F211 OCR Biology 1 (Chapter 1)

• Early microscopes (light microscopes) use glass lenses to refract light rays and produce a mangnified image of an object
• Light is focused on a specimen using a condenser lens
• The light passes through the specimen and and is refracted by the objective lens (x100)
• The eyepeice lens (x10) creates the last image

(ultrastructure of an animal cell)

(ultrastructure of a plant cell)

Nucleus; made up of the nuclear envelope, nuclear pores, chromatin, nucleolus and chromosomes - contains all the genetic material, holds instructions for making protiens, where transcriptions takes place, information is copied onto RNA molecule, which travels out of the nucleus through the nuclear pores in the nuclear envelope. 
Nucleolus; the especially darkly stained area in the nucleus - contains DNA to make ribosomes, tiny organelles where protien synthesis takes place
Nuclear Envelope; the nucleus is surrounded by two membranes with small a gap between them, it also contains nuclear pores - it allows material in and out of the nucleus through the pores 
Endoplasmic Reticulum;  a series of membrane bound sacs with space between the membranes called the cisterna, where protein molecules are stored, some have ribsomes attatched and form RER others do not and are known as SER - RER, proteins are made in the ribosomes and stored in the cisterna before being transported. SER has various functions, one of which is hormones 
Golgi Apparatus; not a stable structure, form a stack of curved flatterned bound sacs  - proteins move from the RER in vesticles, that bind to the Golgi and form a new layer, where they are modified and 
Ribosomes;  small organelles made up of RNA's and protein subunits - where protien synthesis takes place 
Mitochondria; surrounded by a nuclear envelope, the inner membrane froms a cristae, the background material is known as the matrix - where areobic respiration takes place, oxygen produced from glucose is used to produce ATP 

Lysosomes; tiny bags of digestive enzymes surrounded by a single membrane 0.5 µm in size - they fuse with vesticles containing containing substances to be digested, the enzymes break down molecues into soluable substances
Cilla and Flagella; long thin extensions from the surface of the cell, they contain microtubles to enable them to move - by rubbing together the microtubles allow movement to occur
Centrioles; - a centriole is made up of a set of specificically arranged microtubles - they form spindles, and are responsible for moving chromosomes in and out of the cells
Plasma Membrane; - a thin layer of lipids and protein molecules - partially permeable, controls what leaves and enters the cell
Chloroplasts; they are surrounded by a nuclear envelope and contain membranes called grana which from stacks called thylakoids - light dependant reactions take place in the grana, light energy in chlorophyll is used to split water molecules to produce H ions which are used to produce ATP
Vacuole; a membrane bound organelle that contains liquid, the membrane is known as the tonoplast 
Cytoskeleton; A network of protein filaments called microfilaments suport the cell and determine its shape and microtubules, provided mechanical strength and the microtubles act as motors using ATP helping the cell to move

(the function of a golgi apparaus)

(the structure of a typical prokaryotic cell)

(comparison of the ultrastructure of eukaryotic and prokaryotic cells)