Structure of proteins

Question 1

What is a peptide bond?

Answer 1

a bond formed between the carboxyl group of one amino acid and the amino group of another.

Question 2

What is the primary structure of proteins?

Answer 2

The Amino acid sequence.

Question 3

What are psi and phi bonds?

Answer 3

Psi bonds are formed before an alpha carbon and phi bonds are formed after the alpha carbon.

Question 4

What is the secondary structure of proteins?

Answer 4

Alpha helices and beta sheets.

Question 5

Characteristics of alpha helices?

Answer 5

Right handed helical structure. Every 4th amino acid interacts via H-Bonds.

Question 6

Characteristics of beta sheets?

Answer 6

Composed of adjacent parallel or anti parallel beta strands. Fully extended amino acids rather than coiled.

Question 7

What is the tertiary structure of proteins?

Answer 7

Called domains, folding of secondary structures into certain forms.

Question 8

What is the Quaternary structure of proteins?

Answer 8

Sometimes proteins associate with themselves.
dimer: 2 proteins
trimer: 3 proteins
Tetramer: 4 proteins
Pentamer: 5 proteins