Protein Levels

Question 1

what is the primary level

Answer 1

sequence of amino acids in backbone

Question 2

what is the secondary level

Answer 2

localised organisation of backbone

Question 3

what are motifs

Answer 3

regular combination of secondary structure

Question 4

what are domains

Answer 4

a functional unit of protein

Question 5

what are teritary levels

Answer 5

overall shapes of protein

Question 6

what are quaternary levels

Answer 6

interactions between more than one polypeptide to form multimers

Question 7

what do sequences of amino acids fold into

Answer 7

alpha and beta sheets due to hydrogen bonding between N-H and C=O atoms

Question 8

what is the alpha helix

Answer 8

H-bonds form between 4th amino acids

Question 9

what is the beta sheet

Answer 9

H-bonds form between amino acids in different chains, can be parallel or anti-parallel

Question 10

how are motifs formed

Answer 10

alpha + beta + other features = motifs

Question 11

what is a helix-loop-helix

Answer 11

held together by weak interactions between mineral calcium and amino acids

Question 12

what is the zinc-finger

Answer 12

2 B strands and alpha helix held by interactions with zinc

Question 13

what is a coiled-coil

Answer 13

common in fibrous proteins and formed in alpha helixes with more hydrophobic residues

Question 14

what gives overall structure

Answer 14

secondary structures + motif or domain = overall structure

Question 15

what is an example of a domain

Answer 15

antibody variable domain

Question 16

what are prosthetic groups

Answer 16

small molecules from vitamins and minerals that give proteins extra functions

Question 17

what is retinol

Answer 17

found in purple-light sensitive proteins and comes from Vitamins A and is surrounded by a cage of alpha helixes

Question 18

what are multimers

Answer 18

multiple proteins assembled together

Question 19

what does changing the position of the binding site cause

Answer 19

long fibres/rings generate from the same protein

Question 20

proteins with the most interactions at the binding site mean what

Answer 20

interact most stably

Question 21

why is quaternary structure called alpha2beta2

Answer 21

4 subunits, fall into 2 types alpha or beta and these have different territory shape

Question 22

what are conformational changes

Answer 22

these are important for protein function and are initiated by binding of other molecules. They change from one stable folded shape to other