Test: Respiration in Plants - Overview (July 3) - NEET MCQ

Plants require a number of mineral elements for optimum growth and activity. Phosphorous is an essential macro nutrient. It is a component of energy rich nucleotides, like ATP, GTP etc. 
Phosphorous participates in all the reactions, where energy is either evolved or consumed. Hence, phosphorous plays an indispensable role in energy metabolism of a cell.

Respiration is the process by which living organisms take in oxygen and release carbon dioxide. It is essential for the production of energy in the form of ATP (adenosine triphosphate).
The source of respiration is not mentioned in the given options, but we can determine the correct answer by process of elimination:
A: Stored food - This is not the source of respiration. While food is broken down during respiration, it is not the initial source of oxygen for the process.
B: RNA - RNA (ribonucleic acid) is involved in protein synthesis, but it is not the source of respiration.
C: DNA - DNA (deoxyribonucleic acid) contains genetic information, but it is not directly involved in respiration.
D: ATP - While ATP is an important molecule in respiration, it is not the source of respiration itself.
Therefore, none of the given options are the correct source of respiration. It is important to note that the correct answer is not provided in the options, and the correct source of respiration is oxygen from the air. Oxygen is obtained through breathing and is used in cellular respiration to produce ATP.

B is right becz when one pyruvic acid convert into acetyl co-A then one NADH2 produced, from which 3 ATP produced through ETS.

Explanation:
Aerobic Respiration:
- Aerobic respiration is the process by which glucose is broken down in the presence of oxygen to produce energy.
- It is the most efficient way to produce energy in living organisms.
- Glucose is completely oxidized to produce carbon dioxide, water, and energy in the form of ATP.
Energy Yield:
- In aerobic respiration, one molecule of glucose produces a total of 38 ATP molecules.
- Each ATP molecule carries about 7.3 kilocalories (K.cal) of energy.
- Therefore, the total energy produced in aerobic respiration can be calculated by multiplying the number of ATP molecules with the energy content of each ATP molecule.
Calculation:
- 1 molecule of glucose produces 38 ATP molecules.
- 38 ATP molecules * 7.3 K.cal/ATP = 277.4 K.cal
Answer:
- The correct answer is C: 686 K.cal.

Breakdown of carbohydrates (glucose) takes place in the body by glycolysis followed by tricarboxylic acid cycle (Kreb's cycle) resulting in the energy in the form of ATP. Glucose can alternatively also undergo a different pathway to produce other products required by the cells. One of these alternate pathways is the pentose phosphate pathway or also called as hexose monophosphate pathway in which oxidation of glucose 6-phosphate takes place to produce pentoses. The fate of glucose whether to undergo glycolysis or the hexose monophosphate pathway is decided by the relative concentrations of NADP+ and NADPH. The phase starts with the oxidation of glucose 6-phosphate by the enzyme glucose 6-phosphate dehydrogenase to yield 6-phosphogluconolactone. This enzyme is an NADP dependent enzyme, where NADP+accepts an electron to form NADPH + H+.

Hexose monophosphate shunt is a secondary pathway for the metabolism of glucose in tissues other than skeletal muscles, in which five-carbon sugars are synthesized and NADPH is produced with the loss of CO₂ in the cytoplasm outside the mitochondria, whereas there is no CO₂ production in glycolysis.

Link between carbohydrate and fat metabolism:
1. Acetyl Co-A:
- Acetyl Co-A is a molecule that plays a central role in both carbohydrate and fat metabolism.
- In carbohydrate metabolism, glucose is broken down through glycolysis to produce pyruvic acid.
- Pyruvic acid is then converted into acetyl Co-A, which enters the citric acid cycle (also known as the Krebs cycle or TCA cycle).
- In the citric acid cycle, acetyl Co-A is further metabolized to produce ATP, CO2, and high-energy electron carriers (NADH and FADH2).
- Acetyl Co-A can also be used to synthesize fatty acids, which are then stored as triglycerides in adipose tissue.
2. Citric acid cycle:
- The citric acid cycle is a series of chemical reactions that occurs in the mitochondria of cells.
- It is a central pathway in cellular respiration and plays a key role in the metabolism of carbohydrates, fats, and proteins.
- Acetyl Co-A enters the citric acid cycle and undergoes a series of enzymatic reactions, leading to the production of ATP, CO2, and high-energy electron carriers.
- The CO2 produced during the citric acid cycle is a byproduct of carbohydrate metabolism.
3. CO2:
- CO2 is produced during the citric acid cycle as a result of the metabolism of carbohydrates.
- It is an important waste product that is exhaled from the body during respiration.
- Although CO2 is not directly involved in fat metabolism, it is an indirect link between carbohydrate and fat metabolism as it is produced during the breakdown of carbohydrates in the citric acid cycle.
Therefore, the correct answer is B: Acetyl Co-A, as it is a molecule that connects carbohydrate and fat metabolism by entering the citric acid cycle and being involved in the synthesis of fatty acids.

Nicotinamide adenine dinucleotide phosphate, abbreviated NADP⁺ or, in older notation, TPN, is a cofactor used in anabolic reactions, such as lipid and nucleic acid synthesis, which require NADPH as a reducing agent. It is the coenzyme - II

The end product of glycolysis is pyruvic acid.
Glycolysis is the metabolic pathway that converts glucose into pyruvate. It occurs in the cytoplasm of the cell and it is the first step in both aerobic and anaerobic respiration. Here is a breakdown of the process and the end product:
1. Glucose breakdown:
- Glucose, a 6-carbon sugar, is broken down into two 3-carbon molecules called glyceraldehyde-3-phosphate (G3P).
2. Energy production:
- During the steps of glycolysis, two molecules of ATP (adenosine triphosphate) are used to prime the glucose molecule. Through a series of enzymatic reactions, four molecules of ATP are produced, resulting in a net gain of two ATP molecules.
3. Pyruvate formation:
- The final step of glycolysis involves the conversion of G3P into pyruvate. Each G3P molecule is converted into pyruvate, resulting in the production of two pyruvate molecules.
Therefore, the end product of glycolysis is pyruvic acid (pyruvate).

The breakdown of the simple sugar i.e. glucose in glycolysis provides the first 6- carbon molecule required for the pentose phosphate pathway. During the first step of glycolysis, glucose is transformed by the addition of a phosphate group, generating glucose-6-phosphate another 6- carbon molecule.