P1 - Organisation

Question 1

3Why are muscle cells packed full of mitochondria?

Answer 1

To provide the energy needed for contraction

Question 2

What’s a tissue?

Answer 2

A tissue is a group of cells with a similar structure and function

Question 3

What’s an organ?

Answer 3

An organ is a group of tissues working together for a specific function

Question 4

What 2 tissues does the stomach contain which release enzymes?

Answer 4

• Muscle tissue
• Glandular tissue

Question 5

What’s an organ system?

Answer 5

A group of organs

Question 6

What’s an organism?

Answer 6

A group of organ systems

Question 7

What are the 3 main nutrients that food contains?

Answer 7

• Carbohydrates
• Protein
• Lipids

Question 8

TRUE OR FALSE: Carbohydrates, protein and lipids are small enough to be absorbed into the bloodstream

Answer 8

FALSE: Carbohydrates, protein and lipids are large molecules that have to be digested

Question 9

Once large food molecules are broken down, what happens?

Answer 9

They’re broken down into small molecules by enzymes and are absorbed into the bloodstream

Question 10

What’s the function of the mouth in the digestive system?

Answer 10

To chew food and the enzymes in the saliva begin to digest the starch into smaller sugar molecules

Question 11

What’s the function of the oesophagus?

Answer 11

To pass food from the mouth to the stomach

Question 12

What’s the function of the stomach?

Answer 12

• To digest proteins with enzymes

Question 13

What does the hydrochloric acid in the stomach do?

Answer 13

Helps the enzymes to digest proteins

Question 14

How long does food spend in the stomach?

Answer 14

Several hours

Question 15

What does the churning action of the stomach muscles do?

Answer 15

Turns the food into a fluid which increases the surface area for enzymes to digest

Question 16

What’s the function of the small intestine?

Answer 16

To absorb small food molecules into the bloodstream by diffusion or active transport

Question 17

Chemicals are released into the small intestine, where do they come from?

Answer 17

The liver and the pancreas

Question 18

What’s the function of the pancreas in the digestive system?

Answer 18

The pancreas releases enzymes which continue the digestion of starch and protein and start the digestion of lipids

Question 19

What’s the function of the liver in the digestive system?

Answer 19

The liver releases bile

Question 20

What are 2 functions of bile?

Answer 20

• Speeds up the digestion of lipids
• Neutralises the acid released from the stomach

Question 21

What does the walls of the small intestine release during the digestive system?

Answer 21

Enzymes to continue the digestion of protein and lipids

Question 22

What’s the function of the large intestine?

Answer 22

To absorb water into the bloodstream

Question 23

What happens at the end of the digestive system?

Answer 23

Faeces are released from the body

Question 24

What are the products of digestion used for?

Answer 24

To build new carbohydrates, lipids and proteins

Question 25

Large food molecules are digested by enzymes into what?

Answer 25

Smaller molecules

Question 26

Do enzymes speed up or slow down chemical reactions?

Answer 26

Speed up

Question 27

What's the active site of an enzyme?

Answer 27

It's where the 3 attaches to

Question 28

What's the substrate?

Answer 28

The molecule the enzymes breaks down

Question 29

What's the theory that suggests the substrate must fit perfectly into the active site in enzymes?

Answer 29

The lock and key theory

Question 30

What breaks proteins down?

Answer 30

Protease

Question 31

Where is protease found?

Answer 31

- Stomach - Pancreatic fluid - Small intestine

Question 32

Proteins are long chains of chemicals called what?

Answer 32

Amino acids

Question 33

When we digest proteins, protease converts the protein back to what?

Answer 33

Invdividual amino acids Extra: They're then absorbed into the bloodstream

Question 34

When amino acids are absorbed by the body cells, they are joined together in a different order to make what?

Answer 34

Human proteins

Question 35

What does starch consist of ?

Answer 35

A chain of glucose molecules

Question 36

What breaks carbohydrates down?

Answer 36

Carbohydrase

Question 37

In the case of starch, what enzyme breaks it down?

Answer 37

Amylase

Question 38

When carbohydrates are digested, what do we produce?

Answer 38

Simple sugars

Question 39

Where is amylase found?

Answer 39

- Saliva - Pancreatic fluid

Question 40

What does a lipid molecule consist of?

Answer 40

Glycerol attached to three molecules of fatty acids

Question 41

What breaks lipids down? Then what does it produce?

Answer 41

Lipase, it produces glycerol and fatty acids

Question 42

Where do we find lipase?

Answer 42

- Pancreatic fluid - Small intestine

Question 43

Where is bile made and stored?

Answer 43

Made in the liver Stored in the gall bladder

Question 44

TRUE OR FALSE: Bile is an enzyme

Answer 44

FALSE: Bile is not an enzyme

Question 45

When bile emulsifies the lipid, how does it affect the surface area of the lipid droplets? How does this affect the rate of lipid breakdown by lipase?

Answer 45

It increases the surface area It increases the rate of lipid breakdown by lipase

Question 46

Why does temperature increase increase the activity of the enzyme aka the reaction gets faster?

Answer 46

As the temperature increases, the enzyme and substrate are moving faster so there are more collisions per second between the substrate and the active site

Question 47

What is it called when the enzyme is working at its fastest possible rate? What effect does this have on on collisions?

Answer 47

Optimum temperature, there's now the maximum frequency of successful collisions between the substrate and the active site

Question 48

What happens when temperature is increased past the optimum for enzymes?

Answer 48

The activity of the enzyme rapidly decreases to 0 aka it stops working

Question 49

Why do enzymes stop working past the optimum temperature?

Answer 49

At high temperatures, the enzyme molecule vibrates and the shape of the active site changes therefore the substrate no longer fits into the active site

Question 50

When a substrate no longer fits into an active site because the enzyme has experienced high temperatures, what do we call the active site?

Answer 50

The active site is denatured, the enzyme can no longer catalyse the reaction

Question 51

For enzymes, what happens if the pH is more acidic or more alkaline? Why does this happen?

Answer 51

The activitiy drops to 0 because the active site denatures if the conditions are too acidic or too alkaline

Question 52

What's an example of an enzyme that works best at an acidic pH?

Answer 52

Protease enzyme (in the stomach)

Question 53

What's an example of an enzyme that works best at an alkaline pH?

Answer 53

Lipase enzyme (released from the pancreas into the small intestine)