Charlotte Jakes
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Nutrition and Metabolism Quiz on Glycogen Synthesis and Regulation, created by Charlotte Jakes on 30/12/2019.

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Charlotte Jakes
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Glycogen Synthesis and Regulation

Question 1 of 48

1

Why is there glycogen in the liver?

Select one of the following:

  • Glucose homeostasis

  • The liver's only source of glucose

  • Gluconeogenesis

  • Gives structural support to hepatocyte membranes

Explanation

Question 2 of 48

1

Which is correct of glycogen in the liver?

Select one of the following:

  • Anabolism initiated by insulin
    Catabolism initiated by glucagon

  • Anabolism initiated by glucagon
    Catabolism initiated by insulin

Explanation

Question 3 of 48

1

The only source of glucose to supply the muscles is the glycogen.

Select one of the following:

  • True
  • False

Explanation

Question 4 of 48

1

Which linkages occur between adjacent glucose monomers in glycogen?

Select one of the following:

  • a-1,4 links

  • a-1,6 links

Explanation

Question 5 of 48

1

Which linkages occur between glucose monomers and their neighbouring molecules in branches in glycogen?

Select one of the following:

  • a-1,4 links

  • a-1,6 links

Explanation

Question 6 of 48

1

The enzymes at the beginning and/or end of a biosynthetic pathway will be tightly regulated.

Select one of the following:

  • True
  • False

Explanation

Question 7 of 48

1

Why, in biosynthetic pathways, is at least one enzymatic reaction irreversible?

Select one of the following:

  • To prevent accumulation of metabolites

  • More finer degree of control

  • To prevent unwanted by-products

  • To increase the rate of the pathway

Explanation

Question 8 of 48

1

What is the first reaction in the synthesis of glycogen?

Select one of the following:

  • Phosphorylation of glucose

  • Formation of UDP glucose

  • Addition of protein primer

  • Addition of UDP glucose

Explanation

Question 9 of 48

1

Where is hexokinase present?

Select one of the following:

  • All tissues

  • The liver only

  • The liver and pancreatic B cells

  • The liver and pancreatic a cells

Explanation

Question 10 of 48

1

Glucokinase is present in the liver and pancreatic B cells only.

Select one of the following:

  • True
  • False

Explanation

Question 11 of 48

1

Phosphorylation of glucose to glucose-6-phosphate is carried out by which enzyme(s)?

Select one of the following:

  • Glucokinase or hexokinase

  • Glucose phosphorylase

  • Glucokinase only

  • Hexokinase only

Explanation

Question 12 of 48

1

What is the role of phosphoglucomutase in glycogen synthesis?

Select one of the following:

  • Isomerisation of glucose 6-phosphate to glucose 1-phosphate

  • Phosphorylation of glucose to glucose 6-phosphate

  • Phosphorylation of glucose to glucose 1-phosphate

  • Addition of UTP to glucose

Explanation

Question 13 of 48

1

Which enzyme catalyses the formation of UDP glucose from UTP and glucose 1-phosphate?

Select one of the following:

  • UDP-glucose pyrophosphorylase

  • UDP-glucose pyrophosphatase

  • UDP-glucose synthase

  • Gluco-UTPase

Explanation

Question 14 of 48

1

What is the structure of uridine triphosphate (UTP)?

Select one of the following:

  • Ribose, uracil and three phosphates

  • Deoxyribose, uracil and three phosphates

  • Ribose, uracil and two phosphates

  • Ribose, adenine and three phosphates

Explanation

Question 15 of 48

1

What is a co-product of UDP glucose formation?

Select one of the following:

  • PPi

  • Pi

  • UTP

  • ADP

Explanation

Question 16 of 48

1

What does UTP react with on glucose 1-phosphate to form UDP glucose?

Select one of the following:

  • The phosphate group of glucose 1-phosphate

  • The hydroxyl group of the 6th carbon

  • The hydroxyl group of the 2nd carbon

  • The hydrogen of the 3rd carbon

Explanation

Question 17 of 48

1

What amino acid does glycogenin bind to in the protein primer?

Select one of the following:

  • Tyrosine

  • Phenylalanine

  • Threonine

  • Glutamate

Explanation

Question 18 of 48

1

Which carbon of UDP-glucose does tyrosine bind to in the protein primer?

Select one of the following:

  • 1st

  • 2nd

  • 3rd

  • 6th

Explanation

Question 19 of 48

1

When the tyrosine-glycogenin protein primer binds to UDP-glucose, UDP is cleaved off.

Select one of the following:

  • True
  • False

Explanation

Question 20 of 48

1

Which enzyme catalyses the addition of the tyrosine-glycogenin primer to UDP-glucose causing the cleavage of UDP?

Select one of the following:

  • Glucosyltransferase

  • Tyrosine transferase

  • Glycogenin synthase

  • UDP hydrolase

Explanation

Question 21 of 48

1

How does the chain extend from glucose once it has been bound to the tyrosine-glycogenin primer?

Select one of the following:

  • 1,4 linkages between primed glucose and UDP-glucose

  • 1,6 linkages between primed glucose and UDP-glucose

  • 1,4 linkages between primed glucose and primed UDP-glucose

  • 1,6 linkages between primed glucose and primed UDP-glucose

Explanation

Question 22 of 48

1

Which statement is true of branching in glycogen?

Select one of the following:

  • A portion of the long chain is moved to branch up and form 1,6 linkages

  • An initial 1,6 linkage is formed off the core chain and 1,4 linkages are formed from that

  • Branching requires another primed UDP-glucose molecule

  • Branching does not require UDP glucose, only regular glucose

Explanation

Question 23 of 48

1

Fill the blank spaces to complete the text.

Fill in the blanks below to summarise the synthesis of glycogen.
1. First, is phosphorylated to . This is catalysed by or in the liver.
2. Then, is isomerised to . This is catalysed by .
3. reacts with to form , releasing in the process. This reaction is catalysed by .
4. The enzyme binds a protein primer in the form of the amino acid bound to to the 1st carbon of . This causes the cleavage of .
5. Additional monomers join via linkages in reactions catalysed by .
6. This process repeats to form a chain.
7. Portions of the core chain are transferred to form linkages with the chain itself to form branches.

Explanation

Question 24 of 48

1

The active form of glycogen synthase is what?

Select one of the following:

  • Not phosphorylated

  • Phosphorylated

Explanation

Question 25 of 48

1

What enzyme do we require to activate glycogen synthase?

Select one of the following:

  • Protein phosphatase

  • Protein kinase

Explanation

Question 26 of 48

1

Insulin activates a protein phosphatase which dephosphorylates glycogen synthase to activate it.

Select one of the following:

  • True
  • False

Explanation

Question 27 of 48

1

What happens first in glycogen breakdown?

Select one of the following:

  • Phosphorylation of glycogen to release glucose 1-phosphate monomers

  • Phosphorylation of glycogen to release glucose 6-phosphate monomers

  • Transfer of branches onto the core chain

  • Cleavage of a-1,6 linkages

Explanation

Question 28 of 48

1

What enzyme carries out the phosphorylation of glucose monomers in glycogen during breakdown?

Select one of the following:

  • Glycogen phosphorylase

  • Glycogen phosphatase

  • Hexokinase

  • Glycogen hydrolase

Explanation

Question 29 of 48

1

What does glycogen transferase do?

Select one of the following:

  • Transfers glycogen chains onto the core chain leaving behind 1 branched monomer with a a-1,6 linkage

  • Transfers glycogen chains entirely onto the core chain

  • Isomerises glucose 1-phosphate to glucose 6-phosphate

  • Catalyses the hydrolysis of a-1,6 linkages

Explanation

Question 30 of 48

1

Which enzyme cleaves a-1,6 linkages on glycogen?

Select one of the following:

  • a-1,6-glucosidase

  • a-1,6-kinase

  • a-1,6-hydratase

  • a-1,6-catalase

Explanation

Question 31 of 48

1

Glucose 1-phosphate from the breakdown of glycogen is converted to glucose 6-phosphate by phosphoglucomutase

Select one of the following:

  • True
  • False

Explanation

Question 32 of 48

1

Glucose-6-phosphate is only converted to glucose in the liver

Select one of the following:

  • True
  • False

Explanation

Question 33 of 48

1

Fill the blank spaces to complete the text.

Fill in the blanks below to describe glycogen breakdown.
1. First, an phosphorylates glucose monomers to break their linkages and release them. This is catalysed by .
2. Then, glycogen are removed and added to the core chain by . This leaves behind a single branched glucose monomer with an linkage.
3. This linkage is broken by .
4. is isomerised to by .
5. In the liver, is converted to by the enzyme. The muscle does not have this enzyme, so its enters the pathway.

Explanation

Question 34 of 48

1

The active form of glycogen phosphorylase is what?

Select one of the following:

  • Phosphorylated

  • Not phosphorylated

Explanation

Question 35 of 48

1

What enzyme do we require to activate glycogen phosphorylase?

Select one of the following:

  • Protein kinase

  • Protein phosphatase

Explanation

Question 36 of 48

1

By what mechanism is glycogen protein kinase activated?

Select one of the following:

  • Secondary messenger with cAMP signalling

  • Secondary messenger with IP3 signalling

  • Increase in cytosolic Ca2+

  • Cytosolic receptor signalling

Explanation

Question 37 of 48

1

Fill the blank spaces to complete the text.

Adrenaline activates glycogen breakdown in the .
Glucagon activates glycogen breakdown in the .
Insulin activates glycogen breakdown in .

Explanation

Question 38 of 48

1

Where does calcium released from the sarcoplasmic reticulum bind on glycogen phosphorylase kinase?

Select one of the following:

  • Calmodulin domain

  • Histidine residues

  • Active site

  • Tyrosine residues

Explanation

Question 39 of 48

1

What effect does calcium in muscle cells have on glycogen breakdown?

Select one of the following:

  • Activates glycogen phosphorylase kinase to activate glycogen phosphorylase to initiate glycogen breakdown

  • Activates glycogen phosphorylase phosphatase to deactivate glycogen phosphorylase and prevent glycogen breakdown

Explanation

Question 40 of 48

1

Why is it important that calcium can regulate glycogen breakdown in the muscles?

Select one of the following:

  • Our muscles need energy to contract but we don't always need adrenaline and our blood glucose isn't always low

  • Provides more powerful contraction

  • Provides more resistance to fatigue

  • In case glycogen concentration is low

Explanation

Question 41 of 48

1

What effect does AMP have on glycogen phosphorylase?

Select one of the following:

  • Allosteric activation

  • Allosteric inhibiton

  • Competitive inhibition

  • Covalent activation

Explanation

Question 42 of 48

1

Why is it important that AMP concentration regulates glycogen breakdown?

Select one of the following:

  • High AMP indicates low ATP so glycogen breakdown is necessary

  • Provides more powerful contraction

  • AMP is present in all cells all the time

  • AMP can cross the cell membrane

Explanation

Question 43 of 48

1

ATP is an allosteric inhibitor of glycogen phosphorylase.

Select one of the following:

  • True
  • False

Explanation

Question 44 of 48

1

Fill the blank spaces to complete the text.

Fill in the blanks to describe each glycogen storage disease.
disease is caused by defective glucose 6-phosphatase.
disease is caused by defective lysosomal glycosidase.
disease is caused by defective glycogen phosphorylase.

Explanation

Question 45 of 48

1

Which of the following are logical symptoms of Von Gierke's disease?

Select one of the following:

  • Hypoglycaemia, lactic acidosis, enlarged liver

  • Accumulation of glycogen in lysosomes, muscle weakness, cardiac failure

  • Exercise intolerance, red/brown urine following excercise

Explanation

Question 46 of 48

1

Which of the following are logical symptoms of Pompe's disease?

Select one of the following:

  • Accumulation of glycogen in lysosomes, muscle weakness, cardiac failure

  • Hypoglycaemia, lactic acidosis, enlarged liver

  • Exercise intolerance, red/brown urine following exercise

Explanation

Question 47 of 48

1

Which of the following are logical symptoms of McArdle's disease?

Select one of the following:

  • Exercise intolerance, red/brown urine following exercise

  • Accumulation of glycogen in lysosomes, muscle weakness, cardiac failure

  • Hypoglycaemia, lactic acidosis, enlarged liver

Explanation

Question 48 of 48

1

What causes red/brown urine following exercise in those with McArdle's disease?

Select one of the following:

  • Myoglobin excretion due to muscle breakdown

  • Haemoglobin excretion due to vessel rupture in muscles

  • Myoglobin excretion due to use in respiration

  • Myoglobin excretion due to use in removal of lactate

Explanation

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