B3 - Organisation and the Digestive System

Question 1

food test for glucose

Answer 1

Benedict’s solution turns brick red when glucose is present

Question 2

define tissue

Answer 2

a group of similar cells working together to perform a specific function

Question 3

define organ

Answer 3

a group of different tissues working together to perform a specific function

Question 4

define organ system

Answer 4

a group of organs working together to perform a specific function

Question 5

list the hierarchy of things that make up an organism

smallest -> largest

Answer 5

• organelles
• cells
• tissues
• organs
• organ systems
• organism

Question 6

What is the function of the liver?

Answer 6

producing bile

Question 7

What is the function of the stomach?

Answer 7

Breaking down large insoluble molecules into smaller soluble molecules

Question 8

What is the function of the small intestine?

Answer 8

Breaking down large insoluble molecules into smaller soluble molecules
And absorbing food

Question 9

What is the function of the large intestine?

Answer 9

absorbing water from undigested food

Question 10

an example of an enzyme that breaks down carbohydrates - what is the product

Answer 10

amylase (a carbohydrase) - it breaks carbohydrates into simple sugars

Question 11

an example of an enzyme that breaks down proteins - what is the product

Answer 11

pepsin (a protease) - amino acids

Question 12

what is the name of the enzymes that break down lipids - what is the product

Answer 12

lipase enzymes - fatty acids and glycerol

Question 13

Where is amylase produced?

Answer 13

• salivary glands
• small intestine
• pancreas

Question 14

Where is pepsin produced?

Answer 14

• gastric glands in stomach
• small intestine
• pancreas

Question 15

Where is lipase produced?

Answer 15

• small intestine
• pancreas

Question 16

define metabolism

Answer 16

the sum of all the reactions in the cell or the body

Question 17

what are enzymes

Answer 17

they are organic catalysts that speed up reactions

Question 18

define exothermic reaction

Answer 18

transfers energy to the surroundings

Question 19

define endothermic reaction

Answer 19

transfers energy from the surroundings

Question 20

what does it mean if an enzyme is denatured

Answer 20

the active site of the enzyme changes shape so it can no longer catalyse reactions

Question 21

lock and key interpretation of enzyme action

Answer 21

1. the enzyme has a specific active site that binds with the substrate, like a key.
2. the active site is complementary to the substrate - the fit is exact
3. enzymes are specific meaning they catalyse a specific reaction

Question 22

define quantitative and qualitative

Answer 22

quantitative - can be measured
qualitative - cannot be measured

Question 23

define optimum condition of an enzyme

Answer 23

the temperature and pH of which a specific enzyme catalyses the most reactions

Question 24

2 functions of bile

Answer 24

• emulsifies fat to form smaller droplets to increase surface area for enzyme catalysation
• neutralises stomach acid (8 pH)

Question 25

where is bile stored

Answer 25

gallbladder

Question 26

How do you test for sugar?

Answer 26

Get a test tube and add a few bits of the food you're testing on into it. Then add a few drops of **benedict's solution** into it. After place in a controlled heated water bath . Wait for 5 minutes then take it out. If the colour changes from **blue** to **brick-red, green or yellow** then sugar is present depending on how much sugar there is.

Question 27

How do you test for starch?

Answer 27

Take a test tube and add your food sample into it with a few drops of **iodine solution**. Then gently shake it and if the solution turns from **yellow-brown** to **black** or blue-black then starch is present

Question 28

How do you test for lipids?

Answer 28

Get a test tube and put a sample of the food you're testing on. Then use a pipette to add **ethanol** into the test tube. If the solution turns from **clear** to **cloudy white** then lipids are present.

Question 29

How do you test for protein?

Answer 29

Add a few drops of the food and **biuret reagent** into a test tube. Then mix the solutions up by gently shaking it. If protein is present then it'll change from **blue** to **purple**.