lecture 26

Question 1

what does the diversity and versatility of proteins come from?

Answer 1

• chemical diversity of the constituent amino acid side chains
• flexibility of polypeptide chain
• large number of ways in which polypeptide chains interact with different amino acids and fold

Question 2

what is the difference of each amino group?

Answer 2

the R-group side chain

Question 3

what type of bond is formed between the carboxyl group of the first amino acid and amino group of the second amino acid?

Answer 3

covalent peptide bond

Question 4

what is released when a peptide bond forms?

Answer 4

water

Question 5

what is in the peptide plane?

Answer 5

carboxyl oxygen, carboxyl carbon, and amide nitrogen of next amino acid

Question 6

if there is no interference from the side chains in a peptide molecule, what happens?

Answer 6

since the nitrogen-alpha carbon bond and the carbon-alpha carbon bond are both single bonds, it allows for free rotation

Question 7

what are the two ends of the primary structure of a protein called?

Answer 7

N-terminus(amino terminus) and C-terminus(carboxyl terminus)

Question 8

what is the simplest secondary structure?

Answer 8

beta turn

Question 9

what level of protein structure is a porin?

Answer 9

secondary structure

Question 10

what is the most common secondary structure element?

Answer 10

alpha helix

Question 11

what is a disulfide bridge?

Answer 11

post-translational modification that is reversible and mainly only found in secreted proteins(not intracellular proteins) because of the reducing nature of the cytoplasm

Question 12

what is metal binding?

Answer 12

a post-translational modification that binds a metal ion to several amino acid side chains to make a single protein forming an internal metal chelate

Question 13

what type of motif is a zinc-finger motif?

Answer 13

sequence motif

Question 14

what is a set of contiguous secondary structural elements that have a specific function?

Answer 14

functional/structural motif

Question 15

what is a compact region of protein structure capable of stable folding independent of a large protein and having a specific FUNCTION?

Answer 15

protein domain

Question 16

what are the TWO types of reversible effector molecule binding?

Answer 16

acetylation and phosphorylation

Question 17

what are the TWO types of irreversible effector molecule binding?

Answer 17

ubiquitination and methylation

Question 18

what is the most important effector molecule to bind in post translational modifications for stability of the protein?

Answer 18

glycosylation(addition of carbs to specific amino acids) which acts as a switch function