Bio- Glycogen

Front 1

which bonds are involved in glycogen (2)

Back 1

a-1,4 : polymer
a-1,6 : branches

Front 2

2 storage locations of glycogen

when are each broken down - for which cells

Back 2

LIVER: between meals to maintain BLOOD glucose & brain

MUSCLE: in physical ACTIVITY, energy via GLYCOLYSIS & TCA (not available for blood)

Front 3

2 sources of blood glucose and what times of the day are each important

Back 3

GLYCOGENOLYSIS BETWEEN meals
GLUCOENOGENESIS NIGHT

Front 4

how is glucose added to a growing glycogen polymer
- central protein
- how may glucose molecules can it attach
- enzyme

Back 4

glycogen PRIMER covalently attached to GLYCOGENIN - central catalytic protein
adds up to 4 glucose molecules to itself
GLYCOGEN SYNTHASE

Front 5

what needs to happen to glucose contained within cells to be used in metabolic pathways (glycogenisis), why
- what enzyme important in doing this
- product

Back 5

glucose trapped as glucose-6-phosphate...phosphorylated by PHOSPHOGLUCOMUTASE ↔ glucose-1-phosphate

Front 6

after phosphorlyation of glucose-6-phosphate by PHOSPHOGLUCOMUTASE → glucose-1-phosphate (in the cell)...
- what role does UTP play in preparing glucose-1-phosphate for glycogen synthesis

Back 6

UTP ACTIVATES glucose-1-phosphate to UDP-glucose

Front 7

which form of glucose is added to the growing glycogen strand (attached to glycogenin) by GLYCOGEN SYNTHASE

Back 7

activated UDP-glucose

Front 8

glycogen synthase can add UDP-glucose to growing glycogen polymer...
- which bonds does it introduce
- what can't it do

Back 8

a-1,4-glycosidic (polymer) bonds

cannot introduce branches (a-1,6)

Front 9

which is the rate-limiting enzyme in glycogen synthesis

Back 9

glycogen synthase

Front 10

since glycogen synthase cannot introduce new a-1,6-glycosidic branches, which enzyme does this

Back 10

TRANSGLYCOSYLASE: branching enzyme for glycogen, adds a-1,6-glycosidic bonds (approx every 10 residues)

Front 11

which enzyme releases glucose from glycogen, what is the reaction for this:
- substrates
- enzyme
- product

Back 11

GLYCOGEN PHOSPHORYLASE

[glucose]n + Pi (phosphate) → glucose-1-phosphate + [glucose]n-1

Front 12

what's the rate-limiting enzyme in glycogenolysis

Back 12

GLYCOGEN PHOSPHORYLASE

Front 13

when glucose-1-phosphate is released by GLYCOGEN PHOSPHORYLASE from glycogen (glucogenolysis), it isn't available for the cell...
- which enzyme changes this molecule to an available form for the cell glycolysis
- what is the product

Back 13

PHOSPHOGLUCOMUTASE;
glucose-1-phosphate ↔ glucose-6-phosphate

Front 14

in the LIVER, what process/ reaction is used to release glucose from glucose-6-phosphate for the blood

Back 14

de-phosphorylation --> for RBCs & brain

Front 15

in MUSCLE, what process/reaction is used to release glucose energy from glucose-6-phosphate for physical ACTIVITY

Back 15

GLYCOLYSIS --> TCA

Front 16

how does free glucose move between cells (i.e. which transport mechanism)

Back 16

glucose TRANSPORT molecules- FACILITATED DIFFUSION (e.g. GLUT2)

....glucose ONLYreleased from LIVER cells via de-phosphorylation (muscle uses glucose-6-phosphate in glycolysis, i.e. glucose not "free")

Front 17

which 2 hormones influence glucogenensis...
- which enzyme do they regulate

Back 17

INSULIN: +++stimulates glycogen synthase+++
GLUCAGON: ---inhibits glycogen synthase ---

Front 18

which 4 hormones influence glucogenolysis...
- which hormone do they regulate

Back 18

glycogen phosphorylase- rate limiting enzyme in glycogenolysis:
INSULIN ---inhibits --- GLUCAGON, ADRENALINE & CORTISOL +++stimulate+++