An enhancer

a. can be located upstream of a promoter.

b. can be located downstream of a promoter.

c. can be located a variable distance from the promoter.

d. is always located within 1 kb of the promoter.

e. can be cell-type-specific.

#Question id: 10281

#Unit 6. System Physiology – Plant

Gluconeogenesis is particularly important in plants such as the castor oil plant Ricinus communis and sunflower that store carbon in which form .

#Question id: 10282

#Unit 6. System Physiology – Plant

In the glycolytic reaction one of the step is catalyzed by ATP-dependent phosphofructokinase is essentially irreversible, at the same step which one of the following enzyme used in gluconeogenesis, both of the enzymes are ATP dependent.

#Question id: 10283

#Unit 6. System Physiology – Plant

How to Phosphofructokinase-1 (PFK-1) and Fructose 1,6-Bisphosphatase are reciprocally regulated ?

a) ATP inhibits PFK-1 by binding to an allosteric site and lowering the affinity of the enzyme for its substrate fructose 6-phosphate

b) citrate is also an allosteric regulator of PFK-1, high citrate concentration increases the inhibitory effect of ATP

c) FBPase-1, is strongly inhibited (allosterically) by AMP; when the cell’s supply of ATP is low (corresponding to high AMP), the ATP-requiring synthesis of glucose slows

d) AMP inhibits PFK-1 by binding to an allosteric site and lowering the affinity of the enzyme for its substrate fructose 6-phosphate

Which of the following statements of regulation of enzyme is correct?

#Question id: 10284

#Unit 6. System Physiology – Plant

Allosteric regulation of enzyme multisubunit or multiactive site shows cooperativity with the sigmoidal graph between substerate conc. v/s Activity,

a) Cell contain NADH, FADH2 and ATP, that inhibits the allosteric enzyme activity by lowering the affinity with its substate, graph shifts towards B from control

 b) A- shows low ATP, the Km for fructose 6-phosphate is relatively low, the affinity of the enzyme with its substate is relatively high

 c) Haemoglobin, Phosphofructokinase, Phosphate dehydrogenase complex, α-ketoglutarate dehydrogenase complex, these all enzymes shows characteristics of sigmoidal graph

 d) When ATP is high, Km for fructose 6-phosphate is greatly increased- this activity shown by B in the graph

 e) fructose 2,6-bisphosphate binds to its allosteric site on PFK-1, it increases the enzyme’s affinity for its substrate fructose 6-phosphate and reduces its affinity for the allosteric inhibitors ATP and citrate- shown in graph by A

 Which of the following  combination of the enzyme activity with its substate correctly shown;

#Question id: 10285

#Unit 6. System Physiology – Plant

Some of the statements given shows the activity of PFK-1 and PFK-2, which of the following statements incorrectly shown these enzyme activity?

#Question id: 10286

#Unit 6. System Physiology – Plant

The enzyme aldolase, catalyzes a reversible aldol condensation, Fructose 1,6-bisphosphate is cleaved to yield two different triose phosphates, glyceraldehyde 3-phosphate, an aldose, and dihydroxyacetone phosphate, a ketose. There are two classes of aldolases such as;

A) Class I aldolases

B) Class II aldolases

i) Found in animals and plants

ii) Found in in fungi and bacteria

iii) formation of protonated Schiff base on enzyme and its active site contain lysine residue

iv) do not form the Schiff base intermediate and a zinc ion at the active site is coordinated with the carbonyl oxygen at C-2

In which of the following option is the given enzyme with its correct statements?