Exam 2 proteins

Question 1

what are the 4 types of globular proteins?

Answer 1

all a, all b, a/b, little secondary structure

Question 2

proteins with little secondary structure function by _____

Answer 2

binding with other molecules

Question 3

what is the most typical globular shape?

Answer 3

a/b

Question 4

___ ____ are amino acid sequences that are used repeatedly in the same protein or are found in different proteins

Answer 4

protein domains

Question 5

protein domains are typically __ to ___ amino acids long

Answer 5

40, 100

Question 6

do protein domains have the same or different function in different proteins?

Answer 6

different

Question 7

what are the two ways that protein domains are formed?

Answer 7

duplication of DNA segments within a gene, insertion of a DNA segment into another gene

Question 8

some domains are ____ and their function is unknown

Answer 8

neutral

Question 9

domains ____ over time and do not resemble the original

Answer 9

mutate

Question 10

what is the first step of protein folding?

Answer 10

new polypeptide forms segments of secondary structure, either a helix or beta sheets

Question 11

a helix and b sheet formation is due to what type of bonding?

Answer 11

hydrogen

Question 12

what is the second step of protein folding?

Answer 12

secondary structures form a globular shape

Question 13

how is a globular shape aquired?

Answer 13

through hydrophobic interactions

Question 14

what is the third step of protein folding?

Answer 14

tertiary structure is generated by adjustments to the folded structure

Question 15

____ ____ are proteins in the cell that bind new proteins and help bring parts together to get the proper 3D folding

Answer 15

molecular chaperones

Question 16

the intermediates of protein folding involve __-___ __ ___

Answer 16

R-side chain interactions

Question 17

____ ____ are misfolded, insoluble and aggregated proteins in brain cells

Answer 17

amyloid deposits

Question 18

what protein is misfolded in Alzheimer’s Disease?

Answer 18

amyloid-b

Question 19

what protein is misfolded in Parkinson’s Disease?

Answer 19

s synuclein

Question 20

___ and ____ are produced via the same type of forces

Answer 20

tertiary, quaternary

Question 21

quaternary structure allows for __ ____ between subunits of proteins

Answer 21

cooperative behavior

Question 22

how does hemoglobin exhibit cooperative behavior?

Answer 22

the binding of the first O2 molecule makes it easier for the 3 other O2 molecules to each bind to a subunit

Question 23

nitrite reductase, fumarase, hemoglobin, and methane hydroxylase all have what type of quaternary structure?

Answer 23

fixed number of subunits

Question 24

microtubules have what type of quaternary structure?

Answer 24

open

Question 25

___ ___ polymerize to form microtubules

Answer 25

tubulin dimers

Question 26

folding of a newly synthesized protein into the final 3D structure primarily involves the interactions of what?

Answer 26

amino acid side chains

Question 27

a protein has quaternary structure if it has more than ____ polypeptide chain

Answer 27

1

Question 28

_____ primarily hold together tertiary and quaternary structure

Answer 28

hydrophobic

Question 29

what 3 things hold together tertiary and quaternary structure?

Answer 29

hydrophobic interactions, hydrogen bonds, and ionic interactions

Question 30

____ ______ are when the interacting surfaces are identical and the resulting structure is dimeric

Answer 30

isologous interactions

Question 31

____ ______ involve nonidentical interfaces, and the surfaces must be complementary

Answer 31

heterologous associations

Question 32

reducing the protein’s surface to volume ratio increases its ____

Answer 32

stability

Question 33

what are the 4 benefits of quaternary association?

Answer 33

stability, genetic economy/efficiency, catalytic sites coming together, cooperativity