3B-More exchange and transport system

Question 1

hydrolysis reaction

Answer 1

breaks/hydrolyses the chemical bonds between monomers using a water molecule

Question 2

digestion

Answer 2

• large molecules (polymers) are hydrolysed into smaller molecules (monomers) via hydrolysis reactions
• catalysed by specific enzymes
• smaller molecules can be absorbed across cell membranes

Question 3

enzyme to digest carbohydrates

Answer 3

amylase

Question 4

amylase

Answer 4

-catalyses the hydrolysis of starch via breaking/hydrolysing glycosidic bonds in polysaccharides of starch (amylose and amylopectin) into maltose
-secreted by-salivary glands and pancreas for use in small intestine
-

Question 5

hydrolysis of starch carbohydrate

Answer 5

-amylase secreted by salivary glads and pancreas
catalyses the hydrolysis of starch (polysaccharide) into maltose (dipeptide)
-maltose hydrolysed into alpha glucose and alpha glucose and catalysed by maltase (membrane-bound disaccharase)
-alpha glucose absorbed across epithelial cell membrane
-via (Na+) and (glucose) co-transporter protein using ATP for active transport
-

Question 6

amylase made

Answer 6

1-salivary gland

2-pancreas— used in small intestine

Question 7

enzymes and products of hydrolysis of disaccharides

Answer 7

maltose + maltase –> glucose x2
sucrose + sucrase –> fructose and glucose
lactose + lactase —> galactose and glucose

Question 8

membrane bound disaccharidases enzymes

Answer 8

• attached to cell membranes of epithelial cells lining the illeum
• break down disaccharides into monosaccharides

Question 9

Absorption of glucose in ileum of the epithelial cells of the small intestine

Answer 9

1-(Na+) actively transported using energy released from hydrolysis of ATP out of the epithelial cells in the ileum into the blood by (Na+-K+ pump ) co-transport protein
2-creates conc gradient of (Na+) with high conc of (Na+) in the lumen of illeum and low conc of (Na+) inside the epithelial cell
3- causes (Na+) diffuse from lumen of ileum into epithelial cell down conc gradient
4-via sodium-glucose transporter protein
5-carries glucose using energy from Na+ movement down conc gradient from lumen of ileum into epithelial cell
6-conc of glucose increases in epithelial cell
7-glucose diffuses out of epithelial cell into blood down glucose conc gradient
8- via facilitated diffusion via protein channel

Question 10

enzyme to digest lipids

Answer 10

lipase

Question 11

lipase

Answer 11

• lipase catalyses the hydrolysis of lipids via hydrolysing ester bonds via hydrolysis reactions using water into monoglycerides and fatty acids
• made in pancreas for small intestine

Question 12

lipase made

Answer 12

-made in pancreas for small intestine

Question 13

monoglyceride

Answer 13

-glycerol attached to one fatty acid chain

Question 14

digestion of lipids

Answer 14

1-Liver produces bile salts and releases them into small intestine (ileum)
2-bile salts emulsify lipids forming small droplets increasing surface area
3-lipase hydrolyses lipids via hydrolysis of ester bonds using a water molecule forming monglycerides and fatty acids
4-bile salts sticky to monoglycerides and fatty acids forming micelles
5-micelles release monglycerides and fatty acids
6-micelles and monoglycerides are lipid soluble so diffuse across epithelial cell membrane

Question 15

enzymes to digest proteins

Answer 15

1-endopeptidases
2-exopeptidases
3-dipeptidases

Question 16

endopeptidases

Answer 16

hydrolyse peptide bonds WITHIN the proteins polypeptide chains via hydrolysis reaction using water

Question 17

exopeptidases

Answer 17

• hydrolyse peptide bonds at the END of proteins polypeptide chains via hydrolysis reaction using water
• releasing single amino acid

Question 18

dipeptidases

membrane bound dipeptidases on cell-surface membrane of epithelial cells

Answer 18

• hydrolyse peptide bonds in Dipeptides via hydrolysis of dipeptides using water
• membrane bound dipeptidases on epithelial cell of cell surface membrane of small intestine

Question 19

absorption of monosaccharides

Answer 19

1-glucose Na+-glucose co-transporter proteins
2-fructose Na+-glucose facillitated diffusion
3-galactose =Na+-galactose co-transporter proteins

Question 20

absorption of monoglycerides and fatty acids

Answer 20

1-micelles break up
2-release monglycerides and fatty acids
3-lipid soluble diffuse across epithelial cell membrane

Question 21

absorption of amino acids

Answer 21

1- sodium-amino acid co-transporter protein

Question 22

absorption

Answer 22

1-monosaccharides glucose and galactose=co-transport of Na+ (active transport)
fructose= channel protein(facilitated diffusion)
2-monoglycerides and fatty acids= (diffusion)
3- amino acids= co-transport of Na+ (active transport)