Tag: bio-chemistry
Questions Related to bio-chemistry
Peroxisomes are commonly seen in
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Bundle sheath cells
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Vascular bundles
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Mesophyll cells
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Endopserm cells
Peroxisomes are present in the photosynthetic mesophyll cells of leaves. They play an important role in photorespiration. They maintain redox balance in cells and play a role in plant immune defence. Thus the correct answer is option C.
Which of the following is covered by a single membrane?
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Nucleus
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Mitochondria
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Plastids
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Sphaerosomes
- Sphaerosome is a cellular organelle enclosed by a single membrane which is only found in plant cells.
- It helps in storage and synthesis of lipid.
- They are formed from the endoplasmic reticulum.
- All the other cellular organelle nucleus, mitochondria and plastids are enclosed by a double membrane.
- So, the correct answer is 'Spherosomes'.
Enzymes associated with converting fats to carbohydrates are located in
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Liposomes
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Golgi bodies
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Glyoxysomes
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Microsomes
- Enzymes associated with converting fats to carbohydrates are located in 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 'Glyoxysomes'.
Glyoxysomes are connected with metabolism of
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Fats
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Proteins
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Carbohydrates
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All the above.
- 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 'Fats'.
The organelle present in germinating seeds and connected with $\beta$-oxidation or fat digestion is
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Glyoxysome
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Sphaerosome
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Peroxisome
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Mitochondrion
- The organelle present in germinating seeds and connected with β-oxidation or fat digestion is glyoxysome.
- 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 'Glyoxysome'.
Cell organelle covered by a single unit membrane is
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Glyoxysome
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Lysosome
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Peroxisome
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All of the above
- Unit membrane refers to the limiting membrane of cells and cellular organelles which is composed of 3-layered structure- an inner lipid layer and two outer protein layers.
- This unit membrane surrounds most of the cellular organelles (Golgi apparatus, glyoxysome, lysosomes, peroxisomes etc.).
- Lysosomes, glyoxysomes and peroxisomes are single-membraned cellular organelles.
- So, the correct answer is 'All of the above'.
What is not true of sphaerosomes?
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Single membrane covering
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Connected with fats
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Arise from endoplasmic reticulum
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Involved in photorespiration
- Spherosomes or oleosomes are small cellular organelles enclosed by a single membrane that is responsible for the storage and synthesis of lipid.
- They are obtained from the endoplasmic reticulum, they are surrounded by a single phospholipid monolayer and are found in only plant cells.
- So, the correct answer is 'Involved in photorespiration'.
Which organelle is present only in plants?
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Glyoxysome
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Lysosome
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Peroxisome
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Ribosome
- Glyoxysome is a type of peroxisome found in plants cells.
- It is mainly found in the cells of fat storing tissues of germinating seeds and is also present in filamentous fungi.
- The growing seed or the seedling utilizes the sugars synthesized from fats until it attains maturity (produce them by photosynthesis after maturity).
- So, the correct answer is 'Glyoxysome'.
In plant cells, peroxisomes are associated with
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Photorespiration
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Phototropism
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Photoperiodism
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Photosynthesis
- In plant cells, peroxisomes are associated with photorespiration.
- Peroxisomes (microbody) are small organelle which contains reducing and oxidising enzyme catalase.
- It helps in the breakdown of long chain fatty acids through beta-oxidation and converts them into to medium chain fatty acids, which are subsequently broken down to carbon dioxide and water in the mitochondria (photorespiration).
- So, the correct answer is 'Photorespiration'.
Out of peroxisomes, lysosomes and mitochondria, single membrane covering occurs in
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Both peroxisomes and lysosomes
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Only peroxisomes
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All of the above
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None of the above
- A lysosome is a single membrane-bound organelle which contains digestive enzymes that digest excess or worn out organelles, food particles, engulfed viruses or bacteria and macromolecules.
- The peroxisome is a single membrane-bound organelle which contains oxidative enzymes and is responsible for lipid production and oxidation reactions within the cell.
- Whereas, mitochondria is a double membrane-bound organelle and is known as the powerhouse of the cell which is present in all eukaryotic cells.
- So, the correct answer is 'Both peroxisomes and lysosomes'.