Transpiration and Photosynthesis.

Plants!

Moderators: honeev, Leonid, amiradm, BioTeam

Post Reply
harryriley88
Garter
Garter
Posts: 2
Joined: Thu Mar 13, 2014 10:10 pm

Transpiration and Photosynthesis.

Post by harryriley88 » Thu Mar 13, 2014 10:12 pm

How does Photosynthesis affect Transpiration?

Babybel56
Death Adder
Death Adder
Posts: 65
Joined: Mon Apr 18, 2011 11:35 am
Location: University of Cambridge, UK

Post by Babybel56 » Fri Mar 14, 2014 4:07 am

Photosynthesis requires water to happen. The water is photolysed (split apart) using the energy gained from sunlight, which will draw more up through the xylem from the roots. However more significantly for photosynthesis to take place there needs to be gas exchange through the stomatal pores predominantly found on the lower sides of the leaf.

If these pores are closed very little water can evapourate (transpire). So if there are low levels of photosynthesis (say, at night) then there will also be relatively low levels of transpiration. The water just cannot get out. However if the pores are left open a much greater volume of water can be lose this way.

You can therefore assume factors that increase the rate of photosynthesis (higher temperature, light intensity etc.) will also increase the rate of transpiration.

User avatar
JackBean
Inland Taipan
Inland Taipan
Posts: 5694
Joined: Mon Sep 14, 2009 7:12 pm

Post by JackBean » Fri Mar 14, 2014 10:34 am

Seriously? Do you have any idea, what is the concentration of water? Even if we assume that the cell is crowded, I'm sure the metabolism doesn't significantly influence concentration of water.

Shouldn't be the question the other way - how does transpiration affect photosynthesis?
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.

harryriley88
Garter
Garter
Posts: 2
Joined: Thu Mar 13, 2014 10:10 pm

Post by harryriley88 » Mon Mar 17, 2014 8:23 am

JackBean, if you're replying to me then it could be the other way round but in this circumstance it wasn't. It was a question on a mock exam paper which I have now found the answer to, it was basically this:
More photosynthesis
More CO2 absorbed
Which therefore increases the stomatal opening.

perfection
Garter
Garter
Posts: 1
Joined: Mon Apr 07, 2014 7:24 am

Re: Transpiration and Photosynthesis.

Post by perfection » Mon Apr 07, 2014 7:55 am

Try to consider the light and dark reaction. A plant it active during the day and photosynthsise and in the process release excess H2O contents to the atmosphere (transpiration). So the phenomenom are complimentary.

Post Reply

Who is online

Users browsing this forum: No registered users and 0 guests