Enzymes

Question 1

What is an anabolic reaction

Answer 1

Chemical reactions required for growth

Building up

Question 2

What is a catabolic reaction

Answer 2

Breaking down

Question 3

Enzymes can only increase the rate of reaction up to a certain point, what is this called?

Answer 3

Vmax

Question 4

What energy is needed to be supplied for start of most reactions

Answer 4

Activation energy

Question 5

How do enzymes help molecules

Answer 5

Help them collide more successfully so reduce activation energy needed

Question 6

Deacribe the lock and key hypothesis

Answer 6

Area within tertiary structure of enzyme that has a a shape that is complimentary to a specific substrate molecule
‘Lock and key’
When substrate is bound to active site an enzyme substrate complex is formed. Substrate reacts and forms a enzyme-product complex.
Product is then released,leaving enzyme unchanged

Substrate held in a way atom groups interact
R group on active site interact with substrate too

Question 7

Describe the induced fit model

Answer 7

Active site of an enzyme changes shape as substrate enters. Initial reaction between enzyme and substrate is weak, so change enzyme tertiary structure that strengthen binding on substrate molecule
Weakens a particular Bon in substrate so lower activation energy needed

Question 8

What do all reaction in cells need

Answer 8

Substrates

Question 9

Raw materials need to be supplied to cells, what can supply these materials

Answer 9

In our diet
Proteins
Polysaccharides
Enzymes break down large nutrient molecules into smaller ones

Question 10

What are extra ellipse enzymes

Answer 10

Break down large nutrient molecules into smaller ones by digestion

They work outside of the cell that made them

Question 11

What relies on extra cellular enzymes to make use of polymers for nutrition

Answer 11

Single and multicellular organisms

Question 12

Describe digestion of starch

Answer 12

Begins in mouth to small intestines
Starch polymers are broken down partially into maltose by analyse (produce by pancreatic juice/saliva InMouth)

Maltose is then broken into glucose
Enzyme maltase used.
Glucose absorbed by cell lining to digestive system and absorbed into blood stream

Question 13

Describe digestion of proteins

Answer 13

Trypsin is a protease that catalyses digestion of protein into smaller peptides, which are then broken down into amino acids
Trypsin is produced in prancreas in small intestines where acts as proteins

Amino acids made are absorbed by blood stream of cell lining of digest for system

Question 14

How does temperature affect enzymes

Answer 14

Increase kinetic energy as particles move faster

Question 15

What is temperature coefficient

Answer 15

Measure of how much the rate of reaction increases with a 10c rise in temp.

Question 16

What happens if temperate is too hot in enzyme

Answer 16

Bonds become strained and break, changing tertiary structure
Denature for enzyme

Question 17

What is an optimum temperature of an enzyme?

Answer 17

Enzymes highest activity rate

Question 18

How are enzymes in the metabolic activities, for example, adapted to the cold?

Answer 18

More flexible Structures e.g. At active site- makes less stable than enzymes at higher temperatures

Question 19

How do organisms that are adapted to the cold, denature?

Answer 19

When there are small subtle temperature changes

Question 20

What’s a thermophile

Answer 20

Organism that’s adapted to live in high temperatures like hot springs

Question 21

How do thermophile a survive in high temperatures

Answer 21

More bonds so more stable

E.g more h and sulfar bonds in tertiary structure

Question 22

What does a change in pH often refer to in enzymes

Answer 22

Change in hydrogen ion concentration

Question 23

What is the difference between low and high pH referring to hydrogen ions

Answer 23

Low PH- more hydrogen ions present

High pH- fewer hydrogen ions

Question 24

What is the optimum pH

Answer 24

Had the right shape for active site at a specific hydrogen ion concentration

Question 25

What is renaturation

Answer 25

When the next me becomes too acidic or alkalin, altering the structure But then returns back to the optimum pH and the protein carries on normal shape and catalysing reactions

Question 26

What happens when the pH changes more significantly?

Answer 26

Structure of enzyme irreversible Substrate can't join active site Therefore denatured Reduces rate of reaction

Question 27

What do hydrogen ions react with (pH)

Answer 27

Polar and charged r groups

Question 28

When hydrogens interact with polar and charged R groups, what do they change?

Answer 28

The concentration of hydrogen ions, changing the degree of reaction

Question 29

The more hydrogen ions present, this means less....interact with eachother

Answer 29

R groups

Question 30

From the result of more hydrogen bonds therefore less R groups interacting with eachother, what does this lead too?

Answer 30

Leads to bonds breaking and shape of enzymes changing

Question 31

From the shape changing due to lots of hydrogen ions, when is it more like to be reversible

Answer 31

When there is fewer hydrogen ions present (high pH)

Question 32

Site of action for saliva | PH?

Answer 32

Mouth | 7- neutral

Question 33

What enzyme is in salvia and salvias function

Answer 33

Amylase | Starch I maltose

Question 34

Where's the site of action or gastric juice | pH level?

Answer 34

Stomach | 1-2 acidic

Question 35

Enzyme in gastric juice | Function of gastric juice

Answer 35

Pepsin | Proteins to polypeptides

Question 36

Where's the site of action for pancreatic juice | pH level

Answer 36

Small intestine | 8 slightly alkaline

Question 37

What enzyme is involved in pancreatic juice | What's its function

Answer 37

Trypsin -proteins to polypeptides Maltase- maltose to glucose

Question 38

What happens when the concentration of a substrate is increased?

Answer 38

Number of molecules in particular area increases, therefore more number of substrate particles leading to higher collision rate with active site to form a enzyme-substrate complex.

Question 39

What happens when the enzyme concentration is increased?

Answer 39

More available active sites in an area, leading faster reactions of enzyme-substrate complexes

Question 40

Where does the rate of reaction increase up to

Answer 40

The max known as V max

Question 41

What is v max

Answer 41

Where all active sites are occupied by a substrate molecule and no more can be made.

Question 42

What is a way you could increase reaction when it has reached V max

Answer 42

Add more enzymes or increase temp If Concentration of enzymes increased =more active sites, reaching a higher V max

Question 43

By controlling the activity of enzymes at crucial points in the reaction pathway allows it too...

Answer 43

Regulates the rate and quantity of product formation.

Question 44

What can activate enzymes | What can deactivate them

Answer 44

Cofactors | Inhibitors

Question 45

What are inhibitors

Answer 45

Molecules that prevent enzymes from carrying out function as catalysts

Question 46

What are the two types of inhibitors

Answer 46

Competitive | Non competitive

Question 47

How does a competitive inhibitor work

Answer 47

A molecule that has a similar shape to active site so blocks the substrate from entering it. Enzyme is now inhibited as can't carry out catalyst functions

Question 48

What happens when a substrate and a competitive inhibitor is involved in a solution

Answer 48

Both compete to bind to active site of enzyme, therefore reducing the amount of substrate molecules binding to active site; slowing rate of reaction.

Question 49

Describe competitive inhibitors

Answer 49

Compete for active site | Only temporary so reversible

Question 50

Example of a competitive Inhibitor that ISNT reverisble

Answer 50

Aspirin

Question 51

How does a competitive inhibitor affect the rate of reaction?

Answer 51

Reduces rate of reaction. But doesn't change v max of enzyme it inhibits If substrate concentration is increased enough there will be more substrate than inhibitor so original v max can still be reached

Question 52

Examples of competitive inhibitors

Answer 52

Statins | Aspirin

Question 53

What are statins

Answer 53

Synthesise cholesterol | Prescribed to reduce blood cholesterol concentration

Question 54

Describe aspirin

Answer 54

Inhibits active site of COX enzyme | Prevents synthesis of prostaglandins and thromboxane- chemical that reduces pain and fever

Question 55

How do non competitive inhibitors work

Answer 55

Binds to active site at anywhere but active site. (Allosteric site) The binding causes tertiary structure of enzyme to change, altering shape Substrate can't bind anymore

Question 56

Affect of increasing concentration of enzyme or substrate to overcome non competitive inhibitors

Answer 56

No effect of | Over coming inhibitor

Question 57

What happens if you increase amount of non competitive inhibitors

Answer 57

Decreases rate of reaction as more active sites aren't available

Question 58

Example of non competitive inhibitors

Answer 58

Organophosphates- insecticides- inhibits enzyme for nerve transmission Proton pump inhibitors Used to treat long term indigestion Block enzyme system that secretes hydrogen ions in stomach.

Question 59

What does end product inhibition mean

Answer 59

Term used for enzyme inhibition Occurs when product of a reaction acts as an inhibitor to the enzyme that produce it. - serves as negative feed back control mechanism

Question 60

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Answer 60

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