proteins

Question 1

what are proteins?

Answer 1

• form very important structural and functional molecules in living organisms
• make up more than 50% of the dry mass of most cells.
• biologically functional molecule with a very specific three-dimensional shape made up of 1 or more polypeptide chains

Question 2

what are the functions of proteins?

Answer 2

structural; collagen and keratin in tendons and nails
catalytic; enzymes like amylase, speed up biochemical reactions
movement; actin and myosin, part of cytoskeleton of cells, involved in moving cell contents around
transport; haemoglobin in rbc, transports oxygen around the body
immune function; antibodies, immunoglobulin, detect and hold onto disease causing agents.

Question 3

what are proteins made up of?

Answer 3

• amino acid monomers
• C,H,O,N in 20 amino acids
• • S in 2 amino acids
• contain an amino group, carboxyl group, variable R group

Question 4

how do the chemical and physical properties of the R group affect the characteristics of an amino acid?

Answer 4

1. nonpolar variable group makes the amino acid hydrophobic
2. polar variable group makes the amino acid hydrophilic
3. charged variable group makes the amino acid hydrophilic

Question 5

what is a polypeptide?

Answer 5

chain of amino acids linked together by peptide bonds

Question 6

what can proteins by classified as?

Answer 6

fibrous proteins; structural proteins such as keratin, collagen and elastin
globular proteins; functional proteins such as immunoglobulin, haemoglobin and amylase
the role of a protein is related to its structure.