digestion and absorption

Question 1

digestion

Answer 1

hydrolyisis of large insouluble molecules into smaller molecules that can be absorbed across cell membranes

Question 2

enzymes involved in carbohydrate digestion + where are they found

Answer 2

amylase- mouth

maltase,sucrase,lactase - membrane of SI

Question 3

what are the substrates and products of the carbohydrate digestive enzymes

Answer 3

amylase – starch into smaller polysaccarides
maltase – maltose into 2x glucose
sucrase – sucrose into glucose and fructose
lactase – lactose into glucose and galactose

Question 4

where are lipids digested

Answer 4

SI

Question 5

what needs to happen before lipids can be digested

Answer 5

must be emulsified by bile salts produced in liver - this breaks down large fat molecules into smaller, soluble molecules (MICELLES), increasing SA

Question 6

how are lipids digested

Answer 6

lipase hydrolyses ester bond between monoglycerides and fatty acids

Question 7

enzymes involved in protein digestion + what are their roles

Answer 7

endopeptidases= break between specific AA in middle of polypeptide

exopeptidases= break between specific AA at end of polypeptide

dipeptidases= break dipeptides into AA

Question 8

how are certain molecules absorbed into the ileum despite a -ve conc gradient

Answer 8

co-transport

Question 9

which molecules require co-transport

Answer 9

AA
monosaccharides

Question 11

explain how Na+ ions are involved in co-transport

Answer 11

actively transported out of cell into lumen, creating diffusion gradient. nutients then taken up into the cells alond with Na+ ions

Question 12

why do fatty acids and monoglycerides not require co-transport

Answer 12

the molecules are non-polar, they can easily diffuse across the membrane of the epithelial cells