Absorption of Water soluble molecules

Question 1

What are carbohydrates mainly?

Answer 1

starch and sucrose - dietary ones are glucose polymers, glycogen, cellulose

Question 2

what does amylase do?

Answer 2

break long glucose polymers into smaller glucose chains and disacc maltose

Question 3

Where does starch digestion start?

Answer 3

in the mouth with salivary amylase - then denatured by stomach acid

Question 4

what does pancreatic amylase do?

Answer 4

resumes digestion of starch to maltose

Question 5

What is maltose broken down by?

Answer 5

intestinal brush border enzymes like maltase, sucrase, lactase

Question 6

What are absorbable end products of carb digestion?

Answer 6

glucose, galactose and fructose

Question 7

What is intestinal carb absorption restricted to?

Answer 7

monosaccharides

Question 8

what complex carbs can we digest and not digest?

Answer 8

can - starch and glycogen

cant - cellulose plant fibre and sucralose cant be digested due to chlorine atoms

Question 9

what does intestinal glucose and galactose absorption use?

Answer 9

transports such as NA-glucose symporter and basolateral glut2

Question 10

how does fructose move across the apical membrane?

Answer 10

by facilitated diffusion on glut5 transporter

Question 11

what proteins are least digestible?

Answer 11

plant , egg is most digestible

Question 12

What are enzymes for protein digestion groups called?

Answer 12

endopeptidases and exopeptidases

Question 13

what are endopeptidases?

Answer 13

proteases are zymogens such as pepsin, trpsin and chymotrypsin

Question 14

what are exopeptidases?

Answer 14

digest terminal peptide bonds to release AA - minly isoenzymes of carboxypeptidase

Question 15

what are main products of protein digestion?

Answer 15

free AA, dipeptides, tripeptides

Question 16

what are free AA carried by?

Answer 16

Na dependent cotransport proteins

Question 17

where are di and tri peptides carried to?

Answer 17

enterocytes on oligopeptide transporter pept1

Question 18

what are peptides larger than 3 AA absorbed by?

Answer 18

transcytosis after binding to membrane recepters

Question 19

What is responsible for allergic reactions?

Answer 19

ingested proteins as small peptides can act as antigens

Question 20

in newborns where are peptide absorption take place?

Answer 20

intestinal crypt cells

Question 21

what is a common indigestible peptide drug?

Answer 21

DDAVP synthetic vasopressin

Question 22

what is water soluble vitamins absorbed by?

Answer 22

mediated transport except v b12 as it has cobalt

Question 23

where is intestinal transporter for b12 found?

Answer 23

only in ileum by protein intrinsic factor

Question 24

where is mineral absorption done?

Answer 24

by active transport

Question 25

How is heme iron absorbed?

Answer 25

by apical transporter on enterocyte leves cell on ferroportin

Question 26

how is iron uptake regulated by the body?

Answer 26

by peptide hormone hepcidin

Question 27

how is calcium absorbed?

Answer 27

in gut by passive paracellular pathways - regulated in duodenum by VitD3