Enzymes

Question 1

what are enzymes?

Answer 1

protein biocatalysts that speed up the rate of metabolism.

Question 2

what is metabolism? which enzyme is responsible to break down starch?

Answer 2

the chemical reactions in the body’s cells that change food into energy.
amylase.

Question 3

catabolism & anabolism are type of _________.
define catabolsim and anabolism with examples.

Answer 3

metabolism
reactions which break down complex molecules into simpler molecules. c
reactions which build complex molecules from simpler molecules. a

catabolism= cat = cat eats so breaks down

Question 4

energy is _________ in anabolism & _____ in catabolism.
what are substrates?
what are products?
what are metabolic pathways?

Answer 4

utilized
released
a molecule that an enzyme reacts upon.
changed substrates.
In a metabolic pathway, one enzyme takes the product of another enzyme as a substrate. After the reaction, the product is passed on to the next enzyme.

Several enzymes can work together in a specific order, creating metabolic pathways

Question 5

what are intracellular & extracellular enzymes? with examples. on what basis it’s categorized?

Answer 5

intracellular enzymes are found inside cells to speed up the reactions.
Extracellular enzymes are located outside of cells and are used to interact with other molecules outside the cell.
on the basis of the site where they work.

bacteria & fungi releases extracellular enzymes to digest their food.

eg. glycolysis enzymes in cytoplasm
eg. pepsin enzyme in stomach cavity

Question 6

are all enzymes protein?
why are enzymes so specific?
some imp. vitamins act as ___________.

Answer 6

yes except ribozyme which is made of RNA & not amino acids.
because the active site should fit perfectly in the substrate.
conenzymes (cofactor)

Question 7

what are cofactors?

Answer 7

many enzymes require non-protein helpers for their proper working
3 types
activators
prosthetic group
coenzymes

Question 8

If organic cofactors are tightly bound to enzyme, they are called
___________________.
If organic cofactors are loosely attached with enzyme, they are called _____________.
define active site?

Answer 8

prosthetic groups
coenzymes
the site on an enzyme where the substrate binds with enzyme.

Question 9

define all?examples of all cofactors

Answer 9

zinc, iron, copper, chloride ions
haem group
NAD, coenzyme A, vitamin A

its called group cz cofactor is permanent.

Question 10

enzyme activity can be regulated by _______________. define

Answer 10

inhibitors & activators
Enzyme inhibitors bind to enzymes and prevent them from catalyzing reactions.
Enzyme activators enhance their catalytic activity.

Question 11

name all charcateristics of enzymes.

Answer 11

7

Question 12

define energy of activation? if it’s not possible for energy to be there at body temp. then how does it happen?

Answer 12

minimum energy required to start a reaction.
enzymes lower the activation energy so it can take place at body temp.

Question 13

how do enzymes lower activation energy?

Answer 13

4

Question 14

define optimum temperature? optimum temperature for human enzymes?

Answer 14

Every enzyme works at its maximum rate at a specific temperature called as the optimum temperature for that enzyme.
36 C to 38 C

Question 15

how does increase in temperature increases enzyme activity?

Answer 15

by enhancing molecular collisions and providing greater kinetic energy, lowering activation energy for reactions. However, beyond the optimal temperature, excessive heat can cause enzyme denaturation, leading to a loss of activity as the protein structure is irreversibly damaged.

Question 16

if the temperature in increased above optimum, then _________________________.
if the temp. is decreased to _________, then _____________________.

Answer 16

enzymes are denatured.
below freezing point
enzymes are inactivated but not denatured. They’ll regain their catalytic activity when higer temperature are restored.

Question 17

define optimum pH? example? what happens if pH is much higher or lower?

Answer 17

All enzymes work at their maximum rate at a narrow range of pH.
pepsin (working in stomach) is active
in acidic medium (low pH) while trypsin (working in small intestine) shows its activity in alkaline medium (high pH).
enzyme is denatured.

Question 18

the rate of an enzyme catalysed reaction is _________ proportional to the substrate concentration.

Answer 18

directly
if we double the substrate concentration, then rate of reaction would also double.
because more substrate molecule are colliding with active site so rate of reaction would be fast.

Question 19

If enzyme concentration is kept
constant and amount of substrate is increased, then _____________.

Answer 19

a point is reached where any further increase in substrate does not increase the rate of reaction any more.
This is becuase at any given moment, the active site of all the enzymes molecules are saturated by substrate molecules. This state is called saturation of **active sites **and reaction rate does not increase.

Question 20

who proposed the enzyme models? what is enzyme substrate/ product complex? draw the diagram of the models. describe the models.

Answer 20

Emil Fischer
Daniel Koshland
the enzyme combines with substrate.

Question 21

example of specifity of enzymes? what is one thing that specifies the substrate on enzyme?

Answer 21

protease- proteins
lipase- lipids
amylase- starch
shape of active site.