B2.3 - Enzymes Flashcards Preview

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Flashcards in B2.3 - Enzymes Deck (47)
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0

What do proteins do?

They act as:
- structural components of tissues
- hormones
- antibodies
-catalysts

1

What is a protein?

A long chain of amino acids.

2

What are enzymes?

Large protein molecules that act as a biological catalyst.

3

How do enzymes work?

-The substrate fits into the active site of the enzyme.
-The enzyme and substrate bind together.
-The reaction takes place rapidly and the products are released from the surface of the enzyme.
-The enzyme is then ready to use again.

4

What do enzymes do?

- Building large molecules from smaller ones.
- Changing one molecule into another.
- Breaking down large molecules into smaller ones.

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5

Why does milk go off?

Enzymes in bacteria break down the protein structure.

6

What are the two main factors that affect enzymes?

-Temperature
-pH level

7

What is the temperature at which most enzymes denature?

40C

8

What is the relationship between temperature and the rate of reactions controlled by enzymes?

As the temperature increases, the rate of reaction increases up to a point.

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9

What is denaturing?

When the temperature is too high, the amino acids unravel therefore changing the shape of the active site rendering the enzyme useless.

10

What is the optimum temperature for human enzymes?

36.5C

11

Where is pepsin found?

The stomach

12

Where is amylase found?

The pancreas

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13

Why does the pH level denature enzymes?

Forces hold the folded chains of amino acids together and a change in pH affects the forces changing the shape of the active site.

14

Why can't enzymes be killed?

They are non-living.

15

What do digestive enzymes do?

They break down large insoluble molecules.

16

What does the stomach do?

It squeezes and breaks up food into smaller pieces with a large surface area. It mixes food with the digestive juices to enable contact with enzymes.

17

Where are enzymes made?

Specialist glands:
- salivary glands
- Pancreas
- Lining of the gut

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18

Which enzymes break down carbohydrates?

Carbohydrases

19

Where is amylase produced?

In the salivary glands and pancreas.

20

Which enzyme breaks down starch?

Amylase

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21

Which enzymes break down proteins?

Proteases

22

Where are proteases produced?

Stomach, pancreas and small intestine.

23

What are proteins broken down into?

Amino acids

24

Which enzymes break down lipids?

Lipases

25

What are lipids broken down into?

Fatty acids and glycerol

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26

Where are lipases produced?

Pancreas and small intestine

27

Why does the stomach contain hydrochloric acid?

The enzymes in the stomach work best at low pH levels.
Bacteria is killed by the acid.

28

What conditions do proteases need?

Alkaline

29

What does bile do?

Neutralises stomach acid and emulsifiers fats.

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