Magnification – the degree to which the size of an image is larger than the object itself.
Resolution - the degree to which it is possible to distinguish between two objects that are close together. The higher the resolution, the greater the detail that can be seen.
- x1500 magnification
- 200nm resolution
- x100 000 magnification
- 0.1nm resolution
- x500 000 magnification
- 0.1nm resolution
Staining- stains bind to specific structures increasing contrast and making different structures more visible.
Magnification = Image Size / Actual Size
Nucleus - controls activity of the cell.
Nucleolus – RNA synthesis.
Nuclear Envelope – controls movement of mRNA out of the nucleus.
Rough ER – transports proteins.
Smooth ER – makes and transports lipids.
Golgi Apparatus – modifies and packages proteins.
Ribosomes – protein synthesis.
Mitochondria – aerobic respiration.
Lysosomes – contain powerful digestive enzymes.
Chloroplasts – photosynthesis.
Plasma Membrane – controls entry and exit of molecules from the cell.
Centrioles – form the spindle (only in animal cells and some protoctists).
Flagella – spin using ATP to allow movement of bacterial cells.
Cilia – waft rhythmically, e.g. to move mucus form the lungs.
Nucleus – hold the DNA for the protein.
Nucleolus – make an mRNA copy of the gene
Nuclear Envelope – mRNA moves out of the nucleus through one of the pores.
Rough ER – mRNA attaches to a ribosome on the rough ER.
Ribosomes – 'read' the code on the gene and uses the code to make the protein.
Golgi Apparatus – processes and packages protein into vesicles, these pinch off and move through the cytoplasm.
Cell Membrane – vesicle moves along the cytoskeleton and attaches to the cell membrane, releasing the protein outside the cell.
Actin Filaments – able to move against each other.
Microtubules – made from the protein tubulin.
used to move a micro-organism through a liquid or to waft a liquid past a cell.
Microtubule Motors – move organelles and other cell content along the fibres. e.g. vesicles.
- use ATP to drive the movement.
- Plasma membrane
- DNA wrapped around Histone Proteins
- Larger Ribosomes
- No plasma membrane
- Naked DNA
- Smaller Ribosomes
- Cell Membrane
- Cell membrane and cell wall
Within Cells – control exchange of materials between organelles and cytoplasm.
provide separate areas for reactions (aerobic respiration in mitochondria).
isolate enzyme (lysosomes).
provide an internal transport system.
provide surfaces for reactions (chloroplasts & mitochondria).
Outside Cells – partially permeable barrier.
controls exchange of materials between the cell and its environment.
communicate by cell signalling.
receptor bind to specific hormones.
Phospholipids – forms the basic structure, acting as a barrier to lipid and protein molecules.
Cholesterol – gives the membrane mechanical stability.
Glycolipids – cell recognition and cell adhesion.
Proteins – act as receptors for cell signalling; transport specific molecules.