Tag: catalysis

Questions Related to catalysis

The function of enzymes in the non-living system is to:

chemistry surface chemistry enzyme catalysis catalysis proteins and enzymes

  1. transport oxygen

  2. provide immunity

  3. catalyse biochemical reaction

  4. none of the above

Show answer
Correct Option: C
Explanation:

A fundamental task of proteins is to act as enzymes catalysts that increase the rate of virtually all the chemical reactions within cells. Although RNAs are capable of catalyzing some reactions, most biological reactions are catalyzed by proteins. In the absence of enzymatic catalysis, most biochemical reactions are so slow that they would not occur under the mild conditions of temperature and pressure that are compatible with life. Enzymes accelerate the rates of such reactions by well over a million-fold, so reactions that would take years in the absence of catalysis can occur in fractions of seconds if catalyzed by the appropriate enzyme.

In a fermentation tank, molasses solution is mixed with yeast enzymes. After three days alcohol was observed. The speed of the reaction in this case is:

chemistry surface chemistry enzyme catalysis catalysis proteins and enzymes

  1. slow

  2. medium

  3. fast

  4. very fast

Show answer
Correct Option: A
Explanation:

The maximum concentration of alcohol possible through a natural fermentation is about $12\%$ ethanol,

after this the alcohol concentration fatal for yeast and it can't survive, that's why after some time the speed of the reaction is slow.

Starch converts into maltose by the catalytic action of the enzyme:

chemistry surface chemistry enzyme catalysis catalysis proteins and enzymes

  1. maltase

  2. zymase

  3. diastase

  4. lipase

Show answer
Correct Option: C
Explanation:
Starch converts into maltose by teh action of Diastase enzyme.

$\underset { starch }{ 2{ \left( { C } _{ 6 }{ H } _{ 10 }{ O } _{ 5 } \right)  } _{ n } } +n{ H } _{ 2 }O\xrightarrow [  ]{ Diastase } \underset { maltose }{ n{ C } _{ 12 }{ H } _{ 22 }{ O } _{ 11 } } $

Name of an enzyme used to dissolve the blood clot is :

chemistry surface chemistry enzyme catalysis catalysis proteins and enzymes

  1. streptokinase

  2. amylases

  3. invertase

  4. phenylketoneurea

Show answer
Correct Option: A
Explanation:

Streptokinase is used to dissolve blood clots that have formed in the blood vessels. It is used immediately after symptoms of a heart attack occur to improve patient survival. This medicine may also be used to treat blood clots in the lungs (pulmonary embolism) and in the legs (deep venous thrombosis).

An enzyme present in the saliva of human beings is :

chemistry surface chemistry enzyme catalysis catalysis proteins and enzymes

  1. thiamine

  2. riboflavin

  3. amylases

  4. none of these

Show answer
Correct Option: C
Explanation:

Ptyalin is the starch hydrolyzing enzyme secreted by salivary glands in human beings. It is also called as salivary amylase. Ptyalin secreted in the mouth brings about digestion of starch in the mouth itself.

Active sites are essential for enzyme action.

chemistry surface chemistry enzyme catalysis catalysis proteins and enzymes

  1. True

  2. False

Show answer
Correct Option: A
Explanation:
The active site is the region of an enzyme where substrate molecules bind and undergo a chemical reaction. The active site consists of residues that form temporary bonds with the substrate (binding site) and residues that catalyse a reaction of that substrate (catalytic site).
Thus, the active site of the enzyme is responsible for its catalytic action. Thus it is essential for enzyme action.

Holoenzymes are complete and active enzymes.

chemistry surface chemistry enzyme catalysis catalysis proteins and enzymes

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

True, Holoenzymes are complete and active enzymes.

Holoenzymes are made up of Apoenzyme(Protein part) and Cofactor(Non-protein part) that makes a complete protein structure.

Metal ions can activate enzymes.

chemistry surface chemistry enzyme catalysis catalysis proteins and enzymes

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

Yes, Metals ion can active enzymes.

These can change its shape by activating enzyme but are not actually involved in catalytic action.

$Cl^-$ ions act as activators for:

chemistry surface chemistry enzyme catalysis catalysis proteins and enzymes

  1. amylases

  2. peptidases

  3. glycosidases

  4. lipases

Show answer
Correct Option: A
Explanation:

$Cl^{-}$ ions act as activators for amylase enzyme.

Enzyme activators:-Enzyme activators are molecules that bind to enzymes and increase their activity. They are the opposite of enzyme inhibitors. These molecules are often involved in the allosteric regulation of enzymes in the control of metabolism.

The temperature at which the catalytic activity of the catalyst is maximum, is called: 

chemistry surface chemistry enzyme catalysis catalysis proteins and enzymes

  1. critical temperature

  2. room temperature

  3. absolute temperature

  4. optimum temperature

Show answer
Correct Option: D
Explanation:

Some catalysts are, however, physically altered by a rise in temperature and hence their catalytic activity may be decreased. This is particularly true with colloidal solutions like that of platinum, since a rise in the temperature may cause their coagulation. In such a case, the rate of reaction increases up to a certain point and then gradually decreases. The rate of reaction is maximum at a particular temperature; that is Optimum temperature.