Tag: catalysis

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Questions Related to catalysis

Multiple choice chemistry surface chemistry enzyme catalysis catalysis proteins and enzymes

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

  1. transport oxygen

  2. provide immunity

  3. catalyse biochemical reaction

  4. none of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
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.

Multiple choice chemistry surface chemistry enzyme catalysis catalysis proteins and enzymes

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:

  1. slow

  2. medium

  3. fast

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

Multiple choice chemistry surface chemistry enzyme catalysis catalysis proteins and enzymes

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

  1. maltase

  2. zymase

  3. diastase

  4. lipase
Reveal answer Fill a bubble to check yourself
C Correct answer
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 } } $
Multiple choice chemistry surface chemistry enzyme catalysis catalysis proteins and enzymes

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

  1. streptokinase

  2. amylases

  3. invertase

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

Multiple choice chemistry surface chemistry enzyme catalysis catalysis proteins and enzymes

An enzyme present in the saliva of human beings is :

  1. thiamine

  2. riboflavin

  3. amylases

  4. none of these
Reveal answer Fill a bubble to check yourself
C Correct answer
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.

Multiple choice chemistry surface chemistry enzyme catalysis catalysis proteins and enzymes

Active sites are essential for enzyme action.

  1. True

  2. False
Reveal answer Fill a bubble to check yourself
A Correct answer
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.
Multiple choice chemistry surface chemistry enzyme catalysis catalysis proteins and enzymes

$Cl^-$ ions act as activators for:

  1. amylases

  2. peptidases

  3. glycosidases

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

Multiple choice chemistry surface chemistry enzyme catalysis catalysis proteins and enzymes

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

  1. critical temperature

  2. room temperature

  3. absolute temperature

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