Login

Join for Free!
116866 members


Sun and shade chloroplast

Plants!

Moderator: BioTeam

Sun and shade chloroplast

Postby Charlie » Wed Oct 04, 2006 7:10 pm

Can anyone tell me the main differences between sun and shade chloroplasts?
Thanks
Charlie
Garter
Garter
 
Posts: 17
Joined: Sun Oct 30, 2005 3:06 pm

sun vs shade leaves?

Postby honee_v » Tue Oct 10, 2006 2:25 pm

could it be u r asking bout the difference between sun and shade leaves? sun and shade leaves differ in many ways.. primarily sun leaves are exposed to direct sunlight; shade leaves arent as they are shaded by others... morphologically they differ in a way that sun leaves tend to be smaller (than shade leaves), with shorter internodes (refers to that portion of the stem between one node to another) and thicker cuticle (i.e. the waxy layer on the outer surface of the leaf) .. all of which to prevent excessive loss of water during transpiration (basically a process of water evaporation via leaf pores)


^_^
"Why you care about small things? World very simple place...
World only have two things: Things you can eat and things you no can eat."

- Quina Quen (ffix)
User avatar
honee_v
Site Admin
Site Admin
 
Posts: 322
Joined: Thu Jun 22, 2006 9:28 am

Postby honee_v » Tue Oct 10, 2006 2:59 pm

then in terms of chloroplast distribution, chloroplasts in sun leaves concentrate on the palisade layer while chloroplasts in shade leaves are evenly distributed between the palisade and spongy mesophyll layers..

Chloroplasts in sun leaves tend to move away after taking their turns in the bright light. they find shade from others where they could use the light they absorbed. this is to prevent being exposed too long to sunlight which we know cud be damaging to them. Perhaps it is tis reason y sun leaves tend to develop longer/additional layer of palisade cells...

anyways in shade leaves, chloroplasts can also move about but in a place inside the cell where they can absorb maximum light without shading other chloroplasts below them...

^_^
"Why you care about small things? World very simple place...
World only have two things: Things you can eat and things you no can eat."

- Quina Quen (ffix)
User avatar
honee_v
Site Admin
Site Admin
 
Posts: 322
Joined: Thu Jun 22, 2006 9:28 am


Postby MrMistery » Tue Oct 10, 2006 6:17 pm

oh i do remember something the physiology professor was saying last year, but my memory is sooo bad. in shade, the synthesys of chlorophil cannot take place and the thylakoid membranes do not form. some sort of tubules form instead that can be converted to normal thylakoid membranes if the chloroplast is exposed to light.. I hate my memory
"As a biologist, I firmly believe that when you're dead, you're dead. Except for what you live behind in history. That's the only afterlife" - J. Craig Venter
User avatar
MrMistery
Inland Taipan
Inland Taipan
 
Posts: 6832
Joined: Thu Mar 03, 2005 10:18 pm
Location: Romania(small and unimportant country)

Postby SU_reptile » Thu Oct 19, 2006 8:11 pm

in shade, the synthesys of chlorophil cannot take place and the thylakoid membranes do not form. some sort of tubules form instead that can be converted to normal thylakoid membranes if the chloroplast is exposed to light


As far as I know "shade chloroplasts" are etioplasts. That structure that may be converted into normal tylakoid is called prolamellar body :) .
Membranes of the tubular lattice of prolamelar body contain enzyme called NADPH-protochlorophyllide oxydoreductase that catalyses transformation protochlorophyllide to chlorophyllide, which is direct precursor of chlorophyll.
Etioplasts arise from proplastids if plant is etiolated (not being exposed to light before plastid differentiation). Further exposure to light triggers a set of reactions (with NADPH-protochlorophyllide oxydoreductase for example) that lead to developing normal chloroplast.

If it's not enough for you, I will try to read more about this in my books or try to find some websites explaining that issue more clearly :wink: .
SU_reptile
Coral
Coral
 
Posts: 145
Joined: Mon May 01, 2006 6:38 pm
Location: Katowice - Poland

Postby MrMistery » Fri Oct 20, 2006 6:12 pm

thanks for the extra info SU_reptile. I did know they were called etioplasts, but couldn't remember exactly the details. Thanks again...
"As a biologist, I firmly believe that when you're dead, you're dead. Except for what you live behind in history. That's the only afterlife" - J. Craig Venter
User avatar
MrMistery
Inland Taipan
Inland Taipan
 
Posts: 6832
Joined: Thu Mar 03, 2005 10:18 pm
Location: Romania(small and unimportant country)

Postby SU_reptile » Sat Oct 21, 2006 7:14 pm

thanks for the extra info SU_reptile. I did know they were called etioplasts


I also remembered the name and prolamelar body but I am not able to remember all that complex substances and reactions, so you're not alone :wink: . Thx anyway.

I only hope that that description was helpfull for Charlie.
SU_reptile
Coral
Coral
 
Posts: 145
Joined: Mon May 01, 2006 6:38 pm
Location: Katowice - Poland


Return to Botany Discussion

Who is online

Users browsing this forum: No registered users and 0 guests

cron