Exam 4. Carb digestion

Question 1

Starches

Answer 1

The form we consume the most

Polymer of glucose.

Question 2

Glucose

Answer 2

Smallest absorbable unit of starch
We use it the most for ATP
simple sugar we want

Question 3

Primary enzyme

Answer 3

Amylase

Digest starch into oligosaccharides

Question 4

Secondary enzyme

Answer 4

Dextrinase, glucoamylase, maltase, sucrase, lactase
They take the oligosaccharides into smaller molecules
They act on specific sugars

Question 5

Amylase

Answer 5

Secreted in Saliva and pancreas into the duodenum

Question 6

Enterocyte

Answer 6

Simple columnar epithelium cell of the GI tract

Question 7

Enterocyte Sodium Potassium pump

Answer 7

Located at the basal end
Active transport
More Na outside and more K inside
They defuse down their gradients
A lot of Na leaks inside the cell and a lot of K leaks out of the cell
The pumps forces them against their gradient, moving Na+ out of the cell and K+ into the cell.
This avoid drastic changes of electrolytes inside the cell
This process uses ATP

Question 8

Primary active transport and NA+

Answer 8

As the sodium potassium pump keeps working, the intracellular concentration of sodium decreases.
This process uses ATP to move things against their gradient
There is Na+ in the food we eat, as that hits the lumen there is more Na+ outside the cell, now this Na+ wants to move down its gradient into the cell
This is possible because of the sodium potassium pump that lowers the Na+ concentration even when there is more Na+ outside of the basal end of the enterocyte.

Question 9

How we use Na+ from the lumen to move things into the cell

Answer 9

It has to go though the sodium glucose transporter

It can only go through it if it brings along two glucose molecules

Question 10

SGLT

Answer 10

Sodium glucose transporter

Allows sodium to move into the cell down its gradient

Question 11

Secondary active transport

Answer 11

Using the Na+ sodium gradient to move glucose into the cell
Secondary because we didn’t use ATP, Active because we did use ATP at the primary active transport which allowed the secondary transport to happen

Question 12

G6P

Answer 12

Glucose gets phospolorated into Glucose 6 phosphate as soon as it moves inside the cell.
This allows the cell to maintain its glucose gradient
It can, then, be used by the enterocyte or be move in into the blood

Question 13

Fructose

Answer 13

Fructose can just diffuse in