Glycogenesis

Question 1

The glycogen synthesis occurs by a pathway similar to the reversal of glycogen breakdown

T/F

Answer 1

F

distinctly different from Glycogenesis

Question 2

Glycogenesis: Activation of Glucose

UDP glucose is formed from _____ and ____ by the enzyme _________

Answer 2

glucose-1-phosphate and UTP

UDPglucose pyrophosphorylase.

Question 3

Full meaning of UTP is _______

Answer 3

uridine triphosphate

Question 4

Glycogenesis: Glycogen Synthase

The _____ moiety from UDP-glucose is transferred to a ______ (_____) molecule. The primer is essential to accept the glycosyl unit. The primer is made up of a ____-____ complex.

In the next step,_________ are sequentially added by the enzyme ________

The glucose unit is added to the _______ ((outer or inner?) ) end of the glycogen primer to form an ______ glycosidic linkage and UDP is liberated.

Answer 4

glucose

glycogen primer

glycogenin

protein-carbohydrate

activated glucose units

glycogen synthase

nonreducing ; outer

alpha-1,4

Question 5

Glycogenin is a ____ protein, having ___ identical monomers.

An oligosaccharide chain of _____ units is added to each monomer.

Answer 5

dimeric

two

7 glucose

Question 6

Glycogenesis: Branching Enzyme

The glycogen synthase can add glucose units only in ____ linkage.

A branching enzyme is needed to create the ____ linkages.

When the chain is lengthened to ____ glucose residues, the branching enzyme will transfer a block of _____ glucose residues from this chain to another site on the growing molecule.

The enzyme amylo[1,4]→[__]_____ (branching enzyme) forms this alpha-1,6 linkage

To this newly created branch, further glucose units can be added in alpha- ___ linkage by _______

Answer 6

alpha-1,4

alpha-1,6

11 - 12

6 to 8

1,6; transglucosidase

1,4; glycogen synthase.

Question 7

The phosphorylated form of glycogen phosphorylase is (active or inactive ?)

glycogen synthase becomes (active or inactive?) on phosphorylation.

Answer 7

Active

Inactive

Question 8

Effect of ATP on

glycogen phosphorylase (liver) 
glycogen phosphorylase (muscle ) 
Glycogen synthase (liver)
Glycogen synthase (muscle )

Answer 8

Inhibit

Inhibit

Inhibit

Inhibit

Question 9

Effect of AMP on

glycogen phosphorylase (liver) 
glycogen phosphorylase (muscle ) 
Glycogen synthase (liver)
Glycogen synthase (muscle )

Answer 9

Activation

Activation

Lol

Lol

Question 10

Effect of glucose 6 phosphate on

glycogen phosphorylase (liver) 
glycogen phosphorylase (muscle ) 
Glycogen synthase (liver)
Glycogen synthase (muscle )

Answer 10

Lol
lol

Activate

Activate

Question 11

Effect of calcium on

glycogen phosphorylase (liver) 
glycogen phosphorylase (muscle ) 
Glycogen synthase (liver)
Glycogen synthase (muscle )

Answer 11

Activate

Activate

Lol

Lol

Question 12

von Gierke’s disease

______ enzyme is deficient

Xterized by :

______ ——-glycemia; _____megaly

Answer 12

Glucose-6-phosphatase

Fasting hypo

hepato

Question 13

Limit dextrinosis aka ____ disease

_____ enzyme is deficient

Xterized by:——— accumulates; _____ ——-glycemia; ____megaly

Answer 13

Cori’s

Debranching enzyme

Highly branched dextrin

Fasting hypo

Hepato

Question 14

Amylopectinosis aka ______ disease

______ enzyme is deficient

Xterized by: Glycogen with _______ ; ________megaly; ___ ——glycemia; death by age of ___

Answer 14

Anderson’s

Branching

few branches

hepatospleno

mild hypo

5

Question 15

McArdle’s disease

______ enzyme is deficient

Xterized by :_____ intolerance; accumulation of ______ in muscles

Answer 15

Muscle phosphorylase

Excercise

glycogen

Question 16

Hers’ disease

_______ enzyme is deficient

Xterized by : _____ ___glycemia; _____megaly; (better or worse?) prognosis than other types

Answer 16

Liver phosphorylase

Mild hypo

hepato

better

Question 17

The ____ cycle is the first metabolic pathway to be elucidated

Answer 17

urea

Question 18

The urea cycle is known as _______ urea cycle.

Answer 18

Krebs–Henseleit

Question 19

Urea cycle

As ——- is the first member of the reaction, it is also called as _____ cycle.

Answer 19

ornithine

Ornithine

Question 20

The two nitrogen atoms of urea are derived from two different sources, one from _____ and the other directly from the alpha amino group of _______.

Answer 20

ammonia

aspartic acid

Question 21

Urea cycle

Step 1

One molecule of ______ condenses with ___ in the presence of ___ molecules of ATP to form __________.

The reaction is catalysed by the (mitochondrial or cytoplasmic?) enzyme ________________.

Answer 21

ammonia

CO2

two

carbamoyl phosphate

Mitochondrial

carbamoyl phosphate synthetase-I (CPS-I)

Question 22

_____ reaction is the rate-limiting step in urea formation. It is irreversible and allosterically regulated.

Answer 22

CPS-I

Question 23

Urea cycle : Formation of Citrulline

The second reaction is (mitochondrial or cytoplasmic?) .

The _____ group is transferred to the NH2 group of _____ by _______________

Answer 23

Mitochondrial

carbamoyl

ornithine

ornithine transcarbamoylase (OTC)

Question 24

In urea cycle

The citrulline leaves the ____ and further reactions are taking place in ______.

Answer 24

mitochondria

cytoplasm

Question 25

Citruline is present or absent in tissue proteins milk blood.

Answer 25

Absent Present Absent

Question 26

Urea cycle: Formation of Argininosuccinate One molecule of ______ adds to citrulline forming a ____-______ bond which provides the 2nd nitrogen atom of urea. __________ catalyses the reaction This needs hydrolysis of ___ to ____ level, so two high energy phosphate bonds are utilized.

Answer 26

aspartic acid carbon to nitrogen Argininosuccinate synthetase ATP to AMP

Question 27

The PPi is an (activator or inhibitor?) of Formation of Argininosuccinate In urea cycle

Answer 27

Inhibitor

Question 28

Urea cycle : Formation of Arginine Argininosuccinate is cleaved by _______ to _____ and _____. The enzyme is inhibited by _____. But this is avoided by the ______ of the enzyme. The fumarate formed may be funnelled into TCA cycle to be converted to ____ and then to _____ to be transaminated to _____

Answer 28

argininosuccinate lyase arginine and fumarate fumarate cytoplasmic localization malate; oxaloacetate; aspartate

Question 29

Thus the urea cycle is linked to TCA cycle through _______. The 3rd and 4th steps taken together may be summarized as: Citrulline + aspartate → ________ +______

Answer 29

fumarate Arginine ; fumarate

Question 30

Urea cycle: Formation of Urea The final reaction of the cycle is the _____ of _____ to urea and ____ by ______

Answer 30

hydrolysis of arginine ornithine arginase

Question 31

The ornithine from urea cycle returns to the _____ to react with another molecule of _____ so that the cycle will proceed. Thus, ornithine may be considered as a catalyst which enters the reaction and is regenerated.

Answer 31

mitochondria carbamoyl phosphate

Question 32

The urea cycle consumes ___ high energy phosphate bonds

Answer 32

4

Question 33

The urea cycle and TCA cycle are interlinked, and so, it is called as "____________".

Answer 33

urea bicycle