Enzymes , Enzymes and Digestion Flashcards Preview

Biology B2 > Enzymes , Enzymes and Digestion > Flashcards

Flashcards in Enzymes , Enzymes and Digestion Deck (36):
1

Why to reactions need to be controlled carefully?

To ensure there are the right amount of substances

2

What is one usual way of making a reaction happen faster?
What are the problems with this? (2)

Raise the temperature
It would also speed up the unwanted reactions.
There's a limit to how far the temperature can be raised inside of a living creature without its cells being damaged.

3

Why do living things produce enzymes?

To act as biological catalysts.

4

Enzymes reduce the need for...., and we only have enzymes to speed up the .... reactions in our bodies.

Enzymes reduce the need for high temperatures and we only have enzymes to speed up the useful chemical reactions in our bodies.

5

What is a catalyst?

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

6

What are enzymes made of?
What are these made up of?
How do enzymes do their jobs using the above?

They are made of proteins
These are made of chains of amino acids
They fold into unique shapes to do their particular job.

7

What do proteins do in the body? (used for? 4)

Catalysts
Act as structural components of tissues (muscles)
Hormones
Antibodies

8

Why do enzymes have special shapes?

To catalyse reactions

9

When do things split apart or join together?

In chemical reactions

10

What does every enzyme have?

A unique shape that fits onto another substance in the reaction

11

How many reactions can enzymes typically catalyse?

One

12

Why do enzymes typically catalyse one reaction?

For the enzyme to work they must fit with the substance. If the substance doesn't fit the enzyme's special shape, the reaction won't be catalysed. E.g a key in a lock, they have to fit together to work.

13

Enzymes need just the right conditions to work properly...
They aren't....

They aren't versatile

14

Enzymes need two things...

The right temperature
The right PH

15

Changing the ... and ... changes the rate of an enzyme-catalysed reaction.

The temperature
The PH

16

What effect does the temperature have on the enzyme...
As temperature increases...
Gets too hot...
Effect on the enzyme...
What is the optimum temperature?

The rate of reaction increases.
The enzyme's bonds begin to break, destroying the enzyme's special shape so it no longer works. This is denatured.
The optimum temp where enzymes work the best is 37 in a human , the enzyme is most active, any over it will denature.

17

What effect does the temperature have on the enzyme...
Effect on the enzyme...
What is the optimum PH?

As the levels get to high or too low they interfere with the bonds of the enzyme.
Changes its shape and denatures it.
All have an optimum, sometimes 7, but pepsin used to breakdown proteins in the stomach works best in the acidic pH of the stomach, 2.

18

Where do enzymes work?

Inside and outside cells

19

What do digestive enzymes do to big molecules?

They break them down into smaller ones

20

Give three examples of big molecules, to big to pass through the walls of the digestive system...
How are they made to fit?

Starch
Proteins
Fats
Digestive enzymes break them down into smaller molecules.

21

Give four examples of small molecules, that can pass easily through the walls of the digestive system...

Sugars
Amino acids
Glycerol
Fatty Acids

22

Where are amylase enzymes made? 3
What does they do?

Salivary glands
Pancreas
Small intestine
Converts starch into sugars e.g maltose

23

Where are protease enzymes made? 3
What does they do?

Stomach (called pepsin here)
Pancreas
Small intestine
Converts proteins into amino acids

24

Where are lipase enzymes made? 2
What do they do?

Pancreas
Small intestine
Convert lipids (fats and oils) into glycerol and fatty acids

25

What does bile do?
Where is it produced?

Neutralises the stomach acid in the small intestine and emulsifies fats
In the liver

26

Where is bile stored then released into?

Stored in the gall bladder before it's released into the small intestine.

27

Why is bile needed in the small intestine (acidity)?

The hydrochloric acid from the stomach is too acidic for the enzymes in the small intestine, so the ALKALINE bile is released.
This neutralises the acid and turns the conditions alkaline where the enzymes work best.

28

Why is bile needed? (lipase)

It emulsifies fat!
It breaks it down into tiny droplets and this gives the fat a larger surface area for the enzyme lipase to work on making digestion faster.

29

What catalyses the break down of food?

Enzymes

30

Where are the enzymes produced for the digestive system and what by?

They are produced by specialised cells in glands and the gut lining.

31

Salivary glands produce...

Amylase enzyme in the saliva

32

What does the stomach do? (digestion 3)

Pummels the food with muscular walls
Produces the protease enzyme, pepsin
Produces hydrochloric acid for two reasons...
1. to kill bacteria
2. to give the right pH for the protease enzyme to work - pH2

33

Large intestine does what?

Absorbs excess water.

34

Rectum does what?

stores the mostly undigested food.

35

Small intestine does two things....

Produces lipase and amylase and protease enzymes for digestion.
Absorbs digested food into the blood stream.

36

The pancreas .... does what?

Produces lipase amylase and protease to release into the small intestine.