B3 Organisation And Enzymes

Question 1

What is an enzyme?

Answer 1

A biological catalyst

Question 2

What is a catalyst?

Answer 2

A substance which increases the speed of a reaction, without being changed or used up in the reaction

Question 3

What is the active site?

Answer 3

A unique shape that fits onto the substances involved in a reaction

Question 4

What happens if the substrate does not fit into the active site?

Answer 4

The reaction will not be catalysed

Question 5

What does changing the temperature of an enzyme catalysed reaction do?

Answer 5

Change the rate

Question 6

What initially happens in an enzyme catalysed reaction with an increase in temperature?

Answer 6

The rate increases

Question 7

What happens to an enzyme when the temperature gets too high?

Answer 7

The bonds of the enzymes break
This means the active site changes shape so the substrate does not fit
This is when the enzyme is denatured

Question 8

What is meant by the optimum temperature of an enzyme?

Answer 8

Where the enzyme is most active

this means there are the maximum number of successful collisions between the active site and substrate

Question 9

How does the pH affect enzymes?

Answer 9

If the pH is too high or too low, the bonds are interfered with. This changes the shape of the active site so denatured the enzyme

Question 10

What is meant by the optimum pH?

Answer 10

Where the enzyme is most active.

Question 11

What do you digestive enzymes break down?

Answer 11

A breakdown big molecules into smaller ones

Question 12

Why do digestive enzymes break down molecules?

Answer 12

The broken down molecules smaller and more soluble so they can pass through the digestive system
This is an absorbed into the bloodstream

Question 13

What do carbohydrases breakdown?

Answer 13

Carbohydrates into simple sugars

Question 14

Where is amylase made?

Answer 14

Salivary glands
Pancreas
Small intestine

Question 15

What do proteases breakdown?

Answer 15

Proteins into amino acids

Question 16

Where are proteases made?

Answer 16

Stomach – Pepsin
Pancreas
Small intestine

Question 17

What does lipases convert?

Answer 17

Lipids into glycerol and fatty acids

Question 18

What are lipids?

Answer 18

Fats and oils

Question 19

Where are lipases made?

Answer 19

Pancreas

Small intestine

Question 20

What are the products of digestion used for?

Answer 20

Used to make new carbohydrates, proteins, lipid

Glucose is used for respiration

Question 21

Where is bile produced and stored?

Answer 21

It is produced in the liver

Stored in the gallbladder

Question 22

What does bile do?

Answer 22

It’s neutralises the acid from the stomach to make the enzymes in the small intestine work at optimum pH
It’s emulsifies fats to give them a bigger surface area so the enzymes digest them faster

Question 23

Why is hydrochloric acid produced in the stomach?

Answer 23

To kill bacteria

To give the right pH for protease enzymes

Question 24

What does Benedict’s reagent test for?

Answer 24

Reducing sugars

Question 25

What colour does Benedict’s reagent change in the presence of reducing sugars?

Answer 25

From blue to green, yellow or brick red

Question 26

What does iodine solution test for?

Answer 26

Starches

Question 27

What colour does iodine solution change to?

Answer 27

From browny orange to black or blue black

Question 28

What does biuret’s solution test for?

Answer 28

Proteins

Question 29

What colour does biuret’s solution change to?

Answer 29

From blue to purple

Question 30

What does Sudan III test for?

Answer 30

It stains lipids

Question 31

What colour does Sudan III solution change to?

Answer 31

Two separate layers with the top layer being bright red

Question 32

What are the hazards of food test?

Answer 32

Iodine is an irritant to the eyes | Biuret’s solution is dangerous Sudan three stain solution is flammable

Question 33

What safety precautions should you take during food tests?

Answer 33

Wear goggles Wash chemicals of skin Keep Sudan III stain solution away from Bunsen burners

Question 34

what is a tissue?

Answer 34

a group of cells with a similar structure and function

Question 35

what is an organ?

Answer 35

a group of tissues working together for a specific function

Question 36

what is an organ system?

Answer 36

a group of organs

Question 37

what does the churning action in the stomach do?

Answer 37

turns food into a liquid so it has a larger surface area to digest

Question 38

what is a substrate?

Answer 38

the molecule the enzyme breaks down

Question 39

what are proteins?

Answer 39

long chains of amino acids

Question 40

why does temperature increase the rate of reaction of an enzyme?

Answer 40

as the temperature increases, the enzyme and substrate are moving faster so there are more collisions per second between the enzyme and the substrate

Question 41

what are buffer solutions used for?

Answer 41

to control the pH of a solution in investigations

Question 42

what is the positive result of the ethanol test?

Answer 42

the solution goes from clear to a white cloudy emulsion

Question 43

what are the adaptations of the small intestine?

Answer 43

very long - provides a very large surface area for absorption villi - increases surface area microvilli - increase surface area further good blood supply - increases concentration gradient villi have thin membrane - ensures short diffusion path