FORMATION OF ACETYL COA

Question 1

WHICH STEPS ARE IRREVERSIBLE?

Answer 1

STEP 1: GLUCOSE -> GLUCOSE 6 PHOSPHATE
STEP 3: FRUCTOSE 6 PHOSPHATE -> FRUCTOSE 1 6 BIPHOSPHATE
STEP 10: PEP -> PYRUVATE

Question 2

WHAT IS THE DIFFERENCE BETWEEN HEXOKINASE AND GLUCOKINASE?

Answer 2

HEXOKINASE:
- CAN BE FOUND IN ALL CELLS
- HAS LOW KM VALUE
- HAS LOW VMAX
- HAS HIGH AFFINITY TOWARD GLUCOSE
- IS INHIBITED BY THE GLUCOSE 6 PHOSPHATE
- IS NOT INDUCIBLE
- DEFICIENCY CAUSE HAEMOLYTIC ANEMIA
- INVOLVE IN MAINTAINING THE INTRACELLULAR GLUCOSE CONC.

GLUCOKINASE:
- CAN BE FOUND IN THE LIVER AND B ISLET CELL OF PANCREAS
- HAS HIGH KM VALUE
- HAS HIGH KM
- HAS LOW AFFINITY TOWARDS GLUCOSE
- IS INHIBITED BY THE FRUCTOSE 6 PHOSPHATE
- IS INDUCIBLE
- PTS WITH DIABETES MELLITUS SHOW LESS ACTIVITY
- INVOLVED IN MAINTAINING THE BLOOD GLUCOSE CONC.

Question 3

WHEN WILL THE PFK 1 BECOME ACTIVATED?

Answer 3

WHEN:
- FRUCTOSE 2 6 BP
- AMP/ADP
IS HIGH

Question 4

STATE THE CAUSE OF PFK1 BECOME DEACTIVATED.

Answer 4

• CITRATE
• HIGH ATP
• LOW PH

Question 5

WHAT IS HAPPENING DURING WELL FED STATE?

Answer 5

DURING WELL FED STATE:
- THE INSULIN/GLUCAGON RATIO IS HIGH
- INDICATING THE LEVEL OF INSULIN IS HIGH
- CAMP TO REDUCE
- PROTEIN KINASE A REDUCE
- TRIGGER DEPHOSPHORYLATION OF PFK2 AND FBPASE-2
- DEPHOSPHORYLATION OF PFK2 -> ACTIVE
- DEPHOSPHORYLATION OF FBPASE-2 -> DEACTIVE
- ACTIVATION OF PFK2 -> HIGH AMOUNT OF FRUCTOSE 2, 6 BP
- ACTIVATE THE PFK 1
- FRUCTOSE 1,6 BIPHOSPHATE INCREASE

Question 6

STATE THE IMPORTANCE OF PYRUVATE REDUCE TO LACTATE.

Answer 6

• REGENERATION OF NAD+
• CORI CYCLE

Question 6

STATE THE IMPORTANCE OF PYRUVATE REDUCE TO LACTATE.

Answer 6

• REGENERATION OF NAD+
• CORI CYCLE

Question 7

WHENEVER THE CELL’S ATP SUPPLY IS DEPLETED, WHICH OF THE FOLLOWING ENZYME’S ACTIVITY IS INCREASE FIRST?
A. HEXOKINASE
B. PYRUVATE KINASE
C. GLUCOKINASE
D. PFK 1

Answer 7

D. PFK 1

HEXOKINASE IS INHIBITED BY THE HIGH GLUCOSE 6 PHOSPHATE
PYRUVATE KINASE IS INHIBITED BY THE PHOSPHORYLATION OF CAMP DEPENDENT KINASE, HIGH ALANINE IN THE LIVER, HIGH ATP IN THE MUSCLE AND HIGH ACETYL COA
GLUCOKINASE IS INHIBITED BY THE HIGH FRUCTOSE 6 PHOSPHATE
PFK IS INHIBITED BY THE HIGH ATP, LOW PH AND CITRATE.
KEYWORDS IN QUEST: ATP SUPPLY LOW

Question 8

STATE 2 THINGS THAT CAN CAUSE PDH PHOSPHATASE TO BECOME ACTIVATED.

Answer 8

HIGH AMOUNT OF
- MG2+
- CA2+

Question 9

STATE 3 THINGS THAT CAN CAUSE PDH KINASE ACTIVATED.

Answer 9

HIGH AMOUNT OF
- NADH
- ATP
- ACETYL COA

Question 10

DEPHOSPHORYLATION OF PDH IS ____ (ACTIVE/ INACTIVE)

Answer 10

ACTIVE