3-B exchange transport systems

Question 1

what is amaylase?

Answer 1

a digestive enzyme that catalyses the breakdown of starch into maltose

Question 2

where is amylase produced and secreted?

Answer 2

produced in salivary glands and pancreas

secreted into mouth and small intestine

Question 3

what are membrane bound disaccharidases?

Answer 3

enzymes attached to membranes of epithelial cells lining ileum
break down disaccharides into monosaccharides

Question 4

which disaccharidases breaks down sucrose maltose and lactose?

Answer 4

sucrose - sucrase- glucose and fructose
maltose-maltase-glucose and glucose
lactose-lactase-glucose and galactose

Question 5

what are lipase enzymes?

Answer 5

catalyse the breakdown of lipids into monoglycerides and fatty acids by hydrolysing water bond

Question 6

where are lipase enzymes produced and secreted?

Answer 6

produced in pancreas

secreted in small intestine

Question 7

what are bile salts?

Answer 7

produced by liver and emulsify lipids into small droplets which have a larger surface area for lipase to work on

Question 8

what are micelles?

Answer 8

include lipase and bile salts
make fatty acids more soluble in water
bring fatty acids to cell lining the ileum where they are absorbed by diffusion

Question 9

what are endopeptidases?

Answer 9

hydrolyse peptide bonds within a protein

Question 10

what are exopeptidases?

Answer 10

hydrolyse peptide bonds at the ends of proteins

Question 11

what are dipeptidases?

Answer 11

exopeptidases that work on dipeptides hydrolysing the peptide bond between two amino acids

Question 12

how are monosaccharides absorbed?

Answer 12

glucose is absorbed by active transport with Na+ via a co transporter
galactose is absorbed using a co transporter
fructose is absorbed by facilitated diffusion

Question 13

how are monoglycerides and fatty acids absorbed?

Answer 13

micelles move them to epithelial cell membranes where they are absorbed

Question 14

how are amino acids absorbed?

Answer 14

sodium ions are actively transported out of the epithelial cells into ilium and diffuse back through sodium dependent transporter proteins carrying amino acids with them

Question 15

what is haemoglobin’s role?

Answer 15

carry oxygen around the body

Question 16

what is thr structure of Haemoglobin?

Answer 16

quaternary structure 
4 polypeptide chains 
each chain has a haem group 
each haem group has an iron ion 
can carry 4 O2

Question 17

what is the reaction for the formation and dissociation of oxyhaemoglobin?

Answer 17

Hb + 4O2 HbO8

Question 18

what is the affinity of oxygen?

Answer 18

tendency a molecule has to bind to oxygen