Tag: lipids

Quizzes (3) Questions (164)

Questions Related to lipids

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

A product of glycerol and phellonic acid is

  1. Wax

  2. Cutin

  3. Suberin

  4. Sterol
Reveal answer Fill a bubble to check yourself
C Correct answer
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. 

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

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

  1. Mackerel

  2. Mystus

  3. Magur

  4. Mrigala
Reveal answer Fill a bubble to check yourself
A Correct answer
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.

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

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

  1. Lectins an lipids

  2. Lectins and Polysaccharides

  3. Flavonoids and lipids

  4. Lectins and Alkaloids
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In the symbiotic relationship between legumes and rhizobia, the initial recognition involves lectins (on the plant side) and specific polysaccharides or lipids on the bacterial surface.

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

The major driving force for the formation of membrane lipid bilayer 

  1. vander waal forces

  2. electrostatic force

  3. hydrophobic interactions

  4. H-bond
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The major driving force for the spontaneous formation of the lipid bilayer in biological membranes is the hydrophobic effect. Water molecules form an ordered cage around hydrophobic tails, and aggregation of these tails increases water entropy, stabilizing the bilayer.

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

Fats, oils, and steroids are

  1. Proteins

  2. Nucleic acids

  3. Polysaccharides

  4. Lipids
Reveal answer Fill a bubble to check yourself
D Correct answer
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'.

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

In a phospholipid bilayer, the lipid molecules are sandwiched between

  1. hydrophobic heads; hydrophilic tails

  2. hydrophobic tails; hydrophilic heads

  3. hydrophilic heads; hydrophilic tails

  4. hydrophobic tails; hydrophobic heads
Reveal answer Fill a bubble to check yourself
B Correct answer
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'.
Multiple choice biology food and it's constituents functions and principal sources of lipids chemical organization in living beings lipids

The major site of lipid synthesis in most cells is?

  1. Cytoplasmic ribosome's

  2. Outer membrane of mitochondria

  3. Endoplasmic reticulum

  4. Golgi membranes
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The endoplasmic reticulum (specifically the smooth endoplasmic reticulum) is the primary site for the synthesis of most membrane lipids, phospholipids, and cholesterol in eukaryotic cells.

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

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?

  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
Reveal answer Fill a bubble to check yourself
B Correct answer
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'.
Multiple choice biology food and it's constituents functions and principal sources of lipids chemical organization in living beings lipids

The Lipid derivatives which occur in faecal material are

  1. Cholesterol

  2. Ergesterol

  3. Lanoline

  4. Coprosterol
Reveal answer Fill a bubble to check yourself
D Correct answer
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.

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

This is wax.

  1. Palmitic acid

  2. Ethyl palmitate

  3. Hexacosyl palmitate

  4. Sodium stearate
Reveal answer Fill a bubble to check yourself
C Correct answer
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.