You are interested in a new type of autosomal dominant mutation that gives purple eyes in Drosophila. You have a true-breeding purple-eyed line carrying a mutation that you call pr-1. You have isolated a second purple-eyed mutation that you call pr-2, which you have established in a true-breeding line that also carries a recessive marker st, which gives stubby legs. You cross a fly from the pr-1 line to a fly from the st, pr-2 line producing F1 females which you then cross to males from a true breeding st line (normal eyes). From this cross, 1000 progeny flies can be categorized into four different phenotypic classes:

                   

What is the phenotype of a pr-1 pr-2 double mutant?

#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?

#Question id: 10287

#Unit 6. System Physiology – Plant

Glyceraldehyde 3-phosphate dehydrogenase avtive site contain

#Question id: 10288

#Unit 6. System Physiology – Plant

 If all the ATP are radiolabelled in the cytosol, then predict about radioactivity of each compound.

 a) All enzyme  of glycolysis will be radiolabelled except 2-phophoglycerate and phosphenol pyruvate

 b) 2-phophoglycerate and phosphenol pyruvate are radiolabelled only the next cycle of glycolysis after cytosolic ATP radiolabelling

 c) 1,3 bisphosphoglycerate will be radiolabelled at 1 and 3 both position

 d) 2-phosphoglycerate are not radiolabelled because its enzyme phosphoglycerate mutase active site contain histidine residue exchange phosphate group from 3-phosphoglycerate

 which prediction about radiolabelling is incorrect?

#Question id: 10289

#Unit 6. System Physiology – Plant

If C6 of glucose is radiolabelled, which carbon of Dihydroxyacetone phosphate and glyceraldehyde 3-phosphate  is radiolabelled?