digestion

Question 1

digestion

Answer 1

breakdown of complex molecules into simple molecules

Question 2

absorption

Answer 2

transporting simple molecules across intestinal epithelium

Question 3

in order for nutrients to be absorbed in SI much be transported across apical (ie luminal) surface of

Answer 3

enterocytes

then across basolateral surface of cell

Question 4

apical (luminal) surface of enterocytes covered in

Answer 4

microvilli

Question 5

before nutrients can reach the apical surface of enterocytes of SI, what do they have to diffuse through

Answer 5

glycocalyx; jelly-like layer of glycoprotein

Question 6

what is attached to microvilli of enterocytes

Answer 6

digestive enzymes and proteins; project into glycocalyx

Question 7

goblet cells between enterocytes produce

Answer 7

mucous

Question 8

fluid flows slower where

Answer 8

closer to intestinal surface; ie unstirred water layer (think like a river, faster in middle, slower at banks)

Question 9

what is the diffusion barrier nutrients must pass through before getting absorbed

Answer 9

unstirred water layer, mucous and glycocalyx

Question 10

why is physical digestion (breakdown of particle size) important

Answer 10

• allows food to pass through GI tract
• increases SA exposed to digestive enzymes

Question 11

what does physical digestion begin and end

Answer 11

mastication

ends in distal stomach by grinding action near pylorus (aided by breakdown of connective tissue by HCl and pepsin)

Question 12

chemical digestion of each major nutrient is achieved through the process of

Answer 12

hydrolysis; splitting of a chemical bond by the insertion of a water molecule

Question 13

what bond is hydrolyzed in digestion of carbs

Answer 13

glycosidic bond

Question 14

what bond is hydrolyzed in digestion of proteins

Answer 14

peptide bond