Tag: bio-chemistry

Quizzes (82) Questions (1918)

Questions Related to bio-chemistry

Multiple choice bio-chemistry lipids functions of lipids biomolecules: chemical constituents of living cells biochemistry

Source of turpentine oil is

  1. Bark of Cinchona

  2. Lichen

  3. Gymnospermous wood

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

Turpentine oil is an oil which is a volatile oil which is mainly obtained from pines a gymnospermic plant. It is obtained by distillation of resin. Terpenes are the derivative of terpene oil. It is used for thinning oil based paints. It is a very good source of organic synthesis. It is highly viscous in nature. The solid material left behind after distillation is known as rosin.

So, the correct answer is option C.

Multiple choice bio-chemistry lipids functions of lipids biomolecules: chemical constituents of living cells biochemistry

Prostaglandins are made from

  1. Steroid

  2. Carbohydrate

  3. Amino acid

  4. Fatty acid
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Arachidonic acid is a polyunsaturated omega-6 fatty acid. It is present in the phospholipids and helps in the formation of membranes. It is the most abundant fatty acid in the brain. It is a precursor for the synthesis of prostaglandins. The prostaglandins synthesized is PG$ _2$. They are autocrine and paracrine lipid mediators that act upon platelets, endothelium, uterine and mast cells. 
So, the correct answer is option D.
Multiple choice bio-chemistry lipids functions of lipids biomolecules: chemical constituents of living cells biochemistry

Prostaglandins synthesized from

  1. Amino acids

  2. Fatty acids

  3. Carbohydrates

  4. Steroids
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
Prostaglandins are synthesized by arachidonic acid. Arachidonic acid is a polyunsaturated omega-6 fatty acid. It is present in the phospholipids and helps in the formation of membranes. 
The prostaglandins synthesized is PG$ _2$. They are autocrine and paracrine lipid mediators that act upon platelets, endothelium, uterine and mast cells. It belongs to a class of fatty acid derivative.
So, the correct answer is option B.
Multiple choice bio-chemistry lipids functions of lipids biomolecules: chemical constituents of living cells biochemistry

What is true of membrane lipids and proteins?

  1. None can flip-flop

  2. Both can flip-flop

  3. Proteins can flip-flop but lipids cannot.

  4. Lipids flip-flop but proteins rarely flip-flop
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Lipid bilayer of the cell membrane contains hydrophilic head groups facing outward and hydrophobic tails facing each other. The transport of phospholipids and lipid-linked oligosaccharides is difficult to achieve due to this bipolar nature. The transmembrane lipid transporter proteins called flippases transport lipids across cell membrane through transverse diffusion by flipping their orientation. Floppases transport in reverse direction. In mammals, this affects various processes such as blood coagulation, immune recognition, and programmed cell death.Most protein molecules do not flipflop due to their extensive polar regions, which are unfavorable in the hydrophobic core of the membrane.

Option D is correct.

Multiple choice bio-chemistry lipids functions of lipids biomolecules: chemical constituents of living cells biochemistry

The exine of mature pollen grain is composed chiefly ____________.

  1. Lipids

  2. Cellulose

  3. Pectocellulose

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

The exine layer of a pollen grain is exceptionally hard and resistant to high temperatures, strong acids, and alkalis because it is chiefly composed of sporopollenin, a remarkably durable organic polymer. Cellulose and pectocellulose make up the intine layer, while lipids are found in various pollen coatings.

Multiple choice bio-chemistry lipids functions of lipids biomolecules: chemical constituents of living cells biochemistry

Why tails of lipids in the membrane are towards inner part?

  1. The tails is non-polar hydrocarbon and so, protected with an aqueous environment

  2. The tail is polar hydrocarbon and so, is protected from aqueous environment

  3. The non-polar or hydrophobic hydrocarbon trails of lipid, being on inner side ensure their protection from aqueous environment.

  4. The tail is hydrophilic so, it tends to be located in the aqueous inner side of membrane
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The tails of the lipids are made up of fatty acids. These are non-polar hydrophobic so they tend to arrange away from the cytoplasmic face as well as the extracellular face. So, they avoid aqueous medium by arranging themselves towards the inner part of the cell membrane.

Hence, the correct answer is 'The non-polar or hydrophobic hydrocarbons tails of lipid, being on inner side ensure their protection from the aqueous environment.

Multiple choice bio-chemistry lipids functions of lipids biomolecules: chemical constituents of living cells biochemistry

Which of the following can be traced in phospholipids of brain tissue and soybeans?

  1. Phosphoglycerides

  2. Phosphoinositides

  3. Cholesterol

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

Phosphoinositides make up a small fraction of cellular phospholipids, They play a fundamental role in controlling membrane-cytosol interfaces, regulation of membrane traffic and the permeability and transport functions of membranes. They are found in brain tissue in animals and soybean seeds. Thus the correct answer is option B.

Multiple choice bio-chemistry lipids functions of lipids biomolecules: chemical constituents of living cells biochemistry

Deficiency of EFA causes

  1. Follicular keratosis

  2. Kidney failure

  3. Sterility

  4. All the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Essential fatty acids (EFA) are those fatty acids that body cannot produce on its own and therefore must be supplied from the diet. Deficiency of EFA causes many disease conditions like dry and scaly skin, follicular keratosis (hard and dry skin around hair follicles), bumps on back of upper arms, color variation of skin, dry eyes, mouth and throat, menstrual cramps, dry vagina, excessive thirst, eczema, asthma, hay fever, painful joint. In severe cases, it may result in kidney failure and sterility.

Thus, the correct answer is option D. 

Multiple choice bio-chemistry coordination in life processes role of intestine digestion in intestine mechanism of digestion

Ammonia formed during digestion is processed in

  1. Liver

  2. Small intestine

  3. Large intestine

  4. Stomach
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation
  • During digestion, the deamination of amino acids results in the production of ammonia (NH3). 
  • However, the liver contains a system of carrier molecules and enzymes which quickly converts the ammonia (and carbon dioxide) into urea
  • This ammonia is an extremely toxic base and its accumulation in the body may cause death.  Hence,  Ammonia is formed during digestion in the liver.
So, the correct answer is 'liver'.
Multiple choice bio-chemistry coordination in life processes role of intestine digestion in intestine mechanism of digestion digestive system - organs

Which of the options given below would not correctly fill the blanks in the following sentence?


In order to absorb and use ____ by the body, these must be broken down by hydrolysis into ___.

  1. Polysaccharides, Monosaccharides

  2. Amino acids, Proteins

  3. Fats, Glycerol and Fatty acids

  4. Disaccharldes, Monosaccharides
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • Proteins are converted into dipeptides in the stomach which is followed by the conversion of dipeptides to amino acids in the small intestine. These amino acids are absorbed through the wall of the intestine as simple absorbable substances.
  • Hence In order to absorb and use Proteins by the body, these must be broken down by hydrolysis into proteins.
  • So, the correct answer is 'amino acids, proteins'.