C3-organisation And The Digestive System

Question 1

What is a tissue?

Answer 1

A group of cells with a similar structure and function

Question 2

What are organs

Answer 2

Organs are collections of tissues performing specific functions

Question 3

What are organs organised into?

Answer 3

Organs are organised into organ systems, which work together to form organisms.

Question 4

What is the function of muscular tissue?

What is the function of glandular tissue?

What is the function of epithelial tissue?

Answer 4

To churn the food and digestive juices of the stomach together

To produce the digestive juices that break down food

Covers the inside and the outside of the organ

Question 5

What is the organisation of large multicellular organisms

Answer 5

Cells
Tissues
Organs
Organ systems
Organism

Question 6

What are the three main nutrients food contains?

Answer 6

Carbohydrates
Lipids
Proteins

Question 7

What happens during digestion

Answer 7

Large food molecules are broken down into small molecules by enzymes. The small molecules can then be absorbed into the bloodstream.

Question 8

What is the first stage of digestion?

Answer 8

First food is chewed in the mouth. Enzymes in the silva begin to digest the starch into smaller sugar molecules

Question 9

What is the function of the œsophagus?

Answer 9

The food passes down the oesophagus into the stomach. In the stomach enzymes begin the digestion of proteins.

The stomach also contains hydrochloride acid which helps the enzymes to digest proteins

Question 10

What does the churning action of the stomach muscles do?

Answer 10

Turns the food into a fluid increasing the surface area for enzymes to digest.

Question 11

What happens after the food is produced into a fluid?

Answer 11

The fluid passes into the small intestine
At this point chemicals are released into the small intestine from the liver and the pancreas
The pancreas releases enzymes which continue the digestion of starch and protein. They also start the digestion of lipids.

The liver produces bile which helps to speed up the digestion of lipids. Bile neutralisés the acid released from the stomach

Thé walls of the small intestine release enzymes to continue the digestion of protein and lipids

Question 12

What happens in the small intestine?

Answer 12

Yeh small food molecules produced by digestion are absorbed I to the bloodstream either by active transport or by diffusion

Question 13

What happens in the large intestine?

Answer 13

Water is absorbed into the bloodstream and the faeces is released from the body

Question 14

What are carbohydrates?

Answer 14

Carbohydrates are made up of units of sugar
Simple sugars are carbohydrates that contain only one or two sugar units- they turn blue Bénédictes solution brick red on heating

Complex carbohydrates contain long chains of simple sugar units bonded together. Starch turns yellow-red iodine solution blue-black.

Question 15

What are lipids?

Answer 15

Lipids consist of three molecules of fatty acids bonded to a molecule of glycerol. The ethanol test indicates the presence of lipids in solutions.

Question 16

What are protein molecules made up of?

Answer 16

Long chains of amino acids. Biuret reagent turns from blue to purple in the presence of proteins.

Question 17

What do catalysts do?

Answer 17

They increase the rate of a chemical reaction without being used up

Question 18

What are enzymes?

Answer 18

Enzymes are proteins that act as biological catalysts - this means they speed up reactions without being used up. An enzyme works on the substrate , forming products. An enzyme’s active site and its substrate are complementary in shape.

Question 19

What is metabolism?

Answer 19

It is the sum of all the reactions in a cell or the body

Question 20

What is an enzymes activity affect by?

Answer 20

The temperature and pH

Height temperatures dénature the enzyme, changing the shape of the active site.
Most human enzymes work best at 37 degrees Celsius

Question 21

What are enzymes that break down carbohydrates called?

What enzyme is starch catalysed by

Answer 21

Carbohydrase

Amylase- amylase is produced in your salivary glands so the digestion of starch starts in your mouth. Amylase is also made in the pancreas but no digestion take place their si all the enzymes made their flow into your small intestine.

Question 22

What are enzymes that break down proteins called?

Answer 22

Protease- they are produced in your stomach your pancreas and your small intestine. The breakdown of proteins into amino acids take place in your stomach and small intestine.

Question 23

What are the lipids that you eat broken down into?

Answer 23

Fatty acids and glycerol in the small intestine.

The reaction is catalysed by lipase enzymes, which are made in your pancreas and you small intestine

Question 24

Where and what are digestive enzymes produced by?

Answer 24

Specialised cells in the glands and in the lining of the digestive system.

Question 25

What does hydrochloride acid give the stomach?

Answer 25

A low pH suitable for the protease se created their to work efficiently.

Question 26

What does alkaline bile do?

Answer 26

Neutralised the acid and gives a high pH for the small intestine to work well

Bile is not an enzyme as it does not break down fat molecules. Instead it emulsifies the fat into tiny droplets which increase the surface area for lipase to increase the rate of digestion.