Enzymes

Question 1

What are enzymes?

Answer 1

they are proteins that speed up rate of reaction by acting as a biological catalyst

Question 2

What do biological catalyst do?

Answer 2

they catalyse metabolic reactions - both at cellular level (e.g. respiration) and for organism as a whole (e.g. digestion)

Question 3

What can enzymes affect?

Answer 3

structures in an organism as well as function

Question 4

What is catalase and the role of it?

Answer 4

Its an enzyme that works inside cells to catalyse the breakdown of hydrogen peroxide to harmless h2o +o2. H2O2 is the toxic by-product several cellular reactions. if left to build up, it can kill cells.

Question 5

where do amylase and trypsin work?

Answer 5

they work outside cells in the human digestive system.

Question 6

where is amylase found and the role of it?

Answer 6

> Amylase is found in saliva. its secreted into the mouth by cells in the salivary glands.
It catalyses the hydrolysis of starch into maltose in the mouth.

Question 7

whats the role of Trypsin? and how is it produces?

Answer 7

> it catalyses the hydrolysis of peptide bonds - turning big polypeptides into smaller ones (which then get broken down into amino acids by other enzymes).
its produced by cells in the pancreas and secreted into smaller intestines

Question 8

what shape are enzymes?

Answer 8

globular shape

Question 9

what is the active site?

Answer 9

its the part of the enzyme where the substrate molecules bind to

Question 10

what shape does and active site have and what is it determined by?

Answer 10

active site has a specific shape, which is determined by the enzymes tertiary structure

Question 11

For the enzyme to work…

Answer 11

…the substrate shape has to be complementary.

Question 12

what is an enzyme-substrate complex?

Answer 12

its when an enzyme substrate binds to an enzymes active site.

Question 13

what is activation energy?

Answer 13

its the amount of energy of energy which needs to be supplied to the chemicals before the reaction start

Question 14

what reduce the amount of activation energy thats needed?

Answer 14

enzymes reduce the amount of activation energy thats needed, making reactions happen at lower temperatures than they could without an enzyme which speeds up the rate of reaction.

Question 15

What lowers the activation energy?

Answer 15

when an enzyme substrate complex is formed it lowers the activation energy

Question 16

how does an enzyme substrate complex been formed lovers the activation energy?

Answer 16

> because if molecules are joined, it reduces any repulsion between the molecules so they can bond more easily
if its a breakdown reaction, fitting into the active site puts a strain on bonds in the substrate which means the molecule break up easily

Question 17

explain lock and key model

Answer 17

its where the substrate fits into the enzyme in the same way as a key fits into a lock - the active site has a complementary shape.

Question 18

Explain induced fit model

Answer 18

its where the substrate binds to active site and cause change in the shape of active site to be even more complementary to the substrate. This outs a strain on the bonds & make it more likely to read.