over the counter supplements that one can take before eating dairy that has lactase added to it, making it possible to consume dairy without the side effects.
Now we’re going to move onto hormones. Hormones are long-distance chemical signals released by endocrine cells (like the cells of your pituitary gland). They control specific physiological processes, such as growth, development, metabolism, and reproduction. While some hormones are steroid-based, others are proteins, commonly called peptide hormones.
For example, insulin is an important peptide hormone that helps regulate blood glucose levels. When blood glucose rises (for instance, after you eat a meal), specialized cells in the pancreas release insulin. The insulin binds to cells in the liver and other parts of the body, causing them to take up the glucose. This process helps return blood sugar to its normal, resting level.
A protein’s shape is critical to its function, m