Tag: some biomolecules

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Questions Related to some biomolecules

Multiple choice bio-chemistry biological molecule lipids and their function some biomolecules lipids

Essential fatty acids are

  1. Arachidonic acid

  2. Linolenic

  3. Linoleic acid

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
  • Animals that cannot synthesize fatty acids in the body de novo are called as an essential fatty acid. These (arachidonic acid, linolenic, linoleic acid) are polyunsaturated fatty acids essential for growth and health but are not synthesized in the animal body. 
  • Linoleic acid is abundant in corn, peanut, cottonseed and soyabean oil and gives rise to other two in the body.
  • The deficiency of these fatty acids causes sterility, kidney failure, and skin lesions.
Multiple choice bio-chemistry biological molecule lipids and their function some biomolecules lipids

Neutral fat are

  1. Glycerol

  2. Fatty acids

  3. Both A and B

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Triglycerides or neutral fats or true fats are the esters of three molecules of fatty acids and one molecule of trihydric alcohol glycerol. Hence, they are also called triglycerides. Oils are liquid at room temperature. They possess either small or unsaturated fatty acid.

Multiple choice bio-chemistry biological molecule lipids and their function some biomolecules lipids

What are glycerides of fatty acids?

  1. Lecithin

  2. Phospholipids of plasma membrane

  3. Vegetable oils

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Glyceride denotes a fatty ester of glycerol. The term is usually used in combination with phospho- (phosphoglyceride). The use of mono-, di-, and triglyceride is being replaced by the more precise terms mono-, di-, and triacylglycerol, respectively. 
Lecithin is any of a group of phospholipids that on hydrolysis yield two fatty acid  molecules and a molecule each of glycero-phosphoric  acid and choline. They are found in nervous tissue, especially myelin sheaths and egg yolk, and in the plasma membrane of plant and animal cells.
Vegetable oils are the oils and fats obtained from plants.
Multiple choice bio-chemistry biological molecule lipids and their function some biomolecules lipids

Which of the following fatty acid is not synthesized in the human body?

  1. Glycerol

  2. Cholesterol

  3. Linoleic acid

  4. Both A and B
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Linoleic acid (LA) is an essential fatty acid but is not synthesized in the human body. LA is a polyunsaturated fatty acid used in the biosynthesis of arachidonic acid (AA) and thus some prostaglandins, leukotrienes (LTA, LTB, LTC), and thromboxane (TXA). It is found in the lipids of cell membranes. It is abundant in many vegetable oils, comprising over half of poppy seed, safflower, sunflower, corn, and soybean oils.

Multiple choice bio-chemistry biological molecule lipids and their function some biomolecules lipids

Wax is ester of fatty acid with

  1. Long chain dihydric alcohol

  2. Trihydric alcohol

  3. Long chain monohydric alcohol

  4. Short chain monohydric alcohol
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Wax is ester of fatty acids with long chain monhydric alcohol. Cholesterol is the type of alcohol found in wax. It is not easily hydrolyzed like fat. It gives protection. It prevents excessive drying. It also provides water resistance. Beeswax, carnuba wax are examples of wax.

Thus, the correct answer is option C.

Multiple choice bio-chemistry biological molecule lipids and their function some biomolecules lipids

A saturated fatty acid is

  1. With no double bond

  2. High melting point

  3. Low melting point

  4. Both A and B
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Saturated fatty acids are the fats that do not contain a double bond between the carbon atoms. Fatty acids chain are straight. Saturated fats are mostly found in animal fats and animal product. It is solid at room temperature e.g., butter. Saturated fatty acids are high melting than unsaturated fatty acids(low melting point and liquid at room temperature). Thus, the correct option is D.

Multiple choice bio-chemistry biological molecule lipids and their function some biomolecules lipids

The melting point of unsaturated fatty acids

  1. Increases with increase in double bonds

  2. Decreases with increase in double bonds

  3. Rises in some and falls in others

  4. There is no relationship between unsaturation and melting point
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Unsaturated fats are liquid at room temperature as they have double bonds. Saturated fatty acids have the single bond and are solid at room temperature. Hydrogenation is the process which involves the addition of hydrogen in the presence of nickel, palladium or platinum. On addition of hydrogen, the double bonds of fatty acids are reduced. 

The unsaturated fats have the low melting point as they the double bond has the cis configuration which causes weak intermolecular interactions. With the increase in the double bond, the intermolecular interaction gets weak and the melting point decreases.
So, the correct answer is option B.

Multiple choice bio-chemistry biological molecule lipids and their function some biomolecules lipids

Number of double bonds present in arachidonic acid is

  1. $4$
  2. $3$
  3. $2$
  4. $1$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Arachidonic acid is a carboxylic acid which has 20 carbon and four double bonds in the cis configuration. It is a polyunsaturated fatty acid (PUFA). It is mainly present in the membrane phospholipids and in platelets. It is also found in liver, erythrocytes, skeletal muscle, cardiac muscle. Meat, egg, and fish are rich sources of arachidonic acid.

Thus, the correct answer is option A.

Multiple choice bio-chemistry biological molecule lipids and their function some biomolecules lipids

Essential fatty acids occur in

  1. Animal fat

  2. Plant oils

  3. Fish and fowl

  4. Both B and C
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Essential fatty acids are those fatty acids that body cannot produce on its own and therefore must be supplied from the diet. Two primary essential fatty acids are linoleic acid and alpha-linoleic acid. Linoleic acid (omega-6) occurs in plant oils like corn oil, palm oil, soybean oil, sunflower oil. Alpha-linoleic acid (omega-3) occurs in fowl and fish like salmon, sardines, tuna.

Thus, the correct answer is option D.