B6.9-10 Human Digestion & Absorption

Question 1

Digestion of starch

Answer 1

Starch -> Maltose via amylase
Maltose -> 2x Glucose via maltase

Question 2

1st step in the digestion of protein

Answer 2

Protein -> Polypeptides via endopeptidase
(Central bonds are hydrolysed)

Question 3

Protein -> Polypeptides via endopeptidase
(Central bonds are hydrolysed)
What is the next step of digestion

Answer 3

Polypeptides -> Dipeptides via exopeptidase
(End bonds are hydrolysed)

Question 4

Polypeptides -> Dipeptides via exopeptidase
(End bonds are hydrolysed)
What is the next step of digestion

Answer 4

Dipeptides -> Amino Acids via dipeptidase

Question 5

First step of lipid digestion

Answer 5

Lipids and bile salts undergo emulsification to form micelles

Question 6

Lipids and bile salts undergo emulsification to form micelles
What is the next step of lipid digestion

Answer 6

Micelles are hydrolysed by lipase to form glycerol and fatty acids

Question 7

How are amino acids/monosaccharides absorbed?

Answer 7

X = A Specific monosaccharide or amino acid

X is co-transported with Na+ into the epithelial cell

X moves into the blood via facilitated diffusion

Question 8

Important of the Sodium-potassium pump

Answer 8

The sodium-potassium pump uses ATP to move sodium out of the cell to maintain concentration gradient

Question 9

First step in the absorption of lipids

Answer 9

Bile salts form micelles with monoglycerides and fatty acids which take them to the surface of the epithelial cells

Question 10

Bile salts form micelles with monoglycerides and fatty acids which take them to the surface of the epithelial cells
What is the next step of lipid absorption?

Answer 10

Monoglycerides and fatty acids move into the epithelial cells via simple diffusion

Question 11

Monoglycerides and fatty acids move into the epithelial cells via simple diffusion
What is the next step of lipid absorption

Answer 11

The SER turns monoglycerides and fatty acids into Triglycerides

Question 12

The SER turns monoglycerides and fatty acids into Triglycerides
What is the next step of lipid absorption

Answer 12

The SER and golgi apparatus turns triglycerides, proteins and cholesterol into chylomicrons

Question 13

The SER and golgi apparatus turns triglycerides, proteins and cholesterol into chylomicrons
What is the next step of lipid absorption

Answer 13

Chylomicrons move out of the epithelial cell and into the lymphatic system via exocytosis