Transport Of Glucose

Question 1

Tight junction function

Answer 1

Forms a fence - prevents membrane proteins from diffusing in plane of lipid bilayer
Acts as a barrier (restricts movement of substances through intercellular space)

Question 2

Apical and Basal

Answer 2

Apical - membrane that faces lumen of organ or body cavity

Basal - membrane that adheres to adjacent basement membrane and interfaces with blood

Question 3

2 types of transport

Answer 3

Para cellular - through para cellular space between junctions
Trans cellular - through cytoplasm of a cell

Question 4

Para classification

Answer 4

Only can move stuff by what’s going on with the gradient and the tightness of the junction
Higher electrical resistance = more tight strands holding cell

Question 5

What’s leaky epithelium

Answer 5

Low electrical resistance, lots of transport occurring via para cellular space

Question 6

Tight epithelium

Answer 6

High electrical resistance so all transport via trans cellular transport

Question 7

Proximal direction

Answer 7

Leaky epithelium
Low electrical resistance
Low number of strands
Bulk transport (para cellular)
eg proximal tubule, duodenum

Question 8

Distal

Answer 8

Tight epithelium
High electrical resistance
High number of strands
Hormonally controlled (transcellular)
eg colon

Question 9

Transport types

Answer 9

Absorption - transport from lumen to blood

Secretion - transport from blood to lumen

Question 10

Transepithelial transport rules

Answer 10

Entry exit, electrochemical gradient, electroneutrality, osmosis

Question 11

Entry exit

Answer 11

Entry for absorption is apical
Entry for secretion is basolateral membrane

Question 12

EG

Answer 12

Is entry or exit step passive or actuve

Question 13

Electroneutrality

Answer 13

Moving positive or negative ion attracts a counter ion

Question 14

Osmosis

Answer 14

Net movement of ion establishes difference in osmolarity that causes water to flow by osmosis

Question 15

What do primary active transporters do

Answer 15

Set up ion gradients

Question 16

What do entry step do

Answer 16

Often secondary active transport

Question 17

What does exit step do

Answer 17

Often passive diffusion

Question 18

Glucose-galactose malabsorption syndrome

Answer 18

Mutation to glucose symporter in small intestine - sugar is retained in intestine lumen (Inc osmolarity so water leaves u dehydrated = diarrhoea)

Question 19

Treatment for GGM

Answer 19

remove glucose and galactose from diet

Question 20

What does kidney filter

Answer 20

Amino acids, glucose, ions, water everything that spent time accumulating

Question 21

Where does glucose go if it’s not absorbed by glucose symporter

Answer 21

Urine