Biology AS (1)

Plasma Membrane 
- Found on the surface of animal cells and inside the cell wall of plant cells and prokaryotic cells.
-Made up of proteins and lipids.
-Regulates the movement of substances in and out the cell.
-Covered in receptor molecules wgich allow it to respind to hormones etc.

Cell Wall
-Rigid structure that surrounds plant cells.
-Made up of carbohydrate cellulose.
-Supports plant cells. 

Nucleus
-surrounded in a double membrane, which contains many pores for movement.
-contains chromatin, made from proteins and D.N.A that control the cell's activities.
-contains a nucleolus to make ribosomes 

Lysosome
-round organelle surrounded by a membrane
-contains digestive enzymes to digest invading cells or break down worn out components of the cell.

Ribosome
-Either floats free or is attatched to the R.E.R
-the site where proteins are made.

Rough Endoplasmic Reticulum
-membrane system enclosing a fluid-filled space
-surface covered in Ribosomes
-folds and processes proteins that have been made at the Ribosomes. 

Smooth Endoplasmic Reticulum
-no Ribosomes
-Synthesises and processes lipids.  

Vesicle
- small fluid filled sac in the cytoplasm
-made at the Golgi Apparatus, Endoplasmic Reticulum or the cell surface.
-transports substances in and out of the cell and between organelles.

Golgi Apparatus

-group of fluid filled flattened sacs
-processes and packages new lipids and proteins
-makes lisosomes

Mitochondria
-double membrane
-inner membrane folded to form Crustae.
-inside is the matrix conatining enzymes involved in respiration
-the site of aerobic resperation, where A.T.P is produced. 

 Chloroplast
-double membrane 
- inner membranes called Thylakiod membranes stacked to form Grana and linked by Lamallae
-the site of photosynthesis, some occurs in the Grana, other in the stroma (found in chloroplasts).

Centriole
-hollow cylinders
-contain a ring of microtubules
-involved in the seperation of chromosones during cell division

Cilia
-small hair like structures found on the surface of some animal cells
-conatin a ring of nine pairs of microtubules and an inner pair
-microtubules allow movement
-movement moves substances along the cell surface  

Flangellum
-longer than cilia
-9 pairs of microtubules and one pair in the centre
-microtubules contract for movement
-propel cells forward