Biology AS - Cell Structure

Prokaryotes: Single-celled organisms – usually bacteria – and don’t have a nucleus (So DNA is not linear and is located in the cytoplasm) with Ribosomes. They are smaller and have fewer Organelles

Eukaryotes: Plant or Animal cells and have a Nucleus - have a Cellulose Cell Wall

Organelles: Parts of a cell that have a specific function

Cell Ultrastructure: The internal structure of a Cell and it's Organelles - Electron Microscopes

Mitochondria: Aerobic Respiration and ATP produced - requires energy to work

Rough Endoplasmic Reticulum: Fold and process Proteins

Nuclear Envelope: Double membrane which contains pores

Nucleus: Contains Chromatin (DNA and Proteins) and controls Cell Functions

Lysosomes: Digestive enzymes which breaks down components

Ribosomes: Where Protein and RNA are produced

Golgi Apparatus: Processes and packages Lipids, Proteins and Lysosomes

Smooth Endoplasmic Recticulum: Synthesises and processes Lipids

Vacuole: Compartment for Cell Sap

Cell Wall: Plasmodesmeta (channel for extra substances)

Centriole: Seperation of chromosomes during Cell Division (creates Spindle Fibres)

Chloroplasts: Photosynthesis with a double membrane

Cilia: Microtubules which allow Cilia to move - moves substances

Flagellum: Microtubules contract to move about and helps propel cells forward

Cytoskeleton: Protein threads inside Cytoplasm, arranged in Microfiliments and Microtubules

Vesicles: Transport substances around the cell

Magnification: How much bigger the image is than the specimen - Image Size/ Object Size = Magnification

Resolution: How well microscopes can distiguishe between two close points

- Light Microscope: Lower resolution than Electron Microscopes (0.2 micrometres and X1500 Magnification)

 -Laser Scanning Confoal Microscope: Intense light beams to scan a specimen in Fluorescent dyes - clean images and 3D

- Transmission Electron Microscope: Electron Magnets - higher resolution and shows Organelle internal structure

- Scanning Electron Microscopes: Electrons onto a Cathode Ray Tube - Surface images with lower resolution (3D)