chapter 4

Question 1

what are anabolic reactions

Answer 1

they are required for growth and (building up)

Question 2

what are catabolic reactions

Answer 2

they are required for breaking down

Question 3

what is induced fit hypothesis

Answer 3

When the enzyme and substrate form a
complex, the structure of the enzyme is altered so that the active site of the enzyme fits around the substrate

Question 4

what is activation energy

Answer 4

the energy a reaction needs to start up

Question 5

what are intracellular enzymes

Answer 5

enzymes reacting inside the cell

Question 6

what do extracellular enzymes do

Answer 6

break down large nutrients into small molecules outside the cell so nutrients can be absorbed

Question 7

how is starch broken down

Answer 7

starch polymers is partially broken down into maltose (disaccharide)
the enzyme is called amylase
amylase produced by salivary glands

Question 8

how is maltose broken down after its polymer (starch) has been broken down

Answer 8

broken down into glucose (monosaccharide)
the enzyme doing this is called maltase

Question 9

what happens in the digestion of proteins

Answer 9

gets broken down into amino acids
trypsin is a type of protease

Question 10

how does enzyme concentration effect reactions

Answer 10

the rate of reaction increases as enzyme concentration increases as there are more active sites for substrates to bind to, however increasing the enzyme concentration beyond a certain point has no effect on the rate of reaction as there are more active sites than substrates so substrate concentration becomes the
limiting factor

Question 11

how does substrate concentration effect reactions

Answer 11

as concentration of substrate increases, rate of reaction increases as more enzyme-substrate complexes are formed. However, beyond a certain point the rate of reaction no longer increases as enzyme concentration becomes the limiting factor

Question 12

how does temperature effect reactions

Answer 12

rate of reaction increases up to the optimum temperature, which is the temperature at which enzymes work at their maximum rate.

Question 13

what’s an inhibitor

Answer 13

a substance which slows down or stops a reaction by affecting the binding of substrate to the enzymes. Inhibitors can either be reversible and irreversible

Question 14

what’s an example of a irreversible inhibitor

Answer 14

Examples of irreversible inhibitors include heavy metal ions such as mercury and silver
which cause disulphide bonds within the protein structure to break, as a result causing the shape of the active site to change, thus affecting protein activity

Question 15

what’s a reversible inhibitor

Answer 15

they bind to the active site through hydrogen bonds and weak ionic
interactions therefore they do not bind permanently. Reversible inhibitors can either be competitive or non-competitive.

Question 16

what’s a competitive inhibitor

Answer 16

similar in structure to the substrate molecule therefore they bind to the active site of the enzyme, decreasing its activity as they compete with substrate for the enzyme. The amount of product formed remains the same, however the rate at which product formation occurs decreases. The higher the concentration of competitive inhibitor the lower the reaction rate. In

Question 17

what’s a non competitive inhibitor

Answer 17

does not bind to the active site; it binds at another site on the enzyme known as the allosteric site. Binding of the non competitive inhibitors changes the shape of the active site therefore preventing the binding of the substrate. Increasing the
concentration of substrate has no effect on non-competitive inhibition.

Question 18

what’s a co factor

Answer 18

a non-protein compound required for the enzyme’s activity to occur. There are three types of cofactors: coenzymes, activators and prosthetic groups

Question 19

what’s a co enzyme

Answer 19

organic cofactors which do not bind permanently. They facilitate the binding of substrate to enzyme. Many coenzymes are vitamin derived

Question 20

what’s a prosthetic group

Answer 20

permanently attached to the enzyme. For instance, haemoglobin contains a prosthetic haem group which contains iron, permanently bound to the molecule, which serves as a means of binding oxygen.

Question 21

what’s an activator

Answer 21

are inorganic metal ions which temporarily binds to the enzyme and alters its active site, making the reaction more feasible. For instance, magnesium ion is an important
activator which is involved in processes such as shielding negative charge

Question 22

role of enzymes

Answer 22

To catalyse reactions that affect metabolism at a cellular and whole organism level. They affect both structure and function.

Question 23

Examples of stuff enzymes help with on the cellular level

Answer 23

Synthesis of cell components, synthesis of polymers from monomers, release of energy

Question 24

Example of thing enzymes help with on the whole organism level

Answer 24

digestion

Question 25

what does catalase do

Answer 25

Ensures that hydrogen peroxide is broken down to form oxygen and water so it doesn’t accumulate as hydrogen peroxide is toxic

Question 26

what type of enzyme in catalase

Answer 26

intracellular

Question 27

How is the formation of an enzyme-substrate complex good for the efficiency of the process?

Answer 27

Temporary bonds formed between R-groups in the active site and the substrate will put strain on the bonds within the substrate, making them easier to break.

Question 28

How do enzymes speed up a reaction

Answer 28

they lower the activation energy because the enzymes help for molecules to collide successfully

Question 29

what’s the effect when increasing the temp over optimum temp to an enzyme

Answer 29

Hydrogen bonds holding the tertiary structure break as the protein vibrates more, breaking bonds changes the tertiary structure and the shape of the enzyme, enzyme has been denatured, shape no longer complementary to the substrate, substrate can’t fit in the active site anymore

Question 30

what is Q10

Answer 30

A measure of how much the rate increases with a 10 degrees celcius rise in temperature

Question 31

Enzyme adaptations of organisms in extremely cold environments

Answer 31

enzymes are flexible which make them less stable

Question 32

enzyme adaptations of organisms in extremely hot environments

Answer 32

more disulfide bonds
more hydrogen bonds

Question 33

How extreme pHs affect enzymes

Answer 33

H+ ions can interact with polar and charged R groups, changing the concentration of H+ ions changes the degree of interaction, a higher concentration of H+ means the R groups will be able to interact with each other less, this breaks bonds and thus changes the shape of the enzyme,

Question 34

whats the cofactor for amylase

Answer 34

Cl−

Question 35

what is the prosthetic group for carbonic anhydrase

Answer 35

Zn2+

Question 36

where can we find coenzymes

Answer 36

vitamins in diet