Tag: cell membrane

Questions Related to cell membrane

Multiple choice bio-chemistry lipids derived lipids biomolecules: chemical constituents of living cells cell membrane

Beta-oxidation mainly takes place in _________.

  1. Cytoplasm

  2. Mitochondria

  3. Golgi bodies

  4. None of the above

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

In biochemistry and metabolism, beta-oxidation is the catabolic process by which fatty acid molecules are broken down in the cytosol in prokaryotes and in the mitochondria in eukaryotes to generate acetyl-CoA, which enters the citric acid cycle, and NADH and FADH2, which are co-enzymes used in the electron transport.

Multiple choice bio-chemistry lipids derived lipids biomolecules: chemical constituents of living cells cell membrane

Which among the following is the anabolic process?

  1. Glucose converts to lactic acid.

  2. Acetic acid is converted to cholesterol

  3. Glucose converted to pyruvic acid

  4. Glycogen converted to glucose

Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Anabolic process involves the synthesis of complex molecules from simple molecules. Cholesterol is a large and complicated molecule. The starting point of cholesterol synthesis is acetic acid.
So, the correct option is 'Acetic acid is converted to cholesterol'
Multiple choice bio-chemistry lipids derived lipids biomolecules: chemical constituents of living cells cell membrane

Steroid is derived from

  1. Cholesterol

  2. Thyroxine

  3. Vitamin A

  4. Fatty acid ester

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Steroids are the organic molecule which plays an important role in the growth and development of the body. The molecular structure consists of 17 carbons which are arranged in four fused structure. It is found in plants, animals and fungi. Cholesterol which is the derivative of steroid forms an integral component of the cell membrane and alter the membrane fluidity. The also acts as hormone precursor for steroidal hormones.
So, the correct answer is option A.
Multiple choice bio-chemistry lipids derived lipids biomolecules: chemical constituents of living cells cell membrane

Misuse of anabolic steroids cause various side-effects in males and females. Which  of the following  side-effects of anabolic steroids is not observed in females?

  1. Masculinisation

  2. Breast enlargement

  3. Excessive hair growth on face and body

  4. Deepening of voice

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Masculinisation is a side-effect which is not commonly observed in females due to the intake of anabolic steroids. so, 'the correct option is - masculinisation'. "So, the correct answer is 'A' ".

Multiple choice bio-chemistry lipids derived lipids biomolecules: chemical constituents of living cells cell membrane

Which of the following is a major substrate for synthesis of fats?

  1. Acetyl- CoA

  2. Pyruvate

  3. Glycogen

  4. None of the above

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Fatty acids are components of the phospholipids that make up the bulk of the lipid bilayers of all cellular membranes. It is synthesized by cytosolic acetyl-CoA  through carboxylation by acetyl-CoA carboxylase into malonyl CoA. This conversion occurs primarily in the liver, adipose tissue and lactating mammary glands, where the fatty acids are combined with glycerol to form triglycerides

So, the correct answer is option A.

Multiple choice bio-chemistry lipids derived lipids biomolecules: chemical constituents of living cells cell membrane

Stability of the plasma membrane is enhanced by _________ .

  1. cholesterol molecules

  2. phospholipids

  3. glycoproteins

  4. glycolipids

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Cholesterol helps to keep the membrane stable. This stability is maintained  as: At high temperatures, cholesterol reduces membrane fluidity by restraining the movement of phospholipids. At low temperatures, cholesterol gives solidification of the membrane because it prevents the close packing of phospholipids.

So, the correct answer is 'cholesterol molecules'

Multiple choice bio-chemistry lipids derived lipids biomolecules: chemical constituents of living cells cell membrane

Heterotrophs can metabolize lipids by a process called ___________ into monomers of _____________ and fatty acids.

  1. Hydrolysis; Glycerol

  2. Dehydration synthesis; Glycerol

  3. Hydrolysis; Glycolipids

  4. Dehydration synthesis; Glycolipids

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Heterotrophs can metabolize lipids by a process of hydrolysis, where water molecule is added to break down a chemical compound (lipids). 

Lipids on hydrolysis yield fatty acids and glycerol
So, the correct answer is 'Hydrolysis; Glycerol'

Multiple choice bio-chemistry lipids derived lipids biomolecules: chemical constituents of living cells cell membrane

Animal membranes contain

  1. Steroids

  2. Chlorophyll

  3. Prostaglandins

  4. Vitamin A

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
Steroids are the organic molecule which plays an important role in the growth and development of the body. It is a four-ring structure. Steroids such as cholesterol form an integral component of the cell membrane and alter the membrane fluidity. It provides the stability to the cell membrane by limiting the membrane fluidity. 
So, the correct answer is option A.
Multiple choice bio-chemistry lipids derived lipids biomolecules: chemical constituents of living cells cell membrane

Saturated fatty acid that reduces oil quality is

  1. Palmitic acid

  2. Stearic acid

  3. Erucic acid

  4. All the above.

Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Fatty Acid Composition of Canola Oil The decrease in the level of erucic acid in rapeseed oil resulted in a marked increase in C18 acids, which make up approximately 95% of all fatty acids present in canola oil. 

Hence C is the correct answer.