Tag: lipids

Questions Related to lipids

A product of glycerol and phellonic acid is

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

  1. Wax

  2. Cutin

  3. Suberin

  4. Sterol

Show answer
Correct Option: C
Explanation:

Suberin is a type of lipid found in the cell wall of plants especially cork cells. It is a mixture of fatty acid material along with glycerol and phellonic acid. It gives rigidity and strength to cell wall in addition to imparting impermeability to cork cells.  Waxes are esters of long chain fatty acids with cetyl or mericyl alcohol. They are found in leaf surfaces of plants, bees wax, wool fat of animal furs and ear wax.  Cutin is a complex lipid formed by polymerisation of  hydroxy fatty acids with or without esterification by alcohols other than glycerol. It is found in the epidermal cell walls of plants and also as a separate layer outer to epidermis. It prevents the water loss due to transpiration. 

Sterols are complex lipids having one or more hydroxyl groups. For example cholesterol in animals provide stability to cell memebrane and also helps in synthesis of vitamin D in response to light. It is also an important component of various hormones such as testosterone, aldosterone, estrogen and progesterone.
Thus, the correct answer is option C. 

Among the following edible fishes which one is a marine fish having rich source of omega-3 fatty acids

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

  1. Mackerel

  2. Mystus

  3. Magur

  4. Mrigala

Show answer
Correct Option: A
Explanation:

The most widely available dietary source of omega-3 fats is oily fish, such as salmon, herring, mackerel, anchovies, menhaden, and sardines. All types of mackerel are higher-fat fish, rich in the healthful polyunsaturated fats known as long-chain omega-3s, which may help boost heart health. So, the correct answer is option A.

During symbiotic biological nitrogen fixation. The recognition of rhizobiahost interaction involves two classes of molecules there are _______________.

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

  1. Lectins an lipids

  2. Lectins and Polysaccharides

  3. Flavonoids and lipids

  4. Lectins and Alkaloids

Show answer
Correct Option: A

The major driving force for the formation of membrane lipid bilayer 

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

  1. vander waal forces

  2. electrostatic force

  3. hydrophobic interactions

  4. H-bond

Show answer
Correct Option: A

Fats, oils, and steroids are

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

  1. Proteins

  2. Nucleic acids

  3. Polysaccharides

  4. Lipids

Show answer
Correct Option: D
Explanation:

Lipids are storage compounds, triglycerides serve as reserve energy of the body. These are an important component of cell membranes structure in eukaryotic cells that helps in regulating membrane permeability. They serve as the source for fat-soluble vitamins like A, D, E, K. Example of lipids are fats, oils and steroids.

So the correct option is 'Lipids'.

In a phospholipid bilayer, the lipid molecules are sandwiched between

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

  1. hydrophobic heads; hydrophilic tails

  2. hydrophobic tails; hydrophilic heads

  3. hydrophilic heads; hydrophilic tails

  4. hydrophobic tails; hydrophobic heads

Show answer
Correct Option: B
Explanation:
In the fluid mosaic model of the cell membrane, proposed by Singer-Nicolson in 1972, the phospholipid bilayer has integrated as well as peripheral proteins embedded in it. In this model, the lipid molecules are sandwiched between hydrophobic tails and hydrophilic heads.
So, the correct answer is 'hydrophobic tails; hydrophilic heads'.

The major site of lipid synthesis in most cells is?

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

  1. Cytoplasmic ribosome's

  2. Outer membrane of mitochondria

  3. Endoplasmic reticulum

  4. Golgi membranes

Show answer
Correct Option: A

Choose the correct answer from the alternatives given.
Which of the following function does the lipid bilayer component of the cell membrane not provide for the cell?

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

  1. Controls the exchange of matter and chemical information between one cell and adjacent cells or the environment

  2. Provides an impermeable, self-sealing membrane capable of dividing or fusing the cell without breaking

  3. Provides the matrix into which proteins are inserted that facilitate the exchange of matter between the inside and outside of the cell

  4. Clearly defines a boundary preventing an equilibrium between the outside and inside of the cell

Show answer
Correct Option: B
Explanation:
The lipid bilayer of the cell membrane does not completely isolate the cell from its surrounding instead, it is a semipermeable membrane with pores and receptors that allows a selective exchange of material and information between the environment inside and the outside the cell.
So, the correct answer is 'Provides an impermeable, self-sealing membrane capable of dividing or fusing the cell without breaking'.

The Lipid derivatives which occur in faecal material are

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

  1. Cholesterol

  2. Ergesterol

  3. Lanoline

  4. Coprosterol

Show answer
Correct Option: D
Explanation:

Many animals, plants and yeast synthesize sterols and their derivatives. Sterols are widely distributed in living organisms as lipid constituents. Cholesterol is a major sterol found as component of plasma membrane lipid bilayer in higher animals such as humans and other mammals. Cholesterol is metabolised to bile acids and steroid hormones. Intestinal microorganisms reduce a certain amount of cholesterol to coprosterol which is then excreted out as faeces. A form of coprosterol termed as 5-coprosterol has a low water solubility and therefore remains stable for many hundreds of years in the environment. Coprosterol is therefore, also used as an indicator of faecal pollution in water from different sources. Ergosterol is a sterol found in fungi and protozoa necessary for their survival and has functions similar to that of cholesterol. Lanolin is a lipid derivative secreted by the sebaceous glands of wool bearing animals. Lanolin is a wax, but it is not a true fat since it lacks glycerides.
So, the correct answer is option D.

This is wax.

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

  1. Palmitic acid

  2. Ethyl palmitate

  3. Hexacosyl palmitate

  4. Sodium stearate

Show answer
Correct Option: C
Explanation:

Wax is a long chain of sterol ester. These are hydrophobic. They are insoluble in water but soluble in organic and nonpolar solvents. It consists of long alkyl chains. Hexacosyl palmitate is an ester derived from the palmitic acid and cetyl alcohol. It is white in color and forms an important constituent of tissues of stony corals. It is the main constituent of bee wax.

So, the correct answer is option C.