Digestion and Absorption

Question 1

Carbohydrates- D

Answer 1

starch is made up of amylopectin and amylose- both made from alpha glucose
amylase catalyses the breakdown of starch
starch to maltose
maltose hydrolysed using maltase into glucose
glucose can pass into cytoplasm of epithelial cell
amylase- pancreas maltase- small intestine

Question 2

Carbohydrates- A

Answer 2

glucose enters epithelial cells by glucose Na+ co trasnporter from lumen
Na+ removed from cell by active transport with potassium (into blood)
low conc of sodium in cell maintaining conc gradient for glucose Na co transporter
glucose moves into blood by facilitated diffusion
ATP needed due to active transport

Question 3

Proteins- D

Answer 3

begins in lumen by protease enzymes
peptide bonds hydrolysed
endopeptidases- hydrolyse peptide bonds within protein
- produce shorter polypeptides
- stomach, pancreas
exopeptidases- hydrolyse peptide bonds at end of protein
- produce amino acids or dipeptides
- pancreas
dipeptidases- hydrolyse dipeptides to produce single amino acids
- often located on cell surface of epithelial cells
- small intestine

Question 4

Proteins- A

Answer 4

Na+ amino acid pump/ co transporter works in same way

Question 5

Lipids- D

Answer 5

solid lipids into fatty liquid- consists of fat droplets
bile salts bind to fatty acid and break fatty acids into smaller ones via emulsification
emulsification increases SA of fatty droplets for enzymes
lipase enzymes break down lipids to glycerol and fatty acids
micelles help products be absorbed

Question 6

Lipids- A

Answer 6

monoglycerides and fatty acids combine with tryglicerdies and bile salts to form micelles
micelles break down fatty acids and monoglycerides and carry them to cell to enter epithelial cells by diffusion
triglycerides formed in RER/ golgi appratus
combine with proteins and packages into chlyomicrons
enter bloodstream