3.2 Human Digestive system

Question 1

What does the mouth do

Answer 1

physically breaks down food into smaller pieces

Question 2

what does the salivary gland do

Answer 2

makes saliva that contains enzymes called amylase

Question 3

What does the gullet do

Answer 3

tube that carries food from throat to stomach

Question 4

What does the stomach do

Answer 4

Organ where food is churned with digestive juices and acids (protease and hydrochloric acid)

Question 5

What does the pancreas do

Answer 5

Makes and releases digestive juices containing the enzymes to break down your food

Question 6

What does the liver do

Answer 6

Produces bile into small intestine where it helps to digest fats

Question 7

What does the gall bladder do

Answer 7

Stores bile

Question 8

Small intestine

Answer 8

where small digested molecules are absorbed into the blood stream

Question 9

Large intestine

Answer 9

Organ where water passes back into body leaving solid waste

Question 10

Anus

Answer 10

Muscular ring opening to get rid of feces

Question 11

Why does the stomach contain acids

Answer 11

Provide the optimum conditions for enzymes to work/kill any microorganisms that may be present in the food

Question 12

What food component does bile digest

Answer 12

Lipids

Question 13

What does the rectum do

Answer 13

Collects your feces until it is time to release it

Question 14

Describe what happens to the structure of food molecules during digestion/ give def of digestion

Answer 14

Large insoluble molecules of food break down into smaller soluble molecules

Question 15

Why cant you absorb food molecules

Answer 15

big , insoluble

Question 16

Give example of glands

Answer 16

pancreas, salivary gland

Question 17

What do the enzymes break down

Answer 17

Large insoluble food molecules into smaller soluble ones

Question 18

How long is normally the digestive system

Answer 18

6-9m

Question 19

Explain how the small intestine is adapted to perform its function

Answer 19

Increase surface area as it is covered in villi
Villi contain blood capillaries to carry away the absorbed food molecules, increase diffusion gradient
These adaptations increase the rate of absorption

Question 20

Digestive system def

Answer 20

Organ system where food is digested and absorbed

Question 21

What is the function of the digestive system

Answer 21

To turn large, insoluble molecules into small, soluble molecules that can be used by the body for energy, growth and repair

Question 22

What does the liver do

Answer 22

It produces bile, which helps in the digestion of lipids

Question 23

Using the digestive system as an example, explain how organs in an organ system rely on each other to function properly

Answer 23

Each part of digestive system relies on preceding parts.
Stomach relies on mouth, teeth, and salivary glands to deliver chunks of
chewed food.
Small intestine depends on stomach to continue digestive process
and on enzymes made by pancreas to help with the digestive process.
Large intestine can only deal with remains of food already digested in
the small intestine (soluble molecules absorbed into blood, leaving
waste material and water),
absorbing water and removing faeces from body.

Question 24

Explain what a protein is

Answer 24

Molecule made up of long chains of amino acids

Question 25

Describe the main similarities and differences between carbohydrates, lipids and proteins

Answer 25

similarities:
• vital components of a balanced diet
• contain carbon, hydrogen, and oxygen
• large molecules made up of smaller molecules joined together
differences:
• carbohydrates made up of sugar units
• lipids made up of fatty acids and glycerol
• proteins made up of long chains of amino acids
• lipids insoluble in water
• proteins contain nitrogen

Question 26

Explain why lipids can either be fats or oils

Answer 26

Lipids are made up of three molecules of fatty acids joined to a
molecule of glycerol.
Different combination of fatty acids
determines whether lipid is solid (fat) or liquid (oil).

Question 27

Explain how simple sugars are related to complex carbohydrates

Answer 27

Complex carbohydrates are made up of long chains of simple sugars
joined together.
Simple sugars are basic units of complex carbohydrates.