FACTOID # 12: It's not the government they hate: Washington DC has the highest number of hate crimes per capita in the US.
 
 Home   Encyclopedia   Statistics   States A-Z   Flags   Maps   FAQ   About 
   
 
WHAT'S NEW
RELATED ARTICLES
People who viewed "Chloroplasts" also viewed:
 

SEARCH ALL

FACTS & STATISTICS    Advanced view

Search encyclopedia, statistics and forums:

 

 

(* = Graphable)

 

 


Encyclopedia > Chloroplasts

Chloroplasts are organelles found in plant cells and eukaryotic algae which conduct photosynthesis. Chloroplasts are similar to mitochondria but are found only in plants. Both organelles are surrounded by a double membrane with an intermembrane space; both have their own DNA and are involved in energy metabolism; and both have reticulations, or many foldings, filling their inner spaces. Chloroplasts convert light energy from the sun into ATP through a process called photosynthesis.


Chloroplasts are one of the forms a plastid may take, and are generally considered to have originated as endosymbiotic cyanobacteria. In green plants chloroplasts are surrounded by two lipid bilayer membranes, now thought to correspond to the outer and inner membranes of the ancestral cyanobacterium. The genome is considerably reduced compared to that of free_living cyanobacteria, but the parts that are still present show clear similarities.


The fluid within the chloroplast is called the stroma, corresponding to the cytoplasm of the bacterium, and contains tiny circular DNA and ribosomes, though most of their proteins are synthesized by the cell nucleus. Within the stroma are stacks of thylakoids, the sub-organelle where photosynthesis actually takes place. A stack of thylakoids is called a granum. A thylakoid looks like a flattened disk, and inside is an empty area called the thylakoid space or lumen. The photosynthesis reaction takes place on the surface of the thylakoid.


The photosynthetic proteins in the membrane bind chlorophyll, which is present with various accessory pigments. These give chloroplasts their green colour. Algal chloroplasts may be golden, brown, or red and show variation in the number of membranes and the presence of thylakoids.


See also

External links

  • This article contains material from the Science Primer (http://www.ncbi.nlm.nih.gov/About/Primer) published by the NCBI, which, as a US government publication, is in the public domain [1] (http://www.ncbi.nlm.nih.gov/About/disclaimer.html).
  • Chloroplast, Botany (http://reference.allrefer.com/encyclopedia/C/chloropl.html)


Organelles of the cell
Chloroplast | Mitochondrion | Centriole | Endoplasmic reticulum | Golgi apparatus | Lysosome | Myofibril | Nucleus | Peroxisome | Ribosome | Vacuole | Vesicle





  Results from FactBites:
 
Chloroplast - Wikipedia, the free encyclopedia (491 words)
Chloroplasts are organelles found in plant cells and eukaryotic algae that conduct photosynthesis.
Chloroplasts are one of the forms a plastid may take, and are generally considered to have originated as endosymbiotic cyanobacteria.
The fluid within the chloroplast is called the stroma, corresponding to the cytoplasm of the bacterium, and contains tiny circular DNA and ribosomes, though most of their proteins are encoded by genes contained in the cell nucleus, with the protein products trafficked to the chloroplast.
  More results at FactBites »

 
 

COMMENTARY     


Share your thoughts, questions and commentary here
Your name
Your comments

Want to know more?
Search encyclopedia, statistics and forums:

 


Press Releases |  Feeds | Contact
The Wikipedia article included on this page is licensed under the GFDL.
Images may be subject to relevant owners' copyright.
All other elements are (c) copyright NationMaster.com 2003-5. All Rights Reserved.
Usage implies agreement with terms, 1022, m