1.4 Enzymes

Question 1

What is an enzyme

Answer 1

A protein
A biological catalyst
Specific to one substrate

Question 2

What is the name given to the part of the enzyme that the substrate will bind to

Answer 2

The Active site

Question 3

What is the term used to describe how the shape of the active site fits the substrate

Answer 3

Complementary

Question 4

What is the name of the model used to describe how the substrate fits the enzyme

Answer 4

Lock and Key model

Question 5

In the lock and key model what is the lock representing and the key representing

Answer 5

Lock - Enzyme
Key - substrate

Question 6

What is the term used to describe the maximum rate of enzyme activity

Answer 6

Optimum

Question 7

When measuring the rate of an enzyme reaction what 2 things need to be measured

Answer 7

Time
Amount of substrate used OR amount of product made

Question 8

Describe the effect of temperature on an enzyme reaction

Answer 8

At low temperature rate of reaction is low
As increase temperature enzyme and substrate gain kinetic energy
More (successful) collisions and more enzyme-substrate complexes formed
More product produced

Question 9

What happens if the temperature is too high to an enzyme reaction

Answer 9

The reaction will decrease rapidly - the enzymes become denatured and cannot function

Question 10

What is denaturation

Answer 10

The enzyme shape has changed which means active site shape is changed
Can no longer form Enzyme-substrate complexes as no longer complementary to enzyme
Substrate cannot be broken down

Question 11

How does pH affect enzyme activity

Answer 11

Enzymes have a specific pH that is their optimum pH
Above or below that pH the enzyme becomes denatured and rate of reaction decreases

Question 12

What happens in a reaction if the enzyme concentration increases

Answer 12

The rate of reaction will initially increase as more enzymes available - more active sites so more Enzyme substrate complexes can form - more product produced.
At a certain point there is an excess of enzymes so not enough substrate to bind to all the available active sites - the rate of reaction will level out and remain constant

Question 13

What is an inhibitor

Answer 13

A molecule that has a shape similar to the substrate and can fit the active site of the enzyme. IT will prevent the substrate binding so no product forms
The more inhibitors present the less product produced as less available active sites

Question 14

What are the three enzymes used in digestion

Answer 14

Amylase (carbohydrase)
Lipase
Protease

Question 15

Where in digestive system is amylase produced

Answer 15

Saliva
Pancreas
Small intestine (duodenum)

Question 16

Where in the digestive system in protease produced

Answer 16

Stomach
Pancreas
Small intestine (duodenum)

Question 17

Where in the digestive system is lipase produced

Answer 17

Pancreas
Small intestine (duodenum)

Question 18

What is the substrate and product formed using enzyme amylase

Answer 18

Substrate - carbohydrate (starch)
Product - sugars

Question 19

What is the substrate and product formed using enzyme protease

Answer 19

Substrate - protein
Product - amino acids

Question 20

What is the substrate and product formed using enzyme lipase

Answer 20

Substrate - lipids (fat)
Product - fatty acid AND glycerol need both

Question 21

Where in the digestive system do materials from digestion get absorbed

Answer 21

Ileum

Question 22

What adaptations does the ileum have to allow absorption

Answer 22

Have folds called Villi

Question 23

How do the villi allow absorption to occur

Answer 23

They have thin walls - short distance for diffusion
They have moist surfaces - diffusion happens more quickly
They have a good blood supply to take away the digested food so maintain concentration gradient
They have a large surface area

Question 24

What is at the centre of the villi and its role

Answer 24

Lacteals
They absorb and transport fatty acids and glycerol away from small intestine in lymph

Question 25

Where does digested food go to first after leaving the small intestine

Answer 25

Liver

Question 26

WHat is the name of the blood vessel that transports food to the liver

Answer 26

Hepatic Portal Vein

Question 27

Give an example of where enzymes are used commercially

Answer 27

Biological Washing powder

Question 28

What are the advantages of using biological washing powder

Answer 28

Wash at lower temperature - less fossil fuels used to make electricity - better for environment and cost less (economic benefit)