Tag: single membrane bound organelles

Questions Related to single membrane bound organelles

Urate oxidase occurs in

  1. Lomasomes

  2. Peroxisomes

  3. Mitochondria

  4. Glyoxysomes


Correct Option: B
Explanation:

Peroxisomes are microbodies which have enzymes for peroxide metabolism. They include :
(a) Peroxide producing oxidative enzymes like peroxidase, urate oxidase or uricase, amino acid oxidase.
(b) Peroxide destroying enzymes like catalase. 

The function of peroxisome is  

  1. H$ _2$O$ _2$ destruction

  2. Conversion of fats to carbohydrates

  3. Detoxification of heavy metals

  4. Oxidative phosphorylation


Correct Option: A
Explanation:

Peroxisomes are single membrane covered cell organelles which take part in oxidation reactions other than those of respiration. Peroxisomes are microbodies which have enzymes for peroxide biosynthesis like peroxidases, amino acid oxidase and peroxide destruction like catalase.

What is degraded by peroxisomes?

  1. Carbon dioxide

  2. Hydrogen peroxide

  3. Lithium oxide

  4. Carbon monoxide


Correct Option: B
Explanation:

Peroxisomes are microbodies which have enzymes for peroxide metabolism. They include : (a) Peroxide producing oxidative enzymes like peroxidase, urate oxidase or uricase, amino acid oxidase and (b) peroxide destroying enzymes like catalase.
Peroxisomes occur widely in animals cells, protists, fungi, higher plants but quite common in photosynthetic cells. In mesophyll cells, peroxisomes interact with chloroplasts, and mitochondria to take part in photorespiration.

Peroxisomes, in plant cells, are involved in

  1. Photooxidation

  2. Photorespiration

  3. Photophosphorylation

  4. Photolysis of water


Correct Option: B
Explanation:
Peroxisomes are microbodies which have enzymes for peroxide metabolism. They include :
(a) Peroxide producing oxidative enzymes like peroxidase, urate oxidase or uricase, amino acid oxidase and (b) Peroxide destroying enzymes like catalase.
Peroxisomes occur widely in animals cells, protists, fungi, higher plants but quite common in photosynthetic cells. In mesophyll cells, peroxisomes interact with chloroplasts, and mitochondria to take part in photorespiration.

DNA remains absent in

  1. Chloroplast

  2. Nucleus

  3. Peroxisomes

  4. Chromosomes


Correct Option: C
Explanation:

Peroxisomes are microbodies which have enzymes for peroxide metabolism. They include :

(a) Peroxide producing oxidative enzymes like peroxidase, urate oxidase or uricase, amino acid oxidase and (b) Peroxide destroying enzymes like catalase. 
Peroxisomes do not have DNA. DNA is present in nucleus and some cell organelles like chloroplast and mitochondria.

Microbodies are minute vesicles and are present in

  1. Plant cells only

  2. Animal cells only

  3. Prokaryotic cells only

  4. Both plant and animal cells


Correct Option: D
Explanation:
Microbodies are a type of organelles that are found in both plant and animal cells. The organelles in the microbody family include peroxisomes, glyoxysomes, glycosomes and hydrogenosomes. In vertebrates, microbodies are especially prevalent in the liver and kidney organs.
So, the correct answer is 'Both plant and animal cells'.

Glyoxysomes occur in

  1. Both plant and animal cells

  2. Plant cells only

  3. Animal cells only

  4. All types of cells


Correct Option: B
Explanation:

Glyoxysomes are microbodies which occur only in fat rich plant cell, where they take part in $\beta$-oxidation of fats and perform glyoxylate cycle. 

Glyoxysomes are useful in

  1. Converting sugars to fats

  2. Converting fats to sugars

  3. Deamination and converting amino acids to fatty acids

  4. Amination and changing fatty acids to amino acids


Correct Option: B
Explanation:
  • 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.
  • It helps in fatty acid oxidation, glyoxylate cycle and gluconeogenesis.
  • They contain enzymes (citrate synthase, isocitrate lyase and malate synthase etc.) which are responsible for beta-oxidation of fatty.
  • It also contains enzymes which produce intermediate products for the synthesis of sugars by gluconeogenesis.
  • So, the correct answer is 'Converting fats to sugars'.

Some of the enzymes, which are associated in converting fats into carbohydrates, are present in

  1. Liposomes

  2. Golgi bodies

  3. Microsome

  4. Glyoxysomes


Correct Option: D
Explanation:

Glyoxysomes are microbodies which occur only in fat rich plant cell, where they take part in $\beta$-oxidation of fats and perform glyoxylate cycle. Glyoxysomes also possess catalase enzyme. In fat storing plant cells, first fats are converted to carbohydrates which are then metabolised.

In 1967, R. W. Breidenbach and H. Beevers discovered microbodies in fat storing cells of germinating seed known as

  1. Lomasomes

  2. Mesosomes

  3. Peroxisomes

  4. Glyoxysomes


Correct Option: D
Explanation:

Glyoxysomes were discovered by Breidenbach, 1967 and Beevers, 1963. Glyoxysomes are microbodies which occur only in fat rich plant cells where they take part in $\beta$-oxidation of fats and perform glycolate cycle. Glyoxysomes possess catalase enzyme.