Question

how much ATP will be produced based only on the number of acetyl coA units, from B oxidation of stearic acid? stearic acid is an 18 carbon, saturated fatty acid

(a)108ATP

(b) 148ATP

(c)18ATP

(d)27ATP

(2) which stage of the complete oxidation of glucose produces the largest ATP yield?

(a)oxidation of decarboxylation

(b) glycolysis

(c) citric acid cycle

(d)anaerobic conditions

(3) reaction #7 of the citric acid involves the formation of a secondary alcohol in malate from a double bond in fumarate.what type of reaction is this?

(a) hydrolysis

(b) isomerization

(c)hydration

(d) oxidation

(4) arrange the following in the order in which they appear in electron transport

CoQ, FADH, cytochrome c(Fe3+

,

Answer 1

1 Ans: b

Explanation : To calculate the no of AT we should first know how many acetyl coA molecules are produced per cycle of beta oxidation

For that the formula is n/2 where n = no of carbon atoms in fatty acid

Here for stearic acid , n=18

So using the formula we get 18/2 = 9 acetyl coA per cycle and 1 acetyl coA produces 12 ATP by citric acid cycle . So 9 acetyl coA would produce 108 ATPs . But that's not the final answer because beta oxidation also produces NADH+H+ and FADH2 and both contribute to Total ATP so have to them into consideration also

So , to find total ATP , first need to know how many cycles are run to completely oxidise stearic acid

For that the formula is n/2 -1

So it'll be 18/2 -1 = 9-1 = 8 cycles to completely oxidise stearic acid to acetyl coA molecules.

1 cycle = 1 NADH+H+ and 1 FADH2

So 8 cycles = 8 NADH+H+ and 8 FADH2

And we know 1 NADH+ H+ would produce = 3 ATP and 1 FADH2 would produce = 2 ATP

So 8 NADH+ H+ will produce 8 × 3=24 ATP

And 8 FADH2 will produce 8 × 2 = 16 ATP

So overall Total ATP produced are 108 + 24 + 16 = 148 ATPs by stearic acid

2 Ans: c

Explanation: Glucose first undergoes glycolysis during which NET gain of ATP is only 2 , oxidative decarboxylation which is a intermediate step between Glycolysis and citric acid cycle doesn't contribute directly to ATP

And finally the Highest yield of ATP is in citric acid cycle which oxidises acetyl coA one cycle produces 12 ATPs ( Highest)

3 Ans : c

Explanation : when water is added across a double bond OH group ( alcohol) is formed so its hydration reaction ; addition of H2O

4 Ans: The complete Sequence is as follows

FADH ------CoQ ----------Cytochrome c------ Cytochrome a3 ------ O2