Tag: bio-chemistry

Questions Related to bio-chemistry

What is the difference between full cream milk, standard milk, toned, double toned milk?

bio-chemistry biochemical techniques centrifugation separation techniques separation of matter

  1. Amount of fat

  2. Difference in colour

  3. Difference in type of centifugation method used

  4. None of the above

Show answer
Correct Option: A
Explanation:

Milk with different fat contains is available in the market. Full cream milk contains 6% of fat. Standard milk contains 3% fat double and toned milk contains 1% fat.

Nowadays we get full cream, toned and double-toned varieties of milk placed in polypacks or tetra packs in the market. What is the basic concept behind this?

bio-chemistry biochemical techniques centrifugation separation techniques separation of matter

  1. Distillation

  2. Centrifugation

  3. Decantation

  4. Sedimentation

Show answer
Correct Option: B
Explanation:

Centrifugation method is also used for separating cream from milk. When milk is rotated at high speed, the cream collects at the centre and is removed through an outlet.

Centrifugation is used for :
(a) particles which can't be seperated by filteration.
(b) particles which pass through a filter paper.
(c) seperating cream from milk.

bio-chemistry biochemical techniques centrifugation separation techniques separation of matter

  1. a, b, c

  2. a, b

  3. a, c

  4. b, c

Show answer
Correct Option: A
Explanation:

Centrifugation is a technique of separation cream from milk. This is used for particles which are very small and can easily pass through filter paper for particles which can't be seperated by filtration.

In centrifugation :

bio-chemistry biochemical techniques centrifugation separation techniques separation of matter

  1. denser particles settle down

  2. lights particles stay at it top

  3. there are no distinction between lights or denser particles

  4. Both A and B

Show answer
Correct Option: D
Explanation:

In centrifugation, denser particles settle down at the bottom of it container and the lighter particles stay at the top. Suspended particles are rotated at a high speed.

In centrifugation, the mixture containing suspended particles are rotated :

bio-chemistry biochemical techniques centrifugation separation techniques separation of matter

  1. at very slow speed

  2. at high speed

  3. at moderate speed

  4. it varies

Show answer
Correct Option: B
Explanation:

The mixture containing suspended particles are rotated at high sped. Thus the denser particles settle down and lighter particle stay at the top.

Principle of centrifugation is :

bio-chemistry biochemical techniques centrifugation separation techniques separation of matter

  1. denser particles stay at the top and the lighter particles are forced to the bottom

  2. lighter particle stay at the top and the denser particles are forced to the bottom

  3. high speed rotation increases the velocity of particles and make them charged

  4. particles become weightless due to high speed rotation

Show answer
Correct Option: B
Explanation:

The principle behind centrifugation is that the denser particles are forced to the bottom and the lighter particles stay at it top when spin rapidly.

A ___________ is a centrifugal device that separates milk into cream and skimmed milk.

bio-chemistry biochemical techniques centrifugation separation techniques separation of matter

  1. condenser

  2. sublime

  3. separator

  4. all of the above

Show answer
Correct Option: C
Explanation:

A separator is a centrifugal device that separates milk into cream and skimmed milk. When spun, the heavier milk is pulled outward against the walls of the separator and the cream, which is lighter, collects in the middle.

Blood cells are separated from plasma (the liquid part of blood) by :

bio-chemistry biochemical techniques centrifugation separation techniques separation of matter

  1. distillation

  2. centrifugation

  3. sedimentation

  4. chromatography

Show answer
Correct Option: B
Explanation:

A centrifuge is a spinning machine, a bit like a clothes dryer, that separates materials. A mixture of liquids and solids is spun at high speed in a tube. The larger, denser particles sink and collect at the bottom. Light particles collect at the top. Blood cells are separated from plasma (the liquid part of blood) by this method.

Butter from curd can be removed by :

bio-chemistry biochemical techniques centrifugation separation techniques separation of matter

  1. sedimentation

  2. centrifugation

  3. filteration

  4. all of above

Show answer
Correct Option: B
Explanation:

In the method of centrifugation, the centripetal and centrifugal forces are used to separate lighter and heavier components of mixture of two immiscible liquids. When curd is centrifuged, water which is lighter than fat, migrates away from the centre of centrifuge while fat is forced towards the bottom, which is drained out.

Which of the following is a better method than filtration for separation of very small solids?

bio-chemistry biochemical techniques centrifugation separation techniques separation of matter

  1. Distillation

  2. Chromatography

  3. Separating funnel

  4. Centrifugation

Show answer
Correct Option: D
Explanation:

Sometimes the solid particles in a liquid are very small and can pass through a filter paper. For such particles, the filtration technique cannot be used for separation. Such mixtures are separated by centrifugation.