Digestion, Absorption, Transport Of Carbs

Question 1

Starch

Answer 1

Alpha-D-glucose
Alpha-1,4 and alpha-1,6 glycosidic bonds
Amylose and amylopectin
Storage in plants

Question 2

Glycogen

Answer 2

Storage in animals
Alpha-D-glucose
Alpha-1,4 and alpha-1,6 glycosidic bonds

Question 3

Cellulose

Answer 3

Beta-D-glucose
Beta-1,4 bonds
Unbranched

Question 4

Sucrose

Answer 4

Glucose and Fructose
Alpha, beta-1,2 glycosidic bond
Non reducing

Question 5

Lactose

Answer 5

Galactose and Glucose
Beta-1,4 bond
Reducing

Question 6

Trehalose

Answer 6

Glucose and Glucose
Alpha, alpha-1,1
Non reducing

Question 7

What does digestion do?

Answer 7

Turn poly and disaccharides into their monosaccharides

Question 8

Where is amylase found?

Answer 8

Saliva and pancreas

Question 9

Salivary alpha amylase

Answer 9

Hydrolyzes interior alpha 1 4 bonds, breaking down starch and glycogen into maltose, maltotriose, and alpha-dextrins

Question 10

What does lactase do?

Answer 10

Cleave lactose into galactose and glucose

Question 11

What does trehalase do?

Answer 11

Cleave trehalose into 2 glucoses

Question 12

What does sucrase do?

Answer 12

Cleave sucrose into fructose and glucose

Question 13

What does sucrose isoamylase do?

Answer 13

Cleave maltose into 2 glucoses
Sucrase site - hydrolyzes sucrose to glucose and fructose with maltase activity
Isomaltase site - hydrolyzes alpha 1-6 bt glucose residues with maltase activity

Question 14

What does glucoamylase do?

Answer 14

Cleave maltose into 2 glucose

Cleaves at NR end, one glucose molecule at a time

Question 15

What does isomaltase do?

Answer 15

Cleave isomaltose into 2 glucoses

Question 16

How does fiber get broken down and what does it get broken down into?

Answer 16

Colonic bacteria make it more soluble by converting it to gas, short chain fatty acids, and lactase

Question 17

Glycosidase does what?

Answer 17

Hydrolyze glycosidic bonds

Question 18

Salivary alpha-amylases do what?

Answer 18

Hydrolyze interior alpha 1-4 bonds bt glucose in amylopectin, amylose, and glycogen into smaller entities

Question 19

What happens in the luminal phase?

Answer 19

Intestinal epithelial cells produce cholecystokinin (releases pancreatic alpha amylase) and secretin (releases bicarbonate that neutralizes intestinal pH)

Question 20

What happens in membrane phase?

Answer 20

Lactose, maltose, sucrose, maltotriose, and alpha dextrins are broken down from the NR end 1 monosaccharide at a time

Question 21

Glycemic index

Answer 21

Indicates how fast blood glucose levels rise after consumption

Question 22

What happens in lactose intolerant people’s intestines?

Answer 22

Undirected lactose get into large intestine, water is drawn into large intestine, bacteria ferments lactose to lactate and gas, causing symptoms

Question 23

SGLT proteins

Answer 23

Sodium dependent transporter
Active transport
Galactose and glucose

Question 24

Major carb constituents in U.S.

Answer 24

Starch, sucrose, lactose

Question 25

Glut1

Answer 25

RBCs, blood brain barrier

Expressed in cell types with barrier functions

Question 26

Glut2

Answer 26

Liver, pancreatic beta cells, contraluminal memb of intestinal cells
Accepts all 3 monosaccharides
Transfers from intestinal lumen to circulation

Question 27

Glut3

Answer 27

Brain (neurons)

Transporter in CNS

Question 28

Glut4

Answer 28

Adipose tissue, skeletal muscle, heart muscle

Insulin sensitive transporter

Question 29

Glut5

Answer 29

Intestinal epithelial cells, sperm
Fructose transporter
Facilitated diffusion

Question 30

Sglt1

Answer 30

Intestinal epithelial cells
Glucose and galactose
Active transport

Question 31

Sglt2

Answer 31

Kidney

Question 32

Difference between galactose and glucose

Answer 32

Galactose has hydroxyl in beta position, glucose has it in the alpha

Question 33

Alpha position

Answer 33

Down