enzymes

Question 1

what are biological catalyst?

Answer 1

molecules which speed the rate of reactions

Question 2

are all enzymes biological catalyst?

Answer 2

yes all enzymes are biological catalyst but not all catalyst are enzymes

Question 3

what type of proteins are enzymes?

Answer 3

globular protein

Question 4

describe the 2 type of enzymes which can be found

Answer 4

1- intercellular enzymes
: enzymes which catalyze a reaction within cells2- extracellular enzymes
: enzymes which catalyze reactions outside of the cell

Question 5

how exactly does an enzyme work?

Answer 5

an enzyme works by lowering the activation energy which is the minimum amount of energy needed for successful collision to occur

Question 6

what are the 2 mechanisms of enzymes?

Answer 6

1- lock and key mechanism

2- induced fit mechanism

Question 7

define lock and key mechanism

Answer 7

the lock and key mechanism is where the active site of an enzyme has a very specific shape and can only bind to 1 substrate

Question 8

define induced fit mechanism

Answer 8

the induced fit mechanism is where the active site of an enzyme is able to change slightly to fit onto a substrate

Question 9

what is an enzyme-substrate complex?

Answer 9

an enzyme substrate is the structure which forms when the substrate has binded to the active site of an enzyme

Question 10

what are factors effecting rate of reaction

Answer 10

PH concentration
temperature
enzyme concentration
substrate concentration
inhibitor concentration

Question 11

describe how enzyme concentration effects rate of reaction?

Answer 11

as the enzyme concentration increases, the rate of reaction increases only if there is more than enough substrate

Question 12

describe how substrate concentration effects rate of reaction

Answer 12

initially, as the substrate concentration increases, the rate of reaction increases until the point of saturation where it remains constant

Question 13

what does saturated enzyme mean?

Answer 13

enzyme whose active site are occupied by substrate molecules

Question 14

what is Vmax?

Answer 14

Vmax is when enzymes reach their maximum rate as all enzymes become saturated

Question 15

what is Km?

Answer 15

Michaels men-tent constant which is corresponding X value of 1/2Vmaxx

Question 16

what affinity?

Answer 16

enzymes binding with substrate/ enzymes recognition of a specific substrate

Question 17

what is the relationship between Km, Vmax and affinity?

Answer 17

the greater the Km, the greater the 1/2Vmax where a fast reaction occurs with only higher substrate concentration= having lower affinity

Question 18

what is a buffer solution including how it works?

Answer 18

a buffer solution is used to maintain PH levels by secreting ions

Question 19

describe how PH and temperature affects rate of reaction

Answer 19

as PH and temperature increases, rate of reaction increases to its optimum and then decreases due to denaturation of enzymes

Question 20

what is a competitive inhibitor?

Answer 20

inhibitor which binds to the active site preventing the binding of substrate to active site

Question 21

what is non-competitive inhibitor?

Answer 21

inhibitor which binds to an allosteric site changing the active site of the enzyme

Question 22

describe the benefit of non-competitive inhibitor in ending product production

Answer 22

once enough products are made, the inhibitor binds to the allosteric site changing the shape of the active site preventing products from being formed

Question 23

describe the benefit of non-competitive inhibitor in formation of product

Answer 23

once products made are used, the inhibitor un-binds from the allosteric site restoring active site shape allowing more products to be made

Question 24

what is the relationship of substrate and competitive inhibitors?

Answer 24

the more substrate there is, the more likely it will bind to active site instead of competitive inhibitors

Question 25

what is the relationship of substrate and non-competitive inhibitors?

Answer 25

the amount of substrate does not matter as active site has already been changed

Question 26

what are the characteristics of competitive inhibitor against no inhibitor?
*including explanation

Answer 26

1- same Vmax
: As the substrate increases, less inhibitor binds to the active site allowing reaction to occur normally

2- high Km
: Initially there were more inhibitors than substrate slowing the reaction down causing a higher Km= lower enzyme affinity

Question 27

what are the characteristics of non- competitive inhibitor against no inhibitor?
*including explanation

Answer 27

1-lower Vmax
: the inhibitors disabled the enzyme preventing its maximum rate to be reached

2- same Km
: Despite the disabled enzymes, the working ones were able to work just as well as the no inhibitor reaction causing same km= same affinity

Question 28

what are immobilized enzymes?

Answer 28

enzymes trapped within an inert material unable to move

Question 29

what are methods to immobilize enzymes?

Answer 29

1- entrapment

2-ionice/covalent bonding

Question 30

what are 5 advantages of immobilizing enzymes

Answer 30

1- no contamination of products and enzyme
*products are extracted and enzymes don’t move
2- enzymes can be recovered and re-used
*enzymes found easily and used
3- good for continuous operations
4- greater enzyme stability in varying PH and temp
*protected by the unreactive material
5-many enzymes can react at once in a cell

Question 31

what is a colorimeter?

Answer 31

measures rate of activity involving colors by seeing the color intensity of a solution

Question 32

describe how a colorimeter works

Answer 32

• a specific color/wavelength from a light source is directed towards the sample
• the sample absorbs the specific color
• an output is given showing how much light was absorbed
• a link between light absorbed and color intensity can be made depending on the experiment