Tag: lipids

Questions Related to lipids

Select the wrong statement?

biology food and it's constituents functions and principal sources of lipids chemical organization in living beings lipids

  1. The protein part of the holoenzyme is called the apoenzyme

  2. Thylakoids are arranged one above the other like stack of coins forming a granum

  3. Building blocks of lipid are amino acids

  4. Cross-over occurs at pachytene stage of meiosis I

Show answer
Correct Option: C
Explanation:

Cofactor is a nonprotein part of the enzyme. It can be metal ions or the organic chemical. The cofactors which are organic chemicals are known as coenzyme. These are loosely attached to the apoenzyme. The tightly bound coenzymes are prosthetic group. 

Thylakoids are coin like structure present in the matrix of chloroplast which are stacked to form granum. 
Crossing over in meiosis helps in recombination by exchanging the segments between non homologous chromosomes.
Steroids are the organic molecule which plays an important role in the growth and development of the body. The molecular structure consists of 17 carbon which is arranged in four fused structure. It is found in plants, animals, and fungi. Steroids such as cholesterol form an integral component of the cell membrane and alter the membrane fluidity.
Lipids are nonpolar molecules so they are unable to interact with the polar molecule like water and thus they are insoluble in water. It is a hydrophobic molecule which is formed by ester linkage of the glycerol molecule with three fatty acid molecule. It does not consist amino acids. But the polymer of amino acids is protein.
So, the correct answer is option C.

Number of oxygen atoms in lipid molecules is always ......... as compared to number of carbon atoms

biology food and it's constituents functions and principal sources of lipids chemical organization in living beings lipids

  1. Less

  2. More

  3. Equal

  4. Double

Show answer
Correct Option: A
Explanation:
Lipid is formed by ester linkage of the glycerol molecule with three fatty acid molecules. The reaction by which the lipids are formed is known as dehydration. It is an important constituent of the cell membrane. It has the hydrophobic tail which does not interact with water. A lipid molecule has six oxygen and nine carbon atom. The carbon atom can vary depending on the R group attached to the fatty acid.
So, the correct answer is option A.

Which of the following lipid is essential part of good diet?

biology food and it's constituents functions and principal sources of lipids chemical organization in living beings lipids

  1. Oleic acid

  2. Linoleic acid

  3. Stearic acid

  4. Palmitic acid

Show answer
Correct Option: B
Explanation:
Essential fatty acids are that fatty acid which plays an important role in the biological process and they can be metabolized easily. These acts as a fuel rather getting deposited as fat in the body. The human body cannot synthesize essential fatty acids. Alpha-linolenic acid and linoleic acid are the two essential fatty acid. The essential fatty acids like alpha-linolenic acid and linoleic acid are unsaturated as they have double bonds.
So, the correct answer is option B.

Structural lipids of cell membrane are

biology food and it's constituents functions and principal sources of lipids chemical organization in living beings lipids

  1. Simple lipid

  2. Chromolipid

  3. Phospholipid

  4. Steroid

Show answer
Correct Option: C
Explanation:
Phospholipids are the structural lipids which have phosphorous attached to the lipids molecules. It is an important constituent of the cell membrane. It is made up of two hydrophobic fatty acid tails and a hydrophilic head consisting of a phosphate group. The two constituents are joined by a glycerol molecule. It can easily form bilayer because of its amphiphilic nature. It has the hydrophobic tail which does not interact with water and a hydrophilic head which can interact with water.
So, the correct answer is option C.

Which fatty acid is liquid at room temperature?

biology food and it's constituents functions and principal sources of lipids chemical organization in living beings lipids

  1. Palmitic acid

  2. Stearic acid

  3. Lauric acid

  4. Linoleic acid

Show answer
Correct Option: D

Steroids are

biology food and it's constituents functions and principal sources of lipids chemical organization in living beings lipids

  1. Lipids

  2. Proteins

  3. Vitamins

  4. Carbohydrates

Show answer
Correct Option: A
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 carbon which is arranged in four fused structure. It is found in plants, animals, and fungi. It is considered as an important class of lipids as they have properties similar to the triglycerides. It also plays important role in defensive mechanism of the body.

So, the correct answer is option A.

Cerebroside is a

biology food and it's constituents functions and principal sources of lipids chemical organization in living beings lipids

  1. Glycolipid

  2. Sterol

  3. Phospholipid

  4. Steroid

Show answer
Correct Option: A
Explanation:

Cerebroside is an important component of muscles and nerve cell membrane. It is also known as galactosylceramide. It is a class of glycolipids which consists of N -acyl sphingosine with glucose or galactose. Its deposition causes Gaucher disease. It is synthesized in endoplasmic reticulum and membranes of Golgi apparatus. It is degraded in the lysosomes. It is also known as galactolipid.

So, the correct answer is option A. 

Hydrolysis of lipid yields

biology food and it's constituents functions and principal sources of lipids chemical organization in living beings lipids

  1. Fats

  2. Fatty acids and glycerol

  3. Mannose and glycerol

  4. Maltose and fatty acid

Show answer
Correct Option: B
Explanation:

Most common lipids are triglycerides of glycerol and fatty acids. During digestion of lipids they are broken down into constituent fatty acids and glycerols by the action of lipase enzymes.

Hence B is the correct option. 

Choose the correct combination:

$a$ Fatty acid $1.$ Glutamic acid
$b$ Phospholipid $2.$ Tryptophan
$c$ Aromatic Amino Acid $3.$ Lecithin
$d$ Acidic Amino Acid $4.$ Palmitic acid
biology food and it's constituents functions and principal sources of lipids chemical organization in living beings lipids

  1. $a - 1, b - 2, c - 3, d - 4$

  2. $a - 4, b - 3, c - 2, d - 1$

  3. $a - 2, b - 3, c - 4, d - 1$

  4. $a - 3, b - 4, c - 1, d - 2$

Show answer
Correct Option: B
Explanation:

a) Palmitic acid is a saturated fatty acid. Its chemical formula is CH$ _3$(CH$ _2$)$ _{14}$COOH. Meat, cheese and diary products are the main source of the palmitic acid. It was first discovered in saponified palm oil. Excess carbohydrate in the body is converted into palmitic acid. 

b) Lecithin is an essential phospholipid which is present in the body. It is composed of choline, fatty acids, glycerol, glycolipids, phospholipids, phosphoric acid and triglycerides.
c) Tryptophan is a aromatic amino acid which acts as a precursor to the neurotransmitter. It helps in biosynthesis of proteins. It also helps in the synthesis of niacin and auxin.
d) Glutamic acid is an acidic amino acid which acts as a important neurotransmitter.
So, the correct answer is option B.

Commonly, candles are prepared from

biology food and it's constituents functions and principal sources of lipids chemical organization in living beings lipids

  1. Bees wax

  2. Paraffin wax

  3. Stearic acid

  4. Both (b) and (c)

Show answer
Correct Option: D
Explanation:

The use of wax used to prepare candles has changed during the past few centuries. Nowadays, standard commercial candles are made from a combination of Paraffin wax and Stearic acid. A small amount of Bee wax may or may not be added in the making.