Topic 3- Enzymes in digestion

Question 1

Enzymes are substrate specific what does this mean?

Answer 1

different enzymes digest and breakdown the different biological molecules contained in food

Question 2

What are the 3 main types of digestive enzymes?

Answer 2

-carbohydrases
-proteases
-lipases

Question 2

Digestive enzymes are 1._____ enzymes, they work outside of cells

Answer 2

1.extracellular

Question 2

Where does the digestion of carbohydrates take place?

Answer 2

Mouth and small intestine

Question 3

Where is amylase made?

Answer 3

-salivary glands
-the pancreas
-the small intestine

Question 3

What ennzymes hydrolyses carbohydrates into maltose?

Answer 3

Amylose

Question 4

Which enzyme hydrolyses maltose into glucose?

Answer 4

Maltase

Question 5

Where is maltase, sucrase and lactase found?

Answer 5

in cell-surface membranes of the epithelial cells lining the small intestine

Question 6

What do maltase, sucras and lactase allow for?

Answer 6

absorption of monosaccharides into epithelial cells of the small intestine which pass them into the bloodstream

Question 7

Are microvilli present on the surface of the small intrestine?

Answer 7

Yes- Increase SA

Question 8

Where does protein digestion begin?

Answer 8

Lumen of the stomach

Question 9

What is the 1st step of proetin digestion?

Answer 9

endopeptidase hydrolyses peptide bonds creating smaller protein chunks

Question 10

What is endopeptidase secreted along with? What is the function of this?

Answer 10

-Hydrochloric acid
-pH in the stomach is low

Question 11

What is the 2nd step of protein digestion?

Answer 11

partially digested food moves from the stomach into the small intestine

Question 12

What is the 3rd step of protein digestion?

Answer 12

Fluid secreted by the pancreas travels to the small intestine and helps to neutralize the acidic mixture and increase the pH

Question 13

What does the pancreatic juice contain?

Answer 13

Endopeptidases and exopeptidases

Question 14

What is the function of endopeptidases?

Answer 14

hydrolyse peptide bonds within polypeptide chains to produce dipeptides

Question 15

What is the function of exopeptidases/

Answer 15

hydrolyse peptide bonds on the end of polypeptide chains to produce dipeptides

Question 16

there are dipeptidase enzymes found within the cell surface membrane of the epithelial cells in the small intestine, what do these hydrolyse?

Answer 16

dipeptides into amino acids which are released into the cytoplasm of the cell

Question 17

What has to happen before the digestion of lipids?

Answer 17

Emulsification

Question 18

Describe what happens in emulsification

Answer 18

-solid lipids are turned into a fatty liquid consisting of fat droplets
-When the fatty liquid arrives in the small intestine, bile (containing bile salts) (made in the liver,stored in the gallbladder) is secreted
-bile salts bind to the fatty liquid and breaks the fatty droplets into smaller ones via emulsification

Question 19

Why is emulsification useful?

Answer 19

increases the surface area of the fatty droplets for action of digestive enzymes

Question 20

Where does the digestion of lipids take place?

Answer 20

Lumen of the small intestine

Question 21

Where are lipase enzymes produced?

Answer 21

In the pancreas

Question 22

How are lipids digested?

Answer 22

Lipase enzymes break down lipids into glycerol and fatty acids