measurement of photosynthesis rate +-red filter in elodea

Plants!

Moderators: honeev, Leonid, amiradm, BioTeam

Post Reply
acherentia
Garter
Garter
Posts: 1
Joined: Fri Mar 19, 2010 12:19 am

measurement of photosynthesis rate +-red filter in elodea

Post by acherentia » Fri Mar 19, 2010 12:39 am

Hi,

I did a lab today in which I measured the oxygen evolution rate in Elodea in the presence/absence of a red filter.

I would like to know if a lower oxygen evolution in the presence of a red filter as shown by my experiments is the correct way to go for the lab report.

The lab manual also does not specify what a red filter does(it's basically a red plastic). I am assuming that it blocks absorption of all red wavelengths and therefore reduces photosynthetic rate. Can someone please confirm my assumption? I don't even know if Elodea absorbs in the red spectrum but the articles I see online seem to confirm that it does.

We used water with sodium bicarbonate. I am curious what the sodium bicarbonate does to the plants and why it is put in the test tubes. I didn't find a reason for that in my lab manual.

Thank you.

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

Post by JackBean » Fri Mar 19, 2010 6:53 am

As you can see here, the chlorophylls have two absorpsion maxima, in the red and blue parts, so if the light has to go through red filter, basically the red light is not available.

The Elodea is whole in water, right? You need some CO2 for the photosynthesis, that's way you have sodium bicarbonate in water ;)
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.

User avatar
robsabba
Coral
Coral
Posts: 106
Joined: Tue Aug 25, 2009 6:53 pm
Location: North Dakota State University

Re: measurement of photosynthesis rate +-red filter in elodea

Post by robsabba » Mon Apr 05, 2010 4:32 pm

acherentia wrote:Hi,

I did a lab today in which I measured the oxygen evolution rate in Elodea in the presence/absence of a red filter.

I would like to know if a lower oxygen evolution in the presence of a red filter as shown by my experiments is the correct way to go for the lab report.

The lab manual also does not specify what a red filter does(it's basically a red plastic). I am assuming that it blocks absorption of all red wavelengths and therefore reduces photosynthetic rate. Can someone please confirm my assumption? I don't even know if Elodea absorbs in the red spectrum but the articles I see online seem to confirm that it does.

We used water with sodium bicarbonate. I am curious what the sodium bicarbonate does to the plants and why it is put in the test tubes. I didn't find a reason for that in my lab manual.

Thank you.

A red filter will allow red light through, which is why we perceive it as red. It would block other wavelengths, such as blue. Photosyntheis has maxima in the blue and red ranges.

chris123
Garter
Garter
Posts: 1
Joined: Mon Jul 05, 2010 5:14 am

Post by chris123 » Wed Nov 17, 2010 5:32 am

i am chris and i am a big fan of this site. i like this type information and i have ever never seen such type of data at other pklaces like it. i would like to especially appreciate you all peopl on this attempt.
chris

Post Reply

Who is online

Users browsing this forum: No registered users and 2 guests