4.1.1 Integrative Metabolism I

Question 1

Describe how tryptophan can be converted to melatonin

Answer 1

Question 2

Describe the other recycling pathway b/t the liver and muscle.

Answer 2

Question 3

What is the key control enzyme in glycolysis?

Answer 3

Phosphofructokinase

Question 4

What is used in the glycogen synthesis? What is required?

Answer 4

Branching enzymes; UDP-glucose and a primer

Question 5

Glycogen is what type of storage?

Answer 5

Short-term; Used in glycolysis and oxidative metabolism

Question 6

What are some of the branchpoints off of pyruvate and acetyl CoA?

Answer 6

Question 7

What is the main control factor of the pentose phosphate pathway?

Answer 7

Concentration of NADP+

Question 8

Answer

Answer 8

B. Glucose

Question 9

What are some of the activators/stimulators/inhibitors of acetyl CoA carboxylase?

Answer 9

Activator: Citrate

Stimulator: Insulin

Inhibitors: Glucagon and Palmitoyl CoA

Question 10

What are two key branch points in the urea cycle?

Answer 10

Arginine and Ornithine

Question 11

What is the key control enzyme in fatty acid synthesis?

Answer 11

Acetyl CoA Carboxylase

Question 12

What type of reaction is used to remove glucose off of glycogen?

Answer 12

Phosphorolysis

Question 13

Describe the process through which glucose can lead to the generation of ketone bodies

Answer 13

Question 14

How do debranching enzymes work?

Answer 14

Question 15

How/where are carbohydrates stored within the human body?

Answer 15

Glycogen - Liver, Muscle

Glucose - Extracellular

Question 16

Describe when these enzymes (glycogen synthase, phosphorylase, phosphorylase kinase, protein phosphatase-1 inhibitor) are activated or inactivated?

Answer 16

Question 17

Where does the debranching enzyme begin working on glycogen?

Answer 17

Begins at the non-reduced ends

Question 18

Answer

Answer 18

The pentose phosphate cycle

Question 19

What are the 7 principles of metabolic regulation?

Answer 19

1. Substrate supply
2. Allosteric interactions
3. Covalent modifications
4. Enzyme levels
5. Compartmentation
6. Organ specialization
7. Endocrine controls

Question 20

What is a key control step (enzyme) in gluconeogenesis?

Answer 20

Fructose-1,6-Bisphosphatase

Question 21

What are some of the uniftying themes in intermediary metabolsim?

Answer 21

Question 22

Describe the circular steps of the TCA cycle

Answer 22

Question 23

Describe the step-wise pathways of glycolysis/gluconeogenesis b/t glucose and pyruvate.

Answer 23

Question 24

What is glycogen?

Answer 24

A highly-branched structure with (1-6) branches occuring every 4th residue

Question 25

Describe the conversion of tyrosine to epinephrine

Answer 25

Question 26

Describe the pattern of liver glycogen content over a 24 hr period

Answer 26

Varies

Question 27

Electron donor in reductive synthetic reactions?

Answer 27

NADPH

Question 28

What enzyme aids in the conversion of tyrosine to thyroxine (T4)? What does this enzyme require?

Answer 28

Thyriod peroxidase; H2O2

Question 29

Electron acceptor in oxidative degradative reactions

Answer 29

NAD+

Question 30

What are the three main compartments in cells?

Answer 30

Mitochondrial matrix Cytosol Interplay of both compartments

Question 31

Answer

Answer 31

Fructose-1,6-Bisphosphatase

Question 32

What are some of the activators/inhibitors/stimulators of Fructose-1,6-bisphospatase?

Answer 32

Activator: Citrate Inhibitors: AMP, F-2,6-BP, Insulin Stimulators: Glucagon, cortisol

Question 33

Describe what metabolic pathways occur in the following compartments: Mitochondrial matrix, cytosol, both.

Answer 33

Question 34

Answer

Answer 34

C. Acetyl CoA Carboxylase

Question 35

What are some activators/inhibitors of phosphofructokinase?

Answer 35

Activators: F-2,6-BP, AMP Inhibitors: ATP and citrate

Question 36

What enzyme converts T4 to T3

Answer 36

5'-deiodinase

Question 37

Answer

Answer 37

B. Phosphofructokinase 1

Question 38

What are the key metabolic branch points of glucose metabolism

Answer 38

Question 39

Describe the recycling pathway that exists b/t the liver and muscle. What is this cycle known as?

Answer 39

Cori Cycle

Question 40

What reaction must occur in the liver for it to leave the tissue and enter the blood?

Answer 40

The bottom reaction

Question 41

Summarize the urea cycle

Answer 41

Question 42

What is an important enzyme in the pentose phosphate pathway?

Answer 42