What is chloroplast?

Answer 1

Chloroplasts are organelles found in plant cells and eukaryotic algae that conduct photosynthesis. Chloroplasts absorb sunlight and use it in conjunction with water and carbon dioxide to produce sugars. Chloroplasts capture light energy from the sun to conserve free energy in the form of ATP and reduce NADP to NADPH through a complex set of processes called photosynthesis. It is derived from the Greek words chloros which means green and plast which means form or entity.

Chloroplasts are observable morphologically as flat discs usually 2 to 10 micrometer in diameter and 1 micrometer thick. The chloroplast has a two-membrane envelope termed the Inner & Outer membrane respectively. Between these two layers is the intermembrane space.

The material within the chloroplast is called the stroma, corresponding evolutionary to the cytosol of the bacterium, and contains one or more molecules of small circular DNA. It also contains ribosomes, although most of its proteins are encoded by genes contained in the cell nucleus, with the protein products transported to the chloroplast.

Within the stroma are stacks of thylakoids, the sub-organelles where photosynthesis actually takes place. A stack of thylakoids is called a granum (plural: grana). 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 membrane of the thylakoid, and, as is also the case with mitochondria, involves the coupling of cross-membrane fluxes with biosynthesis via the dissipation of a proton electrochemical gradient.

Embedded in the thylakoid membrane is a dish of chlorophyll molecules known as the antenna complex. This outer array helps to increase the surface area of light capture. The photons are then funneled to the centre of this complex. Two chlorophyll molecules are then ionised, producing an excited electron which then passes onto the photochemical reaction centre.

click to learn more and for diagrams --

1) http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/C/Chloroplasts.html

2) http://images.google.co.in/images?hl=en&q=chloroplast&btnG=Search+Images&gbv=2

Answer 2

Certainly a chloroplast is indeed what your first respondent told you, but chloroplasts are really neat little structures... they do what no other structure can do -- they change sunlight into energy that a plant can use to build tissues, leaves, bark and fruit... and only plants can do that. Wouldn't it be cool if we never had to eat --- just drink water, and chloroplasts could build our tissues, help us grow, give us energy????... We could have them covering our body, just like in plants. A really totally cool plant to see chloroplasts in is call Elodea. Google it. Has to be a photo of one somewhere. Elodea is an alga of some sort, (again, you'd have to google it....) and when you put it under a microscope in a wet mount, the light will shine right thru the cell, but these little green guys within the cell race around the outside of the cell.... those little green guys are chloroplasts... totally wonderful..

Answer 3

What Is Chloroplast

Answer 4

Chloroplasts are organelles within any plant cell or protist (such as algae). They take in solar energy and turn it into food for the cell/plant to use as energy. Thus photosynthesis takes place.

Answer 5

What is chloroplast in cells

Answer 6

A plastid in the cells of green plants and green algae that contains chlorophylls and carotenoid pigments and creates glucose through photosynthesis.

Answer 7

The cell organelle having chlorophyll.

Answer 8

this is so SMART bullshit

Answer 9

idk what is it?
im trying ot find the same thing.