FINAL - CH 6

Question 1

Protein Classifications by Function

Answer 1

metabolic enzymes
structural proteins
transport proteins
cell signaling proteins
genomic caretaker proteins

Question 2

Examples of Structural Proteins

Answer 2

Actin

Tubulin

Collagen

Question 3

Energy in active transport comes from

either:

Answer 3

ATP hydrolysis

Ionic gradient

Question 4

Membrane receptors

Answer 4

G-protein coupled receptors (GPCR)

Receptor tyrosine kinases

Question 5

Genomic caretakers

Answer 5

DNA polymerase

DNA ligase

Topoisomerase

DNA primase

Photolyase

Question 6

uses DNA template to guide synthesis of nascent DNA strands

Answer 6

DNA polymerase

Question 7

Seals newly formed DNA

Answer 7

DNA ligase

Question 8

assist DNA polymerase by preparing the DNA template for replication

Answer 8

DNA primase

Question 9

repairs thymine dimers that are formed as a result of UV radiation

Answer 9

Photolyase

Question 10

Heme is a ________ complex

Answer 10

Fe2+ -porphyrin

Question 11

Oxygen only binds to the prosthetic group with iron in its

_______

Answer 11

reduced state, ferrous state

Question 12

Myoglobin is composed of ________

Answer 12

8 alpha helices

Question 13

AAs involved in prosthetic group

Answer 13

His E7
Vall E11 Phe CD1
His F8

Question 14

His E7 binds to:

Answer 14

Oxygen with a hydrogen bond

Question 15

His F8 binds to:

Answer 15

Iron

Question 16

His E7 is the _____ histidine

Answer 16

Distal

Question 17

His F8 is the _____ histidine

Answer 17

Proximal

Question 18

Are hemoglobin subunits bound covalently or not?

Answer 18

Not

Question 19

When oxygen is unbound:

Answer 19

Heme group is puckered

Question 20

When oxygen binds:

Answer 20

Heme group is planar and F helix is moved closer to plane

Question 21

T -> R Transition involves:

Answer 21

breakage and reformation of many noncovalent interactions between

Question 22

____ are released during the T -> R Transition

Answer 22

Protons

Question 23

As one O2 binds:

Answer 23

the subunits change conformation, increasing the likelihood of additional O2 binding

Question 24

binding of a ligand at one site affects the binding of

another ligand at another site

Answer 24

Allosteric effects

Question 25

All the subunits must be in either T or R
form, model does not allow combinations
of T and R state.

Answer 25

Concerted Model of Allosterism

Question 26

Ligand binding progressively induces

conformational changes in the subunits

Answer 26

Sequential Model of Allosterism

Question 27

α1β1 has ____ residues that interact

Answer 27

35

Question 28

α2β2 has ____ residues that interact

Answer 28

19

Question 29

α-β interactions are mostly:

Answer 29

hydrophobic
H bonds
Ion pairs

Question 30

Solvent f channel ______ when O2 binds

Answer 30

Narrows

Question 31

How does Solvent f channel narrow:

Answer 31

α-β complexes shift by 15 degrees bringing β subunits closer together

Question 32

Helix F tilts and translates by _____

Answer 32

1 angstrom

Question 33

In the T state Fe is _____ out of the plane

Answer 33

0.6 angstroms