metabolism

Question 1

Glycogenesis

Answer 1

make glycogen = decrease glucose (& ATP) w/ glycogen synthasae

Question 2

Glycolysis

Answer 2

decrease glucose in blood (bc break glucose for ATP) by insulin

Question 3

Glycogenolysis

Answer 3

break down glycogen w/ glycogen phosphorylase-P @ a1-6 branches = make glucose (increase) by glucagon

Question 4

Gluconeogenesis

Answer 4

make glucose (increase) from non carbohydrate precursors by glucagon

Question 5

What are the energy stores in the human body?

Answer 5

Liver, muscle, fat

Question 6

Which hormone do you expect to function in case of high concentration of plasma glucose? What do you call this process?

Answer 6

Insulin, glycolysis

Question 7

Which hormone do you expect to function in case of low concentration of plasma glucose? What do you call this process?

Answer 7

Glucagon, gluconeogenesis

Question 8

precursor for gluconeogenesis

Answer 8

oxaloacetate

Question 9

Fasting requires all the glucose to be synthesized from ——–precursors?

Answer 9

non-carbohydrate

Question 10

How many steps is bypassed in gluconeogenesis bc it’s irreversible? WHat are they?

Answer 10

3

Step 1, 3, 10

Question 11

ATP gluconeogenesis consume

Answer 11

6 ATP

Question 12

gluconeogenic precursors & where located in body?

Answer 12

• ALanine from muscle
• glycerol fromadipose tissue
• lactate from muscle, RBC, Cori cycle

Question 13

HOw does liver work during exercise? (cori cycle)

Answer 13

Muscle works anaerobic = lactate => liver => glucose via cori cycle

Question 14

In Cori Cycle, how many phosphates are consumed?

Answer 14

4

Question 15

name of cancer responsible for loss of adipose tissue & skeletal muscle mass. (may work similar to cori cycle)

Answer 15

Cachexia (Cachectic cancer)

Question 16

Difference b/w cori cycle and cachexia in terms of glucose turnover

Answer 16

Cori cycle: 20%

Cachexia: 50%

Question 17

When would the alanine or Cahill cycle be used?

Answer 17

presence of NH3 due to muscle degeneration

Question 18

Concept of Alanine or Cahill cycle

Answer 18

Muscle degeneration = NH3 -> + pyruvate = alanine -> liver -> gluconeogenesis via alanine cycle

Question 19

conversion of glucose to glycogen and where it’s stored

Answer 19

Glucose -> glucose -6-phosphate -> gucose-1-phosphate -> glycogen & stored in muscle and liver as glycogen.

Question 20

Which organs can’t undergo gluconeogenesis and why?

Answer 20

brain and muscle bc lack glucose-6-phosphatase enzyme

Question 21

What is GLUT2 function? and how is it upregulated?

Answer 21

glucose carrier/transporter which is upregulated when [Glu] >30mM

Question 22

What’s the major e- donor in reductive biosynthesis?

Answer 22

NADPH

Question 23

Importance of ketone bodies

Answer 23

make energy when starving and no glucose

Question 24

Which AA are ketogenic

Answer 24

lysine & leucine

Question 25

Which AA are ketogenic and glucogenic?

Answer 25

Isoleucine

Threonine, Tryptophan, Phenylalanine and Tyrosine

Question 26

3 types of ketone bodies and are they soluble or insoluble in water

Answer 26

• acetone, acetoacetate and β-hydroxybutyrate

- soluble

Question 27

downside of ketogenesis

Answer 27

ketone bodies make blood acidic (ketocidosis)

Question 28

Can the liver use ketone bodies for energy? why?

Answer 28

NO bc lack beta-keotacyl-coa-transferase

Question 29

General process of making ketone bodies and use it for energy

Answer 29

Starvation -> FA (adipose tissue) in liver-> oxidise to acetyl coa -> ketone bodies -> acetyl AoA (by B-ketoacyl-coa-transferase) in tissues except in liver-> ATP

Question 30

Glycogen is broken down by?

Answer 30

1. Glycogen phosphorylase-P: remove glucose residues from non-reducing end
2. Glucan transferase: debranch
3. Alpha-1,6-glucosidase: cleave a1-6 branch

Question 31

Where is GLUT 2 & GLUT 4 located?

Answer 31

2: liver
4: muscle

Question 32

In feeding state how is glycogen stimulated to be made (processes)?

Answer 32

1. insulin released
2. stimulates protein phosphatase-1 => activate glycogen synthase
3. glycogen produced

Question 33

in fasting state how is glycogen stimulated to be broken down? (process)

Answer 33

1. glucagon & epiniphrine (adrenaline)
2. => Inc. cAMP => Inc. protein kinase => phosphorylase kinase => activates glycogen phosphorylase-P
3. break down glycogen = glucose

Question 34

Name of the disease that’s characterised by accumulation of abnormal amounts or types of glycogen in tissues

Answer 34

glycogen storgae disease (GSD)

Question 35

difference of GSD type 1a, 1b, 1c & 1d (deficiency in)

Answer 35

1a: G1Pase deficient
1b: Translocase T1 deficient
1c: Translocase T2 deficient
1d: transporter that translocates free glucose molecules

Question 36

GSD type 2 (aka Pompe disease) is due to (a) deficiency and _ _ _ in most tissues is detected

Answer 36

a. alpha-1,4-glucosidase

b. normally structured glycogen

Question 37

GSD type 3 has glycogen deposited in _ & _

Answer 37

liver & skeletal muscles

Question 38

Diagnosis for people w/ GSD. And how blood glucose levels ae maintained throughout the night (2 ways)

Answer 38

a. biopsy of muscle of liver tissue
b. - carbohydrate solutions through a stomach tube
- uncooked cornstarch every 4-6hrs

Question 39

Which organ has the most important site for gluconeogenesis during starvation?

Answer 39

kidney

Question 40

Consuming alcohol may lead to diabetic ketoacidosis and accumulation of ——-, inhibit the process of gl_ bc it prevents _

Answer 40

NADH
gluconeogenesis
oxidation of lactate to pyruvate