The digestive system

Question 1

Which enzymes are made in the salivary glands?

Answer 1

Salivary amylase

Question 2

What do salivary amaylse do?

Answer 2

• They hydrolyse the 1-4 and 1-6 glycosidic bonds in starch
• They hydrolyse starch into shorter chains
• This increases the surface area of the molecule

Question 3

What is found in saliva?

Answer 3

Enzymes
Buffer

Question 4

What is a buffer?

Answer 4

It helps maintain the optimum pH

Question 5

What pH does salivary enzymes work best at?

Answer 5

7

Question 6

What enzymes are found in the stomach?

Answer 6

Endopeptidases

Question 7

What does the stomach also produce apart from enzymes?

Answer 7

Hydrochloric acid

Question 8

What do endopeptidases do?

Answer 8

• They hydrolyse the peptide bonds within the peptide chain
• They hydrolyse protein chains into shorter chain polypeptides
• This increases the number of terminal ends, increasing the surface area

Question 9

What pH do endopeptidases work best at?

Answer 9

2

Question 10

What enzymes are found in the pancrease?

Answer 10

Endopeptidases
Exopeptidases
Pancreatic amalyse
Lipase

Question 11

Where are the enzymes in the pancreas delivered to?

Answer 11

They are delivered by the pancreatic to the duodenum

Question 12

What is the duodenum?

Answer 12

The upper part of the small intestine

Question 13

What is bile and where is it made?

Answer 13

Made in the liver and stored in the gall bladder. It acts as an emulsifier and also neutralises the acidic food to pH 8/9

Question 14

What do exopeptidases do?

Answer 14

• Hydrolyse peptide bonds at the terminal ends of the shorter polypeptide chains
• They hydrolyse shorter chains into di-peptides

Question 15

What does pancreatic amylase do?

Answer 15

Hydrolyses shorter chain starch into maltose disacharrides

Question 16

What do lipases do?

Answer 16

• Hydrolyses the ester bond
• Hydrolyses lipids into monoglyceride and 2 fatty acids

Question 17

What enzymes do enzymes from the pancreas work at?

Answer 17

8/9

Question 18

Which enzymes are found in the lower part of the small intestine?

Answer 18

Dipeptidase
Maltase
Sucrase
Lactase

Question 19

What is the lower part of the small intestine known as?

Answer 19

The Ileum

Question 20

Where are the enzymes located in the ileum?

Answer 20

They are embedded in the wall of the ileum

Question 21

What do dipeptidases do?

Answer 21

They hydrolyse dipeptides to 2 amino acids

Question 22

What do maltase do?

Answer 22

Hydrolyse maltase to 2 alpha glucose

Question 23

What do sucrase do?

Answer 23

Hydrolyse sucrose to fructose and alpha glucose

Question 24

What do lactase do?

Answer 24

Hydrolyse galactose and alpha glucose

Question 25

What muscles do the oesphagus have?

Answer 25

It has 2 rings of muscle
- Circular
- Longitudinal
- They are separate

Question 26

How do the 2 rings of muscle in the oesophagus ineract?

Answer 26

They are an antagonistic pair. When one contracts, the other one relaxes
They cause a wave of muscle contraction known as peristalsis

Question 27

What is chewing food known as?

Answer 27

Mastication - it increases the surface area of food and allows it to mix with the saliva

Question 28

What do the salivary glands do?

Answer 28

There are 3 pairs of salivary glands
They produce saliva (which contains enzymes and buffer and antibacterial properties)

Question 29

What is the epiglotis?

Answer 29

Every time you swallow, it closes the pathway to the trachea

Question 30

What happens if food gets stuck by the epiglotis?

Answer 30

If food gets stuck there, the trachea is closed and asphyxia (choking) takes place

Question 31

What is the oesophagus shaped like?

Answer 31

In reality, its more twisted so you cant rely on gravity to pull the food down
So, it has rings of muscle around it that help to propel the food down (peristalsis)