Thursday, December 9, 2010

Cell structure

There are many different types of cells. Most of them are really small. Some you can't even see without a microscope. Well the the ones we seen we need a microscope to see them. The things that i read about are plant cells i remember talking about plants cells a long time ago, but I can't remember them all that well.
The size of a cell is small that's probably why we can't see them.
There is a cell theory and it states that 1)all organisms are composed of cells, 2) Cells are the basic units of structure and function in organisms, and 3) cells come only from preexisting cells because cells are self-reproducing. Cell are quiet small as i said before. A frogs egg is about 1 millimeter in diameter and it is large enough to be seen by an human eye. Most cells are smaller than 1mm.
I learned to different types of cells. There is the Animal cell and the plant cell.


There are many functions of each cell pictured above. 
I'll explain some few major parts of the animal cell first. 

One of the parts of the animal cell is the Peroxisome. It is the vesicle that has various functions. Its functions are it breaks down fatty acids and converts resulting hydrogen peroxide to water.

 Another one is the Mitochondrion. It is organelle that carries out cellular respiration producing ATP molecules. 

Next is the Rough ER and the Smooth ER. The Rough ER studded with ribosomes. It is also called The Endoplasmic Reticulum (ER). It is a network of membranes extented from the outer nuclear membrane used for protein synthesis and transport. It is divided into two section each with different special functions. As for the smooth ER it is The function is the sam as the Rough ER, but it lacks ribosomes synthesis and lipid molecules. 

Another one is the Nucleus. It is the central structure which contains the cell's genetic material.

The Centrosome. It is a cell structure which generally contains a pair of centrioles, used by the cell for microtubule organisation.

The Golgi Apparatus is a cell structure used to modify, store, and transport products of the ER. It is composed of a grouped series of membrane sacks.


The lysosome main function of these microscopic organelles is to serve as digestion compartments for cellular materials that have exceeded their lifetime or are otherwise no longer useful. Lysosomes break down cellular waste products, fats, carbohydrates, proteins, and other macromolecules into simple compounds, which are then transferred back into the cytoplasm as new cell-building materials.

The plasma Membrane is all living cells, prokaryotic and eukaryotic, have a plasma membrane that encloses their contents and serves as a semi-porous barrier to the outside environment. The membrane acts as a boundary, holding the cell constituents together and keeping other substances from entering. 


Now for the Plant Cell


CELL WALL
Another structure that makes this a plant cell is the cell wall. It holds the contents of the cell nicely in shape. A way to demonstrate that would be to take a piece of wood in your left hand and a piece of meat in your right hand. 

CHLOROPLAST

 It has a number of green organelles called the chloroplasts. They have a strange name, because chloros means yellow in Greek. This is where the hard work of producing sugars from carbon dioxide goes on. In the process oxygen is released. 

Thylakoid

The membrane plays an important role in separating the inside (lumen) and the outside (stroma) of the thylakoid. 

MITOCHONDRION

Another power plant in the cell is the mitochondrion. While chloroplasts run on sunlight, this organelle runs on coal well on sugars, that is. In the process of respiration, mostly occuring inside the mitochondrion, ATP is produced, which can be used to run other important processes in the cell.

Crista

This membrane contains many different proteins, most of them required for aerobic respiration.

NUCLEUS

There's generally only one nucleus per cell. It contains DNA held together by proteins.

No comments:

Post a Comment