Tag: bio-chemistry

Questions Related to bio-chemistry

Consider the following statements.
a. Cutin is a fatty acid polymer
b. Starch is composed only of glucose residues
Which of the statements given is/are correct?

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

  1. $1$ only

  2. $2$ only

  3. Both $1$ and $2$

  4. Neither $1$ nor $2$

Show answer
Correct Option: A

Consider the following fatty acids.
a. Linolenic acid
b. Oleic acid
c. Palmitic acid
d. Stearic acid
Which of these is/are unsaturated fatty acids?

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

  1. $1$ only

  2. $1$ and $2$

  3. $3$ and $4$

  4. $2, 3$ and $4$

Show answer
Correct Option: A

Which of the following statements concerning unsaturated fats is correct?

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

  1. They have fewer fatty acid molecules per fat molecule

  2. They have double bonds in the carbon chains of their fatty acids

  3. They generally solidify at room temperature

  4. They contain more hydrogen than do saturated fats having the same number of carbon atoms

Show answer
Correct Option: B
Explanation:

When one or more double bonds are present between the carbon chains of the fatty acids it is known as unsaturated fats. They have a large number of fatty acid molecules per fat molecule. Due to the presence of double bonds they contain a lesser number of hydrogen bonds as compared to the saturated fatty acid molecules.

Hence, the correct answer is 'They have double bonds in the carbon chains of their fatty acids'

Select the correct option:

Which of the following is a saturated fatty acid?

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

  1. Oleic acid

  2. Linoleic acid

  3. Arachidonic acid

  4. Palmitic acid

Show answer
Correct Option: D
Explanation:

Fatty acids are two main types- saturated and unsaturated fatty acids are without double bonds in their carbon chains. They have higher melting points and are solids at room temperature. They have a general formula of $C _nH _{2n}O _2$,e.g., $C _{16}H _{32}O _2$ (palmitic acid), $C _{18}H _{36}O _2$ (stearic acid).

Animal fats are mostly saturated fats.
Unsaturated fatty acids contain one or more double bonds in their carbon chains. They have lower meting points and are liquids at room temperature. Their general formula is $C _nH _{2n-2x} O _2$,e.g., oleic acid (with one double bond, monoene, $C _{18}H _{34}O _2)$, linoleic acid (with two double bonds, diene,$C _{18}H _{32}O _2$),linolenic acid (with three double bonds,triene, $C _{18}H _{30}O _2$).arachidonic acid (with four double bonds,tetraene,$C _{20}H _{32}O _2$).Plant fats are generally unsaturated fats.
So, the  correct answer is 'Palmitic acid'.

Which among the following is not a common saturated fatty acids encountered in nature?

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

  1. Butyric acid

  2. Palmitoleic

  3. Acetic and palmitic

  4. None of the above

Show answer
Correct Option: B
Explanation:

Fatty acids are carboxylic acids with hydrocarbon chains of 4 to 36 carbons. In some fatty acids, this chain is fully saturated (meaning it cannot accept any more hydrogens) and unbranched; other fatty acids contain one or more double bonds (thus, they can be hydrogenated when the double bonds will get converted into single bonds).

Common examples of saturated fatty acids are butyric acid having four carbon atoms, lauric acid having twelve carbon atoms, myristic acid having fourteen carbon atoms, palmitic acid having sixteen carbon atoms, etc. Common unsaturated fatty acids are palmitoleic acid having sixteen carbon atoms and one double bond, oleic acid having eighteen carbon atoms and one double bond, linolenic acid having eighteen carbon atoms and two double bonds, etc.

Which one of the following is not an essential fatty acid?

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

  1. Linoleic acid

  2. Linolenic acid

  3. Arachidonic acid

  4. None of the above

Show answer
Correct Option: C
Explanation:

Arachidonic acid is not an essential fatty acid because it can be synthesized by the cells in the body from linoleic acid. All the other three are essential fatty acids.

So, the correct answer is 'Arachidonic acid'.

How many of fatty acids/ fats given below do you except to have low melting points and remain as liquids in waters?
Palmitic acid, gingelly oil, arachidonic acid, stearic acid, arachidic acid, tripalmitate

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

  1. One

  2. Two

  3. Three

  4. Four

Show answer
Correct Option: D
Explanation:
Palmitic acid, arachidonic acid, stearic acid and arachidic acid are the fatty acids present in the vegetable oil. They are unsaturated fatty acid that have low melting point and remain liquid at room temperature.
So the correct answer is 'four'.

Which one of the following oils is having maximum content of Polyunsaturated Fatty Acids (PUFA)?

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

  1. Coconut oil

  2. Cottonseed oil

  3. Soyabean oil

  4. Sunflower oil

Show answer
Correct Option: D
Explanation:
Polyunsaturated fat is a type of dietary fat. It is one of the healthy fats, along with monounsaturated fat. Polyunsaturated fat is found in plant and animal foods, such as salmon, vegetable oils, and some nuts and seeds. Eating moderate amounts of polyunsaturated (and monounsaturated) fat in place of saturated and trans fats can benefit your health. Polyunsaturated fat is different than saturated fat and trans fat. These unhealthy fats can increase your risk for heart disease and other health problems. Polyunsaturated fats can help lower your LDL (bad) cholesterol. Cholesterol is a soft, waxy substance that can cause clogged or blocked arteries (blood vessels). Having low LDL cholesterol reduces your risk for heart disease.Polyunsaturated fats include omega-3 and omega-6 fats. These are essential fatty acids that the body needs for brain function and cell growth. Sunflower oil has higher amounts of healthy fats than others. 
So the correct option is 'sunflower oil'.

Choose the best definition for 'diffusion' from the following.

bio-chemistry absorption by roots - the processes involved diffusion transport across membrane means of transport

  1. Passive movement from an area of greater concentration to one of lesser concentration

  2. Active movement from an area of greater concentration to one of lesser concentration

  3. Passive movement from an area of lesser concentration to one of greater concentration

  4. Active movement from an area of lesser concentration to one of greater concentration

Show answer
Correct Option: A
Explanation:

Diffusion is a type of passive transport which do not require expenditure of cellular energy for the net movement of a substance from a region of high solute concentration to a region of low solute concentration. This is also referred to as the movement of a substance down a concentration gradient.

Different substances move independently depending on their own concentration gradients in?

bio-chemistry absorption by roots - the processes involved diffusion transport across membrane means of transport

  1. Simple diffusion

  2. Bulk flow

  3. Osmosis

  4. All the above

Show answer
Correct Option: A
Explanation:

Diffusion is a passive movement of molecules along their concentration gradient. While osmosis is the diffusion of water molecules through a differentially permeable membrane or semipermeable membrane.


So the correct option is "Simple diffusion".