× Didn't find what you were looking for? Ask a question
Top Posters
Since Sunday
5
o
5
4
m
4
b
4
x
4
a
4
l
4
t
4
S
4
m
3
s
3
New Topic  
KaGi KaGi
wrote...
Posts: 12
Rep: 0 0
13 years ago
Explain the reabsorption of glucose and Na+ from the lumen of the nephron tubule into the
blood, using both the Na+/K+ ATPase and Na+/glucose transporter in your answer. Use a
diagram if necessary.
Read 3854 times
4 Replies

Related Topics

Replies
wrote...
13 years ago
The concentrations of Na+ and glucose in the primary urine are not different from that of the blood, so without a concentration gradient, these compounds will not move across membranes. To overcome this problem, the Na+/K+ ATPase in the basolateral membrane of the nephron pumps sodium from the cell into the peritubular space, and this creates a favorable inward Na+ electrochemical gradient on the apical side that can be used to pull Na+ into the tubule epithelial cell from the tubule lumen. This sodium movement happens through sodium channels, Na+/H+ exchangers, or other carriers. Additionally, Na+-coupled glucose uptake will also pull glucose into the epithelial cell through the action of a Na+-glucose cotransporter. Concentrating glucose within the cell causes a favorable outward chemical gradient that moves glucose out of the cell into the peritubular space (via glucose permease: facilitated diffusion). Once in the peritubular space, capillaries can recover these compounds.
B.Sc. (Biology)
wrote...
13 years ago
http://www.ppdictionary.com/tutorials/active_transport.htm
B.Sc. (Biology)
wrote...
13 years ago
thanxxxxxxxxxxxxxxxxx so much, the link is so woderful
wrote...
13 years ago
you're welcome, invite your friends  Face with Stuck-out Tongue
B.Sc. (Biology)
New Topic      
Explore
Post your homework questions and get free online help from our incredible volunteers
  813 People Browsing
 110 Signed Up Today
Related Images
  
 222
  
 247
  
 348
Your Opinion