BIOLOGY 2B Enzymes

HideShow resource information
  • Created by: CMR71
  • Created on: 25-10-15 17:34
What are enzymes?
They are biological catalysts that reduce the need for high temperatures. Only used for useful chemical reactions in the body.
1 of 40
Whst is a catalyst?
It is a substance which increases the speed of a reaction whitout being changed or used up in the reaction.
2 of 40
What are enzymes made from?
The are proteins, made up of chains of amino acids. These chains are folded into unique shapes, which enzymes need to do their jobs.
3 of 40
What are the other uses of proteins?
They can act as structual components of tissues e.g. muscles, hormones and antibodies.
4 of 40
How many reactions can an enzyme catalyse?
One - key and lock
5 of 40
Why can enzymes only catalyse one reaction?
For the enzyme to work, it has to fit its special shape. If the substances doesnt fit the enzymes shape, then the reaction wont be catalysed.
6 of 40
What do enzymes need to work?
The correct temperature and pH
7 of 40
What happens to an enzyme reaction if you increase the temperature?
Initially it will increase the rate, but if it gets too hot, some of the bonds holding the enzyme together break. This destroys the enzymes special shape and it is said to be denatured.
8 of 40
What is the best temperature for an enzyme to work in the human body?
9 of 40
What is the best pH for an enzyme to work?
Its often neutral pH7 but not always e.g. pepsin is the enzyme used to break down proteins in the stomach. It works best at pH2, which means it is well suited to the acidic conditions
10 of 40
What do digestive enzymes do?
Break down bigger molecules into smaller ones
11 of 40
What are big molecules?
Starch, proteins and fats - these are too big to pass through the walls of the digestive system
12 of 40
What molecules are small enough to pass easily through the walls of the digective system?
Sugars, amino acids, glycerol, and fatty acids
13 of 40
What do the digestive enzymes do?
They break down the bigger molecules into smaller ones
14 of 40
What does Amylase do?
It converts starch into sugars
15 of 40
Where is Amylase produced?
The salivary glands, the pancreas, the small intestine
16 of 40
What does Protease do?
It converts proteins into amino acids
17 of 40
Where is Protease produced?
The stomach (pepsin), the pancreas, the small intestine
18 of 40
What does Lipase do?
It converts lipids into glycerol and fatty acids
19 of 40
Where is Lipase made?
The pancreas, the small intestine
20 of 40
Where is bile made?
Bile is made in the liver and is stored in the gall bladder before being released into the small intestine.
21 of 40
What does bile do?
The hydrochloric acid in the stomach makes it too acidic for the enzymes in the small intestine to work. Bile is alkaline and it neutralises the acid making the conditions more alkaline for the enzymes to work. It also emulsifies fat.
22 of 40
What does emulsify mean?
It means the breaking down of fat into smaller droplets, thereby increasing the surface area for lipase to work and making digestion faster.
23 of 40
What is respiration?
It is the process of releasing energy from glucose which goes on in every cell and is controlled by enzymes
24 of 40
What is aerobic respiration?
It is respiration using oxygen. It is the most efficient way to release energy from glucose. GLUCOSE + OXYGEN = CARBON DIOXIDE + WATER + ENERGY
25 of 40
Where does aerobic respiration happen?
In the mitochondria
26 of 40
What is aerobic respiration used for? 4 examples
1. Build up larger molecules from smaller ones 2. To allow muscles to contract 3. In mammals and birds body temperature steady 4. In plants to build sugars, nitrates etc built upto proteins
27 of 40
What does exercise do to the heart rate?
It increases the heart rate. Muscle cells use oxygen to release energy from glucose which contracts the muscle. Increase in muscle activity requires more glucose and oxygen and carbon dioxide removed. The blood has to flow faster to do this.
28 of 40
What happens in pysical activity?
Your breathing rate increases and makes you breathe more deeply to meet the demand for extra oxygen and increases the speed at which the heart pumps.
29 of 40
How is glycogen used during exercise?
Some glucose from food is stored as glycogen, its mainly stored in the liver but each muscle has its own store. During exercise muscles use glucose rapidly so some stored glycogen is converted back to gluscose to provide more energy.
30 of 40
What is anaerobic respiration?
When your body cant supply enough oxygen to your muscles. It just means without oxygen, its the incomplete breakdown of glucose which produces lactic acid. GLUCOSE = ENERGY + LACTIC ACID
31 of 40
Why is anaerobic respiration not the best way to convert glucose into energy?
Because lactic acid builds up in the muscles which gets painful. It also causes muscle fatigue, the muscles get tired and stop contracting effectively.
32 of 40
Name a disadvantage and an advantage of anaerobic respiration
It does not release as much energy as aerobic (around 5% of the energy released by aerobic) but it does mean you can use your muscles for a bit longer
33 of 40
What is the difference between respiration and breathing?
Respirtation releases energy, breathing lets air in and out of the lungs.
34 of 40
What happens after you have resorted to anaerobic respiration?
You are in oxygen debt- you have to repay the oxygen to your muscles. This means you have to keep breathing hard for a while after you stop to get more oxygen into your blood. Blood flows and removes lactic acid by oxidising it to CO2 and H2O
35 of 40
What does the brain do if it still detects high levels of CO2 and lactic acid?
It will keep your pulse and breathing rate hig to try and rectify the situation.
36 of 40
Is there a difference between being fit and being healthy?
Yes, healthy means free of disease and infection. It is possible to be fit but unhealthy, or healthy but unfit
37 of 40
Name some uses of enzymes
Enzymes are used in biological detergents - proteases and lipases (to break down proteins and fats). Used to change foods - proteases used in some baby foods to 'pre digest' proteins so they are easier for the baby to digest.
38 of 40
What are the advantages of using enzymes in industry?
They are specific, use lower temperatures, lower cost, saves e.nergy. Enzymes work for a long time and biodegradable
39 of 40
What are the disadvantages of using enzymes in industry?
Allergies, some can be denatured by even a small increase in temperature. Susceptible to poisons and pH. Can be expensive to produce and contamination is a risk
40 of 40

Other cards in this set

Card 2


Whst is a catalyst?


It is a substance which increases the speed of a reaction whitout being changed or used up in the reaction.

Card 3


What are enzymes made from?


Preview of the front of card 3

Card 4


What are the other uses of proteins?


Preview of the front of card 4

Card 5


How many reactions can an enzyme catalyse?


Preview of the front of card 5
View more cards



These are very useful and easy to understand, thank you!!


Is there anyway I can save resources so i can use them without internet? 

These are very helpful thankyou.


Very useful and excellent revision tools >.<


nice bruh sum good stuff here


lob123 download the printable pdf

These are really useful thank you so much! 

Similar Biology resources:

See all Biology resources »See all Enzymes and digestion resources »