Cell Biology
Key words
Eukaryotes – organisms made up of eukaryotic cells.
Prokaryote – a prokaryotic cell.
Subcellular structures – different parts of a cell.
Animal cells – contain:
- Nucleus – contains genetic material.
- Cytoplasm – gel-like where chemical reactions happen.
- Cell membrane – holds cell together and controls what goes in and out.
- Mitochondria – where reactions for aerobic respiration take place.
- Ribosomes – where proteins are made.
Plant cells – contain the same as an animal cell plus:
- Cell wall – made of cellulose.
- Permanent vacuole – contains a weak solution of sugar and salts called cell sap.
- Chloroplasts – where photosynthesis occurs.
Bacterial cells – prokaryotic cells containing:
- Cytoplasm
- Cell membrane
- Cell wall
- Plasmids – small rings of DNA.
- Single circular strand of DNA.
Light microscopes – use light and lenses to form an image and magnify it.
Electron microscopes – use electrons to form an image and magnify it at a higher resolution.
Differentiation – a cell changes to become specialised for its job.
Chromosomes – contain genetic information.
DNA - contains deoxyribonucleic acid a chemical that all of the genetic material in a cell.
Binary Fission – when a cell splits into two.
Stem cells – undifferentiated cells that can divide to produce lots more undifferentiated cells.
Meristems – where stem cells are found in plants.
Clones – identical copies.
Diffusion – the movement of particles from an area of high concentration (lots of particles) to an area of low concentration (few particles).
Osmosis – the movement of water molecules across a partially permeable membrane from a area of high water concentration to a area of low water concentration.
Active transport – the movement of particles against a concentration gradient, from low concentration to high concentration.
Gas exchange – transfer of oxygen to the blood and removal of waste carbon dioxide which happens in the lungs.
Villi – tiny little projections found inside the small intestine.
Stomata – tiny holes on the underside of leaf (the exhange surface).
Guard cells – control the size of the stomata and the amount of water the plant loses.
Also see Photosynthesis, Reproduction, Transpiration.
PRACTICAL
Using a microscope
Watch the video and have a go at writing out the steps of the practical.
PRACTICAL
Bacterial Growth
Watch the video and have a go at writing out the steps of the practical.
