Tag: carbohydrate metabolism

Quizzes (9) Questions (178)

Questions Related to carbohydrate metabolism

Multiple choice hmp shunt alternative to glycolysis carbohydrate metabolism respiration bio-chemistry
Which of the following cellular metabolic processes can occur both in the presence or absence of ${O} _{2}$?

  1. Glycolysis

  2. Fermentation

  3. TCA cycle

  4. Electron transport coupled with chemiosmosis
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Glycolysis is an oxidative process in which one molecule of glucose is partially oxidised into two molecules of pyruvate in a series of enzyme catalysed reactions. Glycolysis, the major pathway for glucose metabolism, occurs in the cytosol of cells. It is a unique pathway that occurs aerobically as well as anaerobically and does not involve molecular oxygen.

Multiple choice hmp shunt alternative to glycolysis carbohydrate metabolism respiration bio-chemistry

Which one of the following hormone never reaches to cytoplasm?

  1. Estrogen

  2. FSH

  3. Progesterone

  4. Testosterone
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

FSH is a proteinaceous hormone. It does not enter its target cells, thus, it never reaches to cytoplasm. Instead, it binds to the receptor present on the cell membrane and activates a membrane bound enzyme that causes conversion of ATP to cAMP. This then alters the activities of enzyme in the cytoplasm.

Multiple choice hmp shunt alternative to glycolysis carbohydrate metabolism respiration bio-chemistry
Last ${e}^{-}$ acceptor during ETS is 
  1. ${O} _{2}$
  2. cyt $a$
  3. cyt ${a} _{2}$
  4. cyt ${a} _{3}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In electron transport chain, there are 7 electron acceptors, which are as follows $Co-Q\rightarrow Cyt\,\, b\rightarrow Cyt \,\,{c} _{1} \rightarrow Cyt \,\,c\rightarrow Cyt \,\,a\rightarrow Cyt \,\,{a} _{3}\rightarrow{O} _{2}$. Oxygen is the ultimate electron acceptor. These electron acceptors are present in a specific sequence along inner mitochondrial membrane.

Multiple choice bio-chemistry carbohydrate metabolism glucose metabolism the need for energy in living organism respiratory function

Which hormone secreted by thyroid gland ?

  1. Thyroxine

  2. Adrenalin

  3. Testosterone

  4. Phyrotrophic
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • The thyroid gland is composed of two lobes that are located on either side of the trachea.
  • Follicular cells of the thyroid gland synthesize two hormones, tetraiodothyronine or thyroxine ($T _4$) and triiodothyronine ($T _3$). 
  • Thyroid hormones play an important role in the regulation of the basal metabolic rate. 
  • Hence the hormone secreted by the thyroid gland is thyroxine.
  • So, the correct answer is 'Thyroxine'.
Multiple choice biology metabolism, cell respiration, and photosynthesis metabolism enzymes carbohydrate metabolism

In a reaction, reactants form a transition state, before the formation of products. Which of the following is affected by the action of enzyme?

  1. Products only

  2. Reactants only

  3. Transition state only

  4. Products and reactants

  5. Transition state and products
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Any chemical reaction includes the formation of transition state between reactant and product. Formation of transition state requires high energy content of reactant molecules for alignment of reacting groups, the formation of transient unstable charges, rearrangements of chemical bonds etc. The energy required for formation of the transition state is termed as activation energy. Enzymes enhance the rate of reaction by lowering down the activation energy of transition state. Thus, the correct answer is option C.

Multiple choice biology metabolism, cell respiration, and photosynthesis metabolism enzymes carbohydrate metabolism

An enzyme increases the rate of a reaction by?

  1. enzymes speed up reactions by lowering activation energy.

  2. Increasing the rate of random collisions of molecules

  3. Removing the product of the reaction so allowing it to continue

  4. Bringing the reacting molecules into precise orientation with each other
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation


  • Enzymes provide activation energy for the reactions they catalyze.
  • Catalysts lower the activation energy for reactions. 
  • The lower the activation energy for a reaction, the faster the rate. Thus enzymes speed up reactions by lowering activation energy.so, option A is correct.

Multiple choice biology metabolism, cell respiration, and photosynthesis metabolism enzymes carbohydrate metabolism

Biochemical reactions are carried out by enzymes

  1. By decreasing the energy of the reactants

  2. By increasing the activation energy of the reaction

  3. By decreasing the activation energy of the reaction

  4. By increasing the energy of the products of the reaction

  5. By decreasing the energy of the products of the reaction
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Any chemical reaction includes the formation of transition state between reactant and product. The energy required for formation of the transition state is termed as activation energy. Enzymes enhance the rate of reaction by lowering down the activation energy of transition state. Thus, the correct answer is option C.

Multiple choice biology metabolism, cell respiration, and photosynthesis metabolism enzymes carbohydrate metabolism

Energy released from enzyme-substrate interaction is

  1. Activation energy

  2. Binding energy

  3. Constant energy

  4. Variable energy
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The transition state is the state of the activated complex which is highly unstable and readily changes into the product.  At the transition state, the enzyme attaches to the substrate to form an enzyme-substrate complex by forming a weak chemical bond. Binding energy is the free energy that is released by the formation of weak interactions between a complementary substrate and enzyme.

So, the correct answer is option B.