Glycolysis

Question 1

Glucose to Glucose 6 Phosphate by ____

Answer 1

hexokinase

Question 2

hexokinase ___ glucose —> G6P

Answer 2

phopshorylates

Question 3

hexokinase is not present in the ___

Answer 3

liver, there is glucokinase

Question 4

what happens wtih G6P?

Answer 4

there is no transporter for G6P so it is stuck at the cell

Question 5

γ-Phosphoryl of ATP is transferred to the ___ of Glu by Hexokinase

Answer 5

C6 hydroxyl

Question 6

when does the liver export glucose?

Answer 6

when glucose is low

this is why the liver has a less aggressive heokinase (glucokinase)

Question 7

difference between affinity of glucokinase compared to heoxkinase?

Answer 7

Liver Glucokinase has an affinity for Glu that’s 500-fold weaker than that of Hexokinase

Question 8

G6P enters glycolysis?

Answer 8

when the cell needs energy

Question 9

G6P is converted to F6P by

Answer 9

phopshoglucose isomerase

Question 10

action of phopshoglucose isomerase on G6P

Answer 10

PGI isomerizes an aldose to a ketose

Question 11

after phopshorylation at the C1 hydroxyl group what is produced? why?

Answer 11

two equal 3 carbon fragments

due to PGI setting the stage for an aldol cleavage between C3/C4 (requires a carbonyl at C2)

Question 12

phopshofructokinase transfers a γ-phosphoryl of ATP to the ___ of F6P to make it F1,6 BP

Answer 12

C1 hydroxy

Question 13

fructose 6-phopshate is converted into F 1,6 BP by

Answer 13

phosphofructokinase

Question 14

___ plays a central role in the regulation of Glycolysis

Answer 14

phopshofructokinase

Question 15

what cleaves fructose 1,6, biphosphate

Answer 15

aldose

Question 16

products?

Answer 16

Question 17

what is dihydroxyacetone converted to?

Answer 17

GAP, the other product of the cleavage of f 16 BP

Question 18

differene between DHAP and GAP?

Answer 18

DHAP is a KETOSE

GAP is an ALDOSE

Question 19

what converts DHAP to GAP?

Answer 19

tripose-P-isomerase

Question 20

GAP and DHAP are both

Answer 20

trioses

Question 21

GAP gets ____ to be converted to 1,3-BPG by GAP dehydrogenase?

Answer 21

oxidized and phosphorylated

Question 22

____ converts GAP to 1,3 BPG

Answer 22

GAP dehydrogenase

Question 23

first step in glycolysis where you MAKE atp?

Answer 23

Question 24

1,3 PBG is converted to 3PG by

Answer 24

phosphoglycerate kinase

Question 25

how many ATPs does this rxn produce?

Answer 25

2

Question 26

this is an example of \_\_\_

Answer 26

substrate level phopshorylation

Question 27

Phosphoglycerate Mutase moves the phosphoryl of 3PG to the ____ to get \_\_\_\_.

Answer 27

C2 hydroxyl to give 2PG

Question 28

\_\_\_converts 3PG to 2PG

Answer 28

Phosphoglycerate Mutase

Question 29

2PG is converted to PEP by

Answer 29

enolase

Question 30

mechanism of conversion of 2PG by enolase to PEP

Answer 30

2PG is dehydrated

Question 31

two examples of substrate level phopsphorylation

Answer 31

1. **1,3-BPG to 3PG** 2, **PEP to pyruvate **

Question 32

describe the steps from GAP -------------\> pyruvate

Answer 32

Question 33

how many ATP are made from GLucose to Pyruvate?

Answer 33

4 ATP

Question 34

what is the NET agian of ATP from glucose to two pyruvate

Answer 34

net gain of 2

Question 35

what is the net gain of NADH from glucose to two pyruvate?

Answer 35

2 NADH

Question 36

Under anaerobic conditions, pyruvate is **reduced** by glycolytic NADH to \_\_\_

Answer 36

give lactate

Question 37

Under aerobic conditions, glycolytic NADH is ____ and pyruvate enters the CAC

Answer 37

indirectly oxidized by oxidative phosphorylation

Question 38

enzyme that converts pyruvate to lactate?

Answer 38

lactate dehydrogenase

Question 39

when pyruvate is being converted to lactate, the __ carbon of pyruvate get **a hydride transer** with a pronation of the hydroxyl rgroup

Answer 39

C2 carbon

Question 40

galactose is converted to ___ to enter glycolysis

Answer 40

G6P

Question 41

\_\_\_ and ____ are converted to F6P to enter glycolysis

Answer 41

mannose and fructose

Question 42

fructose is converted to ___ in the liver to enter glycolysis

Answer 42

GAP

Question 43

order in which frucotse, galactose, and mannose enter the glycolsis pathway

Answer 43

Question 44

what converts fructose to F6P in tissues other than the liver?

Answer 44

hexokinase

Question 45

what converts fructose to 2GAP in the liver?

Answer 45

1. Fructokinase 2. F1P Aldolase 3. Glyceraldehyde Kinase 4. Trios-P Isomerase

Question 46

Deficiencies in ___ cause liver damage and hypoglycemia

Answer 46

F1P Aldolase

Question 47

Deficiencies in F1P Aldolase cause ___ and \_\_\_

Answer 47

liver damage and hypoglycemia

Question 48

enzymes invovled in the conversion of mannose to F6P?

Answer 48

1. hexokinase 2. phopsomannose isommerase

Question 49

enzymes invovled in teh converstion of galactose to G6p?

Answer 49

1. Galactokinase 2. a UMP Transferase 3. an Epimerase 4. Phosphoglucomutase

Question 50

• A deficiency in ____ results in Galactitol formation which causes cataracts

Answer 50

Galactokinase

Question 51

A deficiency in Galactokinase results in Galactitol formation which causes\_\_\_

Answer 51

cataracts

Question 52

A deficiency in the UMP transferase causes ____ (2)

Answer 52

mental retardation and liver failure

Question 53

A deficiency in the _____ causes mental retardation and liver failure

Answer 53

UMP transferase

Question 54

when second galactose comes along, the first is converted to \_\_\_

Answer 54

G1P

Question 55

first step in breakdown of glycogen

Answer 55

glycogen phosphorylase produces G1P

Question 56

first step in conversion of G1P to glycogen?

Answer 56

UTP is added to G1P to pshoprylate it to become **UDP-glucose**

Question 57

The phosphoryl of G1P condenses with the ____ of UTP to give UDP-Glu + PPi

Answer 57

α-phosphoryl

Question 58

what is needed to pull the G1P to UDP-glucose reaction to completion?

Answer 58

pyrophosphatase cleaves PPi to 2Pi

Question 59

The C4 hydroxyl of the Glu unit at the end of a **Glycogen chain** condenses with the\_\_\_ carbon of UDP-Glu

Answer 59

**C1**

Question 60

enzyme invovled in conversion of UDP-glucose to glycogen?

Answer 60

glucose synthase

Question 61

from the a(1,4) terminal chains of glycogen brnaching enzyme removes a 7 residue grafment from chaisn of at least ___ residues

Answer 61

11 (needs 4 left over)

Question 62

branching enzymes converts from the a(1,4) terminal chains of glycogen to a ___ chain of glycogen

Answer 62

a(1-6) glycogen chain this introduces a branch, so now have 3 branches instead of 2

Question 63

Glycogen polymers may contain up to\_\_\_ Glu units each

Answer 63

120,000

Question 64

Glycogen polymers contribute up to ___ of the rotal mass of 10% of th eottal mass of the liver

Answer 64

10 percent

Question 65

When Glu is needed, Phosphorylase breaks the glycosidic bond at the end of a Glycogen chain by addition of

Answer 65

a phosphate to give G1P

Question 66

how long can glucose be removed from glycogen?

Answer 66

until terminal glucose on the chain is **within 4 residues of a branch point** where steric hinderance prevents further digestion by Phosphorylase

Question 67

• Debranching enzyme transfers a ____ from the stub to the C4 hydroxyl at the end of another branch

Answer 67

trisaccharide

Question 68

two functions of debranching enzyme?

Answer 68

1. transfers a trisaccharide froms tub of c4 gtdroxyl at the end of another branch 2. also cleaves the reamin a,16 glu by hydrolysis

Question 69

difference betw **Phsophoglucomutase in conversion of G1P to G6P** and **Phosphoglycerate Mutase in conversion of 3PG to 2PG?**

Answer 69

Ser-P intermediate instead of His-P in Phsophylycomutase

Question 70

cost of temproailry storing glu in glycogen in muscle/liver from g6p -\> glycogen -\> g6p

Answer 70