Tag: living organisms and energy production

Questions Related to living organisms and energy production

The function of glyoxysome is

bio-chemistry structure and function of cell organelles microbodies living organisms and energy production single membrane bound organelles

  1. Protein metabolism

  2. Carbohydrate metabolism

  3. Fat metabolism

  4. Protein synthesis

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Correct Option: C

Which of the following statements regarding sphaerosomes is not correct?

bio-chemistry structure and function of cell organelles microbodies living organisms and energy production single membrane bound organelles

  1. Abundant in the endosperm cells of oil seeds

  2. Bounded by a single membrane

  3. Take part in synthesis and storage of lipids

  4. Take part in photorespiration

Show answer
Correct Option: D
Explanation:

Sphaerosomes are small cell organelles bounded by single membrane which take part in storage and synthesis of lipids. Sphaerosomes occur abundantly in the endosperm cells of oil seeds. Sphaerosomes of some tissues (e.g., tobacco endosperm, maize root tip) contain hydrolytic enzymes. Therefore, they are considered to have lysosomic activity. They donot take part in photorespiration.
So, the correct answer is 'Take part in photorespiration'.

Cell organelles taking part in photorespiration are ____________.

bio-chemistry structure and function of cell organelles microbodies living organisms and energy production single membrane bound organelles

  1. Peroxisomes

  2. Glyoxisomes

  3. Dictysomes

  4. Endoplasmic reticulum

Show answer
Correct Option: A
Explanation:

Peroxisomes are membrane-bound organelles in eukaryotes. Photorespiration is a light-dependent process that takes place in mitochondria in which oxygen is absorbed and carbon dioxide is released. It is counter-productive to photosynthetic carbon dioxide fixation and decreases plant productivity. But it also provides protection against conditions caused by high light intensity, drought, and salinity.  Thus the correct answer is option A.

Read the given statements and select the correct option.


Statement 1: Peroxisomes are involved in photorespiration of the plant cells and help in the lipid metabolism of animal cells.
Statement 2: They are the cell's garbage disposal system.

bio-chemistry structure and function of cell organelles microbodies living organisms and energy production single membrane bound organelles

  1. Both statements 1 and 2 are correct

  2. Statement 1 is correct but statement 2 is incorrect

  3. Statement 2 is correct but statement 2 is incorrect

  4. Both statements 1 and 2 are incorrect

Show answer
Correct Option: B
Explanation:

Peroxisomes are found in photosynthetic cells and perform photorespiration. They also take part in lipid metabolism. Lysosomes are the cell's garbage disposal system and not the peroxisomes.

So, Statement 1 is correct and statement 2 is incorrect.

Glycolate cycle occurs in?

bio-chemistry structure and function of cell organelles microbodies living organisms and energy production single membrane bound organelles

  1. Lysosomes

  2. Ribosomes

  3. Glyoxysomes

  4. Peroxisomes

Show answer
Correct Option: C
Explanation:
In plants, the glyoxylate cycle occurs in specialized cells called glyoxysomes. During germination, the seeds used lipids as the energy source to form the shoot. Acetyl CoA proceeds through glyoxylate cycle and released succinate as the end product. This cycle occurs only in glyoxysomes, which are lying in the fat storage tissues of germinating seeds. 

Hence, the correct answer is option C.

Which one of these is not correct regarding peroxisomes?

bio-chemistry structure and function of cell organelles microbodies living organisms and energy production single membrane bound organelles

  1. Single membrane bound organelles

  2. Perform photorespiration in ${C} _{3}$ plants

  3. Take part in synthesis and storage of lipids

  4. Protect a cell from the toxic effects of ${H} _{2}{O} _{2}$

Show answer
Correct Option: C
Explanation:
SER takes part in the synthesis and storage of lipids. Peroxisomes are the single membrane bound cell organelles, which perform photorespiration in association with chloroplasts and mitochondria. They protect the cell from the toxic effects of $H2 _O$. 
So, the correct answer is 'Take part in the synthesis and storage of lipids'.

_______ are the microbodies, which take part in glyoxylate pathway, bounded by a single membrane and are usually present in germinating fatty seeds.

bio-chemistry structure and function of cell organelles microbodies living organisms and energy production single membrane bound organelles

  1. Glyoxysomes

  2. Peroxisomes

  3. Sphaerosomes

  4. Lysosomes

Show answer
Correct Option: A
Explanation:

Glyoxysomes are microbodies which contain enzymes for $\beta$-oxidation of fatty acids and glyoxylate pathway. They are considered to be special peroxisomes. They occur abundantly in gerrminating endosperm cells of oil seeds.

Chemiosmosis hypothesis given by Peter Mitchell proposes the mechanism of

bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

  1. Synthesis of NADH.

  2. Synthesis of ATP.

  3. Synthesis of FADH$ _2$.

  4. Synthesis of NADPH.

Show answer
Correct Option: B
Explanation:
Chemiosmosis or chemiosmotic theory is given by Peter Mitchell explains the synthesis of ATP in the chloroplast. During the process of photosynthesis, the synthesis of ATP causes proton gradient to develop due to the accumulation of protons in thylakoid lumen that are formed by splitting of water. As the electron moves through the photosystem, protons are transported across the membrane. Now NADP reductase (enzyme) in stroma along with the electron acceptor removes protons along with the reduction of NADPH + H+. This causes proton gradient across the thylakoid membrane. The ATPase enzyme has a channel which allows the flow of proton through it and during this process the ATP is synthesised. Thus the correct answer is option B.

Riboflavin is essential in our diet, as it is required for the synthesis of

bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

  1. TPP

  2. COASH

  3. NAD

  4. FAD

Show answer
Correct Option: D

Major function of respiration is to produce

bio-chemistry biological oxidation oxidative phosphorylation living organisms and energy production glycolysis

  1. NADH $(H^+)$

  2. ATP

  3. Pyruvate

  4. $C _2H _5OH$

Show answer
Correct Option: B
Explanation:

Respiration is a process in which respiratory substrates are broken down through oxidation accompanying with the release of energy and its storage or conservation in the form of ATP with the release of carbon dioxide as a consequence. The actual mechanism of respiration is a stepwise process in which each step is catalyzed by a specific enzyme and the energy stored in the substrate is released in a stepwise series of reactions. The energy released in the process is used up in various energy-requiring processes of organisms. 

Thus, the correct answer is option B.