B3 - Tissues And Organ Systems

Question 1

Enzymes

Answer 1

Special biological catalysts that speed up reactions.

Question 2

Different enzymes have ___ optimum ___.

Answer 2

optimum , pHs

Question 3

Calculation for rate of an enzyme-controlled reaction

Answer 3

1 / Time taken for end point to be reached

Question 4

What does the rate of an enzyme-controlled reaction mean?

Answer 4

How quickly a reaction occurs.

Question 5

Comparing the rates of reactions taking place under different conditions can enable you to …

Answer 5

determine the optimum conditions for an enzyme.

Question 6

Carbohydrates are made up of …

Answer 6

units of sugar

Question 7

Simple sugars

Answer 7

Carbohydrates containing only one or two sugar units.

Question 8

Carbohydrates and Benedict’s solution

Answer 8

Carbohydrates turn blue Benedict’s solution brick red on heating.

Question 9

Consistency of Lipids

Answer 9

Three molecules of fatty acids bonded to a molecule of glycerol.

Question 10

Lipids and Ethanol

Answer 10

Ethanol test indicates the presence of lipids in solutions.

Question 11

Consistency of Protein

Answer 11

Molecules made from long chains of amino acids.

Question 12

Protein and Biuret reagent

Answer 12

Protein turns Biuret reagent from blue to purple.

Question 13

What is a catalyst?

Answer 13

A substance that increases the rate of chemical reactions without being used up.

Question 14

What are Enzymes, exactly?

Answer 14

Proteins. They fold their amino acid chains into an active site, which matches the shape of a specific substrate.

Question 15

The ___ binds to the ___ ___ and the reaction is ___ by the ___

Answer 15

The SUBSTRATE binds to the ACTIVE SITE and the reaction is CATALYSED by the ENZYME.

Question 16

What is metabolism

Answer 16

The sum of all the reactions in a cell or in the body.

Question 17

Factors affecting enzyme activity

Answer 17

Temperature and pH

Question 18

Effect of high temperatures on an enzyme

Answer 18

High temperatures denature the enzyme, changing the shape of the active site.

Question 19

Effect of pH on an enzyme

Answer 19

pH can affect an enzyme’s active site and make it work either very efficiently or stop it working altogether.

Question 20

[True or False] Enzymes are killed when conditions surpass either their optimum temperature or pH

Answer 20

False

Enzymes are molecules, not living things themselves. Instead, they denature past their optimum temperature and/or pH.

Question 21

What does digestion involve?

Answer 21

Involves the breakdown of large insoluble molecules into soluble substances that can be absorbed into the bloodstream across the wall of the small intestine.

Question 22

How digestive enzymes are produced

Answer 22

By specialised cells in glands and in the digestive system lining.

Question 23

Effect of amylase on carbohydrates

Answer 23

Catalyses the breakdown of carbohydrates to simple sugars.

Question 24

Effect of protease on protein

Answer 24

Catalyses breakdown of protein to amino acids.

Question 25

Effect of lipase on lipids

Answer 25

Catalyses breakdown of lipids to glycerol and fatty acids.

Question 26

Purpose of Hydrochloric acid in the stomach

Answer 26

It gives the suitable pH conditions for protease secreted in the stomach to work efficiently during digestion.

Question 27

Purpose of alkaline bile in digestion

Answer 27

Neutralises the hydrochloric acid and gives ideal pH conditions for the enzymes from the pancreas and small intestine to work well during digestion.

Question 28

[True or False] Bile is an enzyme because it breaks down fat molecules.

Answer 28

False. It EMULSIFIES fat molecules into tiny droplets, increasing the surface area for lipase to increase the rate of digestion.