Tag: biomolecules: chemical constituents of living cells

Questions Related to biomolecules: chemical constituents of living cells

Which tissue is responsible for providing insulation to the body?

bio-chemistry lipids functions of lipids biomolecules: chemical constituents of living cells biochemistry

  1. Epithelial tissue

  2. Adipose tissue

  3. Fibrous connective tissue

  4. Nervous tissue

  5. Muscle tissue

Show answer
Correct Option: B
Explanation:

Adipose tissue, or fat, is an anatomical term for loose connective tissue composed of adipocytes. Its main role is to store energy in the form of fat, although it also cushions and insulates the body.

The greatest amount of energy per gram is produced by

bio-chemistry lipids functions of lipids biomolecules: chemical constituents of living cells biochemistry

  1. Sugar

  2. Starch

  3. Fat

  4. Proteins

  5. Vitamins

Show answer
Correct Option: C
Explanation:
Our food contains three main constituents: carbohydrates, fats and proteins. The amount of energy released when one gram of any of these food elements is burned is known as calorific value. Thus calorific value of food indicates as to how much is the energy value of food which the human body can gain through metabolism. It is usually given in kcal/gm. Fats form the most concentrated source of energy in our diet. 1 gram of fat yields 9.5 kcal of energy which is the highest among the food components. 1 gram of carbohydrates and proteins yield almost similar amount of energy which is equal to 4 kcal.
Thus, the correct answer is option C.

Which is used for staining lipids?

bio-chemistry lipids functions of lipids biomolecules: chemical constituents of living cells biochemistry

  1. Rhodamine

  2. Iodine

  3. Ethidium bromide

  4. Sudan Red

Show answer
Correct Option: D
Explanation:

 Lipids are the compound formed by alcohol and fatty acids ester linkage. They are characterized by solubility in the organic solvent. Sudan Red dye is used to stain lipids. It is water insoluble but dissolves with fats. Therefore, dye accumulates in the globules within the cells. Thus, the correct option is  D.

Study the given statement and select the correct answer  

bio-chemistry lipids functions of lipids biomolecules: chemical constituents of living cells biochemistry

  1. Lipids are micromolecules but obtained under-macromolecular fraction due to their insoluble nature in aquous medium of a cell.

  2. water is the most aboundant chemical in living organism

  3. First respiratory substrate = Lipid

  4. DIhydroxy acetone occur in d and I form.

Show answer
Correct Option: A

Identify the statement which is incorrect about absorption of lipids.

bio-chemistry lipids functions of lipids biomolecules: chemical constituents of living cells biochemistry

  1. The lipids are absorbed in laymp capillaries present with the villi

  2. From the micelles ,fatty acids and glycerol are absorbed into the intestinal cells by active transport

  3. Micelles are formed with the help of bile salts and phospholipids in intestinal lumen

  4. The lacteals after absorption of lipids contains chyle

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Correct Option: A

Biological function of lipids is/are

bio-chemistry lipids functions of lipids biomolecules: chemical constituents of living cells biochemistry

  1. Source of energy

  2. Insulating material

  3. Maintenance of cellular integrity with other macromolecules

  4. All of the above

Show answer
Correct Option: D
Explanation:

Fats are an important class of biomolecules.They are compounds of carbon, hydrogen and oxygen where the ratio of hydrogen and oxygen is less than that of water. Lipids are a concentrated source of energy and serve for long term energy storage in body of animals and plants. Their respiratory quotient is less than one. Approximately 9 calories are provided by one gram of fat as compared to 4 by carbohydrates. Fats also act as insulating material because they are poor conductors of heat. Most of the animals have a layer of fat below the skin acting as insulating material. Lipids also serve as structural biomolecules for example conjugate lipid molecules like phospholipids, glycolipids, sphingolipids etc.

........... prevents the rupturing of lysosomal membrane.

bio-chemistry lipids functions of lipids biomolecules: chemical constituents of living cells biochemistry

  1. Cholesterol

  2. Vit. A

  3. Testosterone

  4. UV rays

Show answer
Correct Option: A
Explanation:

Vitamin A, testosterone and UV rays induce lysis of lysosomal membrane under acidic pH which makes options B, C and D incorrect. Cholesterol exhibit scavenging effect on free radicals as well as prevent osmotic rupture of lysosomal membrane which makes option A correct answer. 

Which of the following molecular form is stored energy in animals?

I. Glucose

II. Glycogen

III. Lipid

IV. Protein

bio-chemistry lipids functions of lipids biomolecules: chemical constituents of living cells biochemistry

  1. I and II

  2. II and III

  3. I, II and III

  4. II, III and III

  5. I, II, III and IV

Show answer
Correct Option: B
Explanation:

Glycogen is a polysaccharide that serves as a form of stored energy  in animals and fungi. Excess glucose is polymerised and stored as glycogen in the liver of animals and starch in plants. Excess of fatty acid is converted to lipids. Adipose tissue stores lipids in the form of “triglycerides”.
Thus, the correct answer is option "II and III". 

The energy storing molecules in animals are
I. Glucose
II. Glycogen
III. Lipid
IV. Protein

bio-chemistry lipids functions of lipids biomolecules: chemical constituents of living cells biochemistry

  1. I and II

  2. II and III

  3. I, II and III

  4. II, III and IV

  5. I, II, III and Iv

Show answer
Correct Option: B
Explanation:

Glycogen is also homopolysaccharide of D-glucose and serves as an energy storing molecule in animals as glucose as storage material can increase the osmotic pressure of storage cell enormously. Proteins do not serve as energy storage molecule. Fat and oil are storage lipids and are derivatives of hydrocarbon that produce enormous energy upon oxidation. Thus, the correct answer is B.

Which of the following is the function of lipids?

bio-chemistry lipids functions of lipids biomolecules: chemical constituents of living cells biochemistry

  1. Regulation of membrane permeability

  2. Regulation of fluidity of membranes

  3. Electrical insulation to nerve fibre

  4. All of the above

Show answer
Correct Option: D
Explanation:

Lipids are broken down in the digestive tract to form fatty acids and cholesterol. Fatty acids and cholesterol are key components of cell membranes that regulate its fluidity and permeability. Lipids of the nervous system are localized in myelin sheaths thereby providing electrical insulation. Thus the correct answer is option D.