The Digestive System - Organs And Enzymes (T2)

Question 0

Define digestion..

Answer 0

Digestion is the breakdown of large molecules of food into smaller, soluble molecules of food that can be absorbed into the body and then used. It takes place along the alimentary canal and relies on enzymes.

Question 1

What organs make up the digestive system?

Answer 1

• liver
• gall bladder
• large intestine
• appendix
• oesophagus
• stomach
• pancreas
• small intestine
• rectum
• anus

Question 2

Describe the liver..

Answer 2

• largest organ inside the body.
• makes bile: fluid that helps break down fats and gets rid of waste from the body
• changes food into energy
• cleans alcohol, some medicines and poisons from the blood

Question 3

Describe the gall bladder..

Answer 3

The gall bladder stores the bile made in the liver, then empties it to help digest fats.

Question 4

Describe the large intestine..

Answer 4

• also called the colon

- absorbs water and sodium from the stool

Question 5

Describe the appendix..

Answer 5

• a pouch attached to the first part of the large intestine.

- no known function.

Question 6

Describe the oesophagus..

Answer 6

• carries food from the mouth to the stomach.
• food is forced down by wave-like muscle contractions known as “peristalsis”, which pushes the bolus towards the stomach.

Question 7

Describe the stomach..

Answer 7

The stomach is where the digestion of proteins begins.

Question 8

Describe the pancreas..

Answer 8

The pancreas is a gland that makes enzymes for digestion, and the hormone insulin, which helps turn food into energy.

Question 9

Describe the small intestine..

Answer 9

Where most digestion occurs.

Question 10

Describe the rectum..

Answer 10

The lower end of the large intestine, leading to the anus.

Question 11

Describe the anus..

Answer 11

An opening at the end of the digestive tract where bowel movements leave the body.

Question 12

What are the three most common digestive enzymes and what do they do?

Answer 12

LIPASES
- help to break down fats

PROTEASES
- help to break down proteins

CARBOHYDRASES
- help to break down carbohydrates

Question 13

The enzymes involved in photosynthesis, respiration wind protein synthesis work inside cells and are sometimes known as “intracellular enzymes”.

Digestive enzymes pass out into the gut where they catalyse the break down of food molecules.

What are these enzymes known as?

Answer 13

Extracellular enzymes.

Question 14

Describe the digestive enzyme amylase in detail..

Answer 14

• amylase is produced in the salivary glands, pancreas and small intestine
• it converts starch into sugars
• starch is a very large molecule that contains many glucose molecules joined together
• carbohydrase enzymes break the bonds between sugar molecules to make a small sugar molecule called maltose
• the final stage sees maltose split into glucose for absorption

Eg: when you chew food, amylase is released in the saliva, which starts the digestive process

Question 15

Describe the digestive enzyme protease in detail..

Answer 15

• produced in the stomach, pancreas and small intestine
• converts proteins to amino acids
• proteins are large molecules that contain a long chain of amino acids joined end to end
• sometime also called polypeptides
• Proteases break the bonds between individual amino acids in the protein chain

Question 16

Describe lipase in details..

Answer 16

• produced in the pancreas and small intestine
• converts lipids to fatty acids and glycerol
• fats and oils are made of two types of molecules: fatty acids and glycerol
• the enzyme lipase breaks their bonds apart before they are absorbed in the small intestine