Tag: living organisms and energy production

Questions Related to living organisms and energy production

Which one does not contain DNA?

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

  1. Peroxisome

  2. Nucleus

  3. Chloroplast

  4. Mitochondria.

Show answer
Correct Option: A
Explanation:

Peroxisome  are surrounded by only a single membrane, and they do not contain DNA or ribosomes. Like mitochondria and chloroplasts, however, peroxisomes are thought to acquire their proteins by selective import from the cytosol. But because they have no genome, all of their proteins must be imported.


An oxidative organelle is

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

  1. Ribosome

  2. Golgi body

  3. Peroxisome

  4. ER

Show answer
Correct Option: C
Explanation:
  • The peroxisome is a single membrane-bound organelle which contains oxidative enzymes and is responsible for lipid production and oxidation reactions within the cell.
  • It helps in the oxidation of fatty acids, amino acids, purines and alcohol (liver cells) which requires significant amounts of oxygen.
  • So, the correct answer is 'Peroxisome'.

In which of the following would you expect to find glyoxysomes?

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

  1. Endosperm of wheat

  2. Endosperm of castor

  3. Palisade cell in leaf

  4. Root hairs

Show answer
Correct Option: B
Explanation:
  • The endosperm of castor (castor bean is oil producing plant)  contains glyoxysomes.
  • Glyoxysomes are a type of peroxisomes found in plants and few filamentous fungi.
  • They are particularly found in fat storage tissues of germinating seeds (peanuts, soybeans etc.) in plants.
  • They contain enzymes (citrate synthase, isocitrate lyase and malate synthase etc.) which are responsible for beta-oxidation of fatty acids,
  • It helps in fatty acid oxidation, glyoxylate cycle and gluconeogenesis.
  • So, the correct answer is 'Endosperm of castor'.

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

Show answer
Correct Option: C
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 germinating endosperm cells of oil seeds.
So, the correct answer is 'Glyoxysomes'.

_______ 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. Peroxisomers

  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 germinating endosperm cells of oil seeds.
So, the correct answer is 'Glyoxysomes'.

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 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 $H _{2}O _{2}$.
So, the correct answer is 'Take part in synthesis and storage of lipids'.

Which of the following statements regarding spherosomes 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 organelle extracted from endosperm of germinating castor beans are

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

  1. Glyoxysomes

  2. Vacuoles

  3. Mitochondria

  4. None of the above

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 germinating endosperm cells of oil seeds.
So, the correct answer is 'Glyoxysomes'.

All the following statements are correct, except

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

  1. Peroxisomes are quite common in the photosynthetic cells. Their number can be 70-100 per mesophyll cell, wherein they interact with mitochondria and chloroplasts to take part in photorespiration

  2. Glyoxysomes are numerous in the the endosperm of wheat.

  3. The ER-bound ribosomes synthesise secretory membrane and lysosomal protein

  4. Ribosomes when associated with ET are attached with their 60S sub-unit

Show answer
Correct Option: A
Explanation:

Peroxisomes are cytoplasmic organelles that play a central role in break down of fatty acids and other oxidation reactions in the cell.

So, the correct option is 'Peroxisomes are quite common in the photosynthetic cells. Their number can be 70-100 per mesophyll cell, wherein they interact with mitochondria and chloroplasts to take part in photorespiration'.

Which of the following organelle is associated with triglyceride metabolism?

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

  1. Peroxisome

  2. Glyxosome

  3. Sphaerosome

  4. Transosome

Show answer
Correct Option: A
Explanation:

 Peroxisomes are cell organelles that are involved in lipid or triglyceride metabolism. They are bound by a single membrane and are present in the cytosol.

So, the correct answer is 'Peroxisome'.