Respiration is

anabolic + exergonic
catabolic + exergonic
catabolic + endergonic
anabolic + endergonic

Which one is the product of aerobic respiration ?

Malic acid
Ethyl alcohol
Lactic acid
Pyruvic acid

In glycolysis, during oxidation electrons are removed by–

Molecular oxygen
ATP
Glyceraldehyde
NAD⁺

How many moles of carbon dioxide are produced by the complete oxidation of 1 mole of pyruvate?

Solution

Pyruvate is a three-carbon compound, (CH₃C[O]C[O]OH), which on complete oxidation releases three moles of CO₂.

During the early stages of alcoholic fermentation there is a high rate of growth of yeast. After some time the rate decreases. Which of the following conditions in the culture medium is least likely to have caused this?

Depletion of glucose
Depletion of oxygen
Depletion of mineral salts
Accumulation of waste products

Solution

Yeast causes alcoholic fermentation without using oxygen and hence depletion of oxygen has no effect on the metabolism or growth of yeast cells.

Certain organism are allowed to respire anaerobically for sometime. If they are transferred to an oxygen containing medium,the rate of aerobic respiration of these organisms is always faster as compared to the rate of respiration of organisms which are given O₂ since the beginning. This might be due to one of the following reasons.

Due to faster rate of oxidation, the end products accumulate in the aerobic organisms reduces the rate of its respiration.
In anaerobically respiring animals there are extra enzymes to increase the rate of the oxidation
In anaerobically respiring animals the end product produced is common with that of aerobic respiration and therefore the rate of oxidation is hastened
In aerobically respiring organisms an intermediate product of anaerobic respiration is further oxidized.

Solution

Anaerobic respiration produces pyruvic acid which is the raw material for aerobic oxidation. So if the organism was already producing pyruvic acid it will hasten the rate of Krebs cycle.

When protein molecules are used as fuel for aerobic cellular respiration, _____ are produced as waste.

amino groups
fatty acids
sugar molecules
molecules of lactic acid

Solution

Prior to their entry into the reactions of cellular respiration, the amino group is removed from amino acids.

Why is glycolysis considered one of the first metabolic pathways to have evolved ?

It relies on fermentation, which is characteristic of the archaebacteria and eubacteria.
It produces much less ATP than does the electron transport chain and chemiosmosis.
It relies totally on enzymes that are produced by free ribosomes, and bacteria have only free ribosomes and no bound ribosomes.
It is nearly universal, is located in the cytosol, and does not involve O₂

In which of the following reaction of glycolysis, a molecule of water is removed from the substrate ?

Fructose –6 – phosphate → fructose 1, 6 – bisphosphate
3 – phosphate glyceraldehyde → 1, 3 –bisphosphglyceric acid
PEP → pyruvic acid
2 – Phosphoglycerate → PEP

Conversion of fructose–6–phosphate to fructose 1,6-diphosphate is catalysed by

Phosphofructose kinase
Aldolase
Hexokinase
None of these

Solution

Fructose 6-phosphate + ATP \(\begin{matrix}Phosphofructokinase, \, Mg^{2+} \\ \\ -------------\rightarrow \end{matrix}\) Fructose 1, 6 – diphosphate + ADP.

UnAttempted

0

Attempted

0

Correct

0

Wrong

0

Complete