Chapter 25 (Protein Metabolism)

Question 1

Excess AA carbon skeletons can be salvaged for 3 things:

Answer 1

gluconeogenesis
fatty acid biosynthesis
ketone body synthesis

Question 2

Proteins are absorbed in the SI which has a pH of around ___

Answer 2

7

Question 3

Proteins are committed to degradation by conjugation with ___

Answer 3

ubiquitin

Question 4

E1 ubiquitin enzyme

Answer 4

Ubiquitin activation enzyme
Forms thioester bond with C-terminus of ubiquitin
Only one type

Question 5

E2 ubiquitin enzyme

Answer 5

Ubiquitin conjugating enzyme
Ubiquitin is transfered to a Cys-thiol of E2
20-30 kinds

Question 6

E3 ubiquitin enzyme

Answer 6

Ubiquitin Protein Ligase
Selects proteins for degradation
Over 100 kinds

Question 7

(T/F) More than one ubiquitin may be attached to a targeted protein

Answer 7

True

Question 8

Angelman syndrome is caused by a E___ deficiency

Answer 8

E3

Question 9

Which AA is located at the N-terminus of Ubiquitin

Answer 9

Valine

Question 10

26S Proteosome is also known as the ___ because it has ___

Answer 10

the executioner

14 subunits arranged in a barrel

Question 11

2 main functions of the 19S Regulatory Subunits

Answer 11

1. salvages ubiquitin

2. prevents partially proteolyzed proteins from escaping

Question 12

All transanimase reactions are (reversible/irreversible)

Answer 12

reversible

Question 13

Vitamin B6 is synthesized into ___ and is used as a ___

Answer 13

Pyridoxal Phosphate (PLP)
and e- sink during reactions such as transanimases and racimases (L to D)
forms a Schiff base

Question 14

The first step when using PLP as a coenzyme is always

Answer 14

creating a Schiff Base

Question 15

Study PLP mechanism

Answer 15

Do it

Question 16

A compound has to contain a ___ group in order to use PLP

Answer 16

amine