Glycogen metabolism

Question 1

do plants have glycogen

Answer 1

nope

Question 2

what does glycogen do? (liver)

Answer 2

gets degraded by the liver to release glucose to help maintain blood glucose levels when they are low

Question 3

what does glycogen do? (muscle)

Answer 3

glucose that is released by glycogen is used to satisfy the muscles own energy needs during bursts of contraction

Question 4

which pathways does glycogen metabolism connect with? through what intermediate ?

Answer 4

glycolysis
PPP
gluconeogenesis in liver
glucose 6 phosphate

Question 5

what are the 2 types of bonds in glycogen

Answer 5

alpha 1,4 linkages
alpha 1,6 linkages

Question 6

what’s the importance in branched structures

Answer 6

they play a role in the rate that you can break it down, there is way more access points of glucose to be added or removed

Question 7

what is the input of energy required for the synthesis of glycogen ?

Answer 7

2 ATP for every glucose incorporated

Question 8

what is glycogen a storer of

Answer 8

glucose

Question 9

how much energy is yielded from the breakdown of glycogen

Answer 9

31 ATP for every glucose 6 phosphate produced when completely oxidized

Question 10

what is a part of glycogen synthesis that is not a part of glycogen breakdown

Answer 10

UDP-glucose (an activated form of glucose)

Question 11

what are mutase enzymes

Answer 11

isomers that change the position of a phosphate group in a molecule

Question 12

what is the biosynthetic pathway called for glycogen

Answer 12

glycogenesis

Question 13

what is the degrative pathway of glycogen called

Answer 13

glycogenolysis

Question 14

what is the activated precursor of glycogenesis

Answer 14

UDP-glucose

Question 15

what is the protein in glycogen

Answer 15

glycogenin

Question 16

what linkages does glycogen synthase only catalyze

Answer 16

a 1-4 linkages

Question 17

what’s the regulatory enzyme of glycogen synthesis

Answer 17

glycogen synthase

Question 18

what’s a strong allosteric activator of glycogen synthase?

Answer 18

glucose 6 phosphate

Question 19

is glycogen synthase a phosphorylated? is it active or not active?

Answer 19

it is not phosphorylated and it is the active form

Question 20

what influences the phosphorylation state of glycogen synthase?

Answer 20

insulin and glucagon

Question 21

what’s the principle enzyme that degrades glycogen

Answer 21

glycogen phosphorylase

Question 22

why is glycogen degraded by phosphorylase instead of hydrolysis ?

Answer 22

the released sugar is phosphorylated and doesn’t need to be phosphorylated at the expense of an ATP

Question 23

what linkages can glycogen phosphorylase cleave

Answer 23

alpha 1,4 linkages

Question 24

which glycogen phosphorylase is in muscle

Answer 24

glycogen phosphorylase b

Question 25

which form of glycogen phosphorylase is sensitive to allosteric modifiers

Answer 25

glycogen phosphorylase b. a form Is always active

Question 26

what are the two enzymes that trigger glycogen breakdown? which tissues do they happen in

Answer 26

epinephrine occurs in muscle
glucagon occurs in liver

Question 27

when is epinephrine released ?

Answer 27

when quick bursts of energy are needed

Question 28

how to reverse the process of glycogen breakdown

Answer 28

dephospho rylation or removal of phosphate groups