Proteins

Question 1

What are Proteins?

Answer 1

• polymers of amino acids which range in size (small to very very large)
• (folding is crucial to the function of the protein and is influenced largely by its sequence)

Question 2

How can amino acids be structured?

Answer 2

• can be non-ionized or ionized

- can have non-polar, polar, or partially charge side chains (amino or carboxylic)

Question 3

How do you number an amino acid?

Answer 3

From N-Terminus to C-Terminus

Question 4

What is the primary structure of a protein and how many different proteins are possible?

Answer 4

• Polypeptide backbone

- 2 kinds of amino acids; 100aa in one protein= 20^100 =10^130 possible combinations

Question 5

Why can polypeptides flex?

Answer 5

• Because groups on either side of each peptide bond can rotate about their single bonds
• Hydrogen bonds form between peptide chains

Question 6

What are the secondary structures of proteins?

Answer 6

• alpha - Helix
  
  • Every double bonded O bonds to hydrogen on every 4th Nitrogen
• beta - Pleated Sheets
  
  • Hydrogen bonds occur across sheets
• R Groups point out of the structure
• Peptide backbone hydrogen bonds determine secondary structure

Question 7

How are tertiary structures determined?

Answer 7

• interactions between secondary structures and their side chains

Question 8

How are quaternary structures made?

Answer 8

• made up of tertiary structures and held together by similar bonds