Exam 2

Question 1

Why is phosphorylation activating?

Answer 1

1. thermodynamics
2. kinetics
3. cell processes - atp concentration, signal transduction amplification
4. shape and charge complementarity
   (each Phos adds (-2) charge and (3+) H)

Question 2

Actase is inhibited by CTP

binding of CTP prefers the _______ state.
binding of ATP prefers the
________ state.

Answer 2

CTP - T/inactive state
t for tense
ATP - R/active state
r for relaxed - active

Question 3

Two levels of protein synthesis regulation

Answer 3

Transcription regulation @ promoters

translation regulation @ UTR

Question 4

Histone Acetylation ___ transcription

Answer 4

promotes

Question 5

histone phosphorylation _______ transcription

Answer 5

prevents

Question 6

histone methylation __________ transcription

Answer 6

promotes (with acetyl) or prevents (by self)

Question 7

heterochromatin

Answer 7

tightly packed chromatin -transcription off

Question 8

lipid structure

Answer 8

polar hydrophilic head

nonpolar hydrophobic tails

Question 9

saturated fatty acids

Answer 9

all single bonds

Question 10

fatty acids are numbered

Answer 10

from carboxyl-end
alpha-C
to methyl-end
omega-C

Question 11

fatty acids (naming)

• oic Acid = __________
• oate = __________

Answer 11

• oic Acid = protonated acid

- oate = deprotonated conjugate base

Question 12

(#:#)

Answer 12

( total # carbons: total # double bonds)

Question 13

TAGs vs. Waxes

Answer 13

triacylglycerol has glycerol with 3 fatty acid chains

waxes have alcohol with 2 chains

Question 14

contains phosphates

Answer 14

phospholipids

Question 15

contains sugars

Answer 15

glycolipids

Question 16

glycosphingolipids are important for

Answer 16

• ABO blood type antigens

- cell signaling

Question 17

are carbohydrates in contact with cytosol

Answer 17

no

they do attach to lipids and proteins on cell surface

Question 18

integral membrane proteins

Answer 18

span the entire width of the lipid bilayer

Question 19

peripheral membrane proteins

Answer 19

span only part of the width of the lipid bilayer

Question 20

in humans the rigidity of the membrane is determined by

Answer 20

fatty acid composition

cholesterol content