digestion of carbs, lipids and proteins

Question 1

describe carbohydrate digestion

Answer 1

digestion of carbohydrates starts in the mouth.

• Salivary glands secrete α–amylase. Breaks the bonds between the glucose units in starch. Breaks amylose & amylopectin into smaller chains of glucose: dextrins
• The branched amylopectin is digested into maltotriose, maltose and dextrins

Question 2

describe protein digestion

Answer 2

Proteins must be broken down into amino acids before they’re absorbed.

HCL facilitates the denaturation of proteins and lowers the pH to 3.5. This stimulates pepsinogen into active pepsin enzyme.

-Pepsin breaks the peptide bonds and dismantles the protein chains into smaller and smaller fragments

Question 3

describe intestinal protein digestion

Answer 3

two phases: luminal and brush boarder

luminal phase: Proteases are synthesized in the pancreas and secreted into the lumen

brush border phase: Brush border phase. Tripeptides, dipeptides, and single amino acids enter the enterocytes using active transport. These are then broken down to single amino acids, absorbed into blood. Amino acids that are not absorbed are excreted into feces.

Question 4

describe lipid digestion

Answer 4

lingual phase: produced by cells on the tongue. Clears fatty acids from the glycerol backbone

Gastric lipase: produced contributes to enzymatic digestion of triglycerides

Question 5

what is the function of bile in lipid digestion

Answer 5

has hydrophobic and hydrophilic properties. Bile emulsifys lipids because they are then more accessible to digestive enzymes