Tag: bio-chemistry

Questions Related to bio-chemistry

The number of ATP molecules produced during the production of 1 molecule of acetyl Co-A from 1 molecule of pyruvic acid is

bio-chemistry carbohydrate metabolism energy output living organisms and energy production respiration in cell

  1. 3 ATP.

  2. 8 ATP.

  3. 36 ATP.

  4. 38 ATP.

Show answer
Correct Option: A
Explanation:

Pyruvic acid is the end product of glycolysis. It is translocated into mitochondria for complete oxidation to carbon dioxide and water. Inside mitochondria first pyruvic acid is oxidatively decarboxylated into acetyl coA. In this process the three carbon atom containing pyruvic acid is converted to two carbon atom containing acetyl CoA and a molecule of carbon dioxide is released. The acetyl coA is fed into the Kreb's cycle. 

During oxidative decarboxylation of pyruvic acid one molecule of reduced coenzyme $NADH _2$ is synthesized. The reduced coenzyme $NADH _2$ can be metabolised by mitochondrial electron transport system, when one molecule of $NADH _2$ produces 3 ATP molecules by  the process of oxidative phosphorylation.

Chemosynthesizers can convert chemicals into biomass, and many types of chemosynthetic organisms congregate near hydrothermal vents, where chemicals are abundant.
Predict why there would be higher biomass and greater primary production of organisms living in the hydrothermal vent areas, in contrast to the areas outside the vent areas.

bio-chemistry carbohydrate metabolism energy output living organisms and energy production respiration in cell

  1. The vents release an abundance of chemicals the organisms living there can use in the production of energy molecules.

  2. The heat released from the vents oxidizes chemicals in the water that organisms consume.

  3. It is too cold outside the vent areas, so most of the organisms live within the vent areas.

  4. Predators are rare in the vent areas, so organisms rarely venture out beyond the immediate vent area.

Show answer
Correct Option: A
Explanation:

Hydrothermal vents are abundant in chemical substances that are released by the core of the earth. These vents are devoid of light and have a temperature of about 350$^o$C. Therefore, this habitat can help only those organisms to survive which do not use light as a source of energy, that is autotrophs of this food chain should be able to synthesize food from chemicals present in the surrounding- example archea while withstanding the extreme temperature

So, the correct answer is 'The vents release an abundance of chemicals the organisms living there can use in the production of energy molecules'

Which organisms are ultimately responsible for obtaining the energy required for life processes?

bio-chemistry carbohydrate metabolism energy output living organisms and energy production respiration in cell

  1. Anaerobic bacteria

  2. Fungi decomposing dead organisms

  3. Plants undergoing photosynthesis

  4. Animals undergoing respiration

Show answer
Correct Option: D
Explanation:
Respiration is a catabolic process that leads to formation of ATP molecules from the substrate, that can be utilized for performing various life processes
So, the correct answer is 'Animals undergoing respiration'

Both photosynthesis and cellular respiration are metabolic processes that occur in eukaryotic cells. Each process involves several steps and chemical reactions.
All of the following occur during the processes of photosynthesis and cellular respiration except

bio-chemistry carbohydrate metabolism energy output living organisms and energy production respiration in cell

  1. The production of large amounts of ATP.

  2. Oxidation-reduction reactions.

  3. The use of multiple enzymes to catalyze reactions.

  4. An electron transport chain.

Show answer
Correct Option: A
Explanation:

Production of large amount of ATP takes place exclusively during respiration. However a small number of ATP is produced during the light reaction of photosynthesis, which is utilized for fixing or reducing CO$ _2$

So, the correct answer is 'The production of large amounts of ATP'

Which molecule is responsible for storing energy that can be used to do cellular work?

bio-chemistry carbohydrate metabolism energy output living organisms and energy production respiration in cell

  1. DNA

  2. Fat

  3. ATP

  4. Protein

Show answer
Correct Option: C
Explanation:

Energy derived from light or chemical compounds is stored in the form of ATP, it is a energy resource compound found across all organisms. Which can be hydrolyzed by the cell to derive energy for all its activities

So, the correct answer is 'ATP'

The enzyme ATP synthase is part of the process required to synthesize ATP from ADP and inorganic phosphate in the mitochondria.

Which of the following conditions would stimulate the synthesis of ATP?

bio-chemistry carbohydrate metabolism energy output living organisms and energy production respiration in cell

  1. A slowdown of glycolytic activity

  2. Elevated oxygen levels

  3. A build up of the proton gradient

  4. Decreased substrate-level phosphorylation in the cytoplasm

Show answer
Correct Option: C
Explanation:

A build up of proton gradient in the mitochondrial matrix is used by the ATP synthase to generate ATP from ADP and iP, this is also referred to as PMF or the free energy released by passive movement of protons from the mitochondrial matrix into the cytoplasm.

So, the correct answer is 'A build up of the proton gradient'

One molecule of NADH$ _{2}$ on oxidation yields ............... ATP molecules.

bio-chemistry carbohydrate metabolism energy output living organisms and energy production respiration in cell

  1. One

  2. Two

  3. Three

  4. Four

Show answer
Correct Option: C
Explanation:
The NADH$ _2$ and the FADH$ _2$ are produced during the cycles of respiration. These molecules are produced during the glycolysis and the Krebs cycle. These molecules are oxidized in the process of electron transport system. This is the system in which the electrons is donated from one donor to acceptor. These products are oxidized and the protons are used for creating a gradient which is used in the synthesis of ATP. NADH$ _2$ transfers the electrons to the complex I and then transfers the electrons to the complex II. This results in more number of protons which are pumped by ATP synthase. So, the more protons will result in the production of 3 ATPs.
Thus, the correct answer is option C. 

The amount of energy the earth receives from the sun per year is

bio-chemistry carbohydrate metabolism energy output living organisms and energy production respiration in cell

  1. $15 \times 100^{20} kcal$

  2. $10 \times 10^{30} kcal$

  3. $15 \times 10^{20} kcal$

  4. $15 \times 10^{25} kcal$

Show answer
Correct Option: C
Explanation:

The sun is considered as the major source of energy. The solar energy is the renewable form of energy and is used for various purposes like generating electricity, working of the solar batteries, etc. The total amount of the energy which is received by the earth from the sun is equal to about 15×10$^{20}$ kcal.

Thus, the correct answer is option C. 

The total amount of energy released from one molecule of glucose on oxidation is about 

bio-chemistry carbohydrate metabolism energy output living organisms and energy production respiration in cell

  1. $1600 kJ$

  2. $2300 kJ$

  3. $2500 kJ$

  4. $2900 kJ$

Show answer
Correct Option: D
Explanation:

The glucose molecule is oxidised to form pyruvic acid which is further oxidised to release water and carbon dioxide. When one glucose molecule is completely oxidised, 38 ATP molecules are formed. The energy of the 38 ATP is equal to about 2900 kJ or 686 kcal of energy. The equation of the glucose oxidation is given as 

C$ _6$ H$ _{12}$ O$ _6$ + 6O$ _2$ $\rightarrow$ 6CO$ _2$ + 6H$ _2$O + 2900 kJ energy
Thus, the correct answer is option D. 

How much of the energy released during aerobic respiration is approximately conserved in the form of ATP?

bio-chemistry carbohydrate metabolism energy output living organisms and energy production respiration in cell

  1. $20\%$

  2. $40\%$

  3. $60\%$

  4. $100\%$

Show answer
Correct Option: B
Explanation:

Aerobic respiration is a breakdown of organic material in the presence of oxygen. It takes place in the cytoplasm and mitochondria of the cell. During aerobic respiration, the first step is glycolysis in which there is a net formation of eight molecules of ATP and then the link reaction in which the pyruvic acid which is the end product of glycolysis is converted into acetyl CoA. 

This reaction leads to the formation of six molecules of ATP but these are not included in the Krebs cycle. This is acetyl CoA enter the Krebs cycle, which results in the formation of 30 molecules of ATP.
So, the net formation of ATP is 38 ATP and this round off to 40% of the total energy that is conserved as ATP.
So, the correct option is '40%'