Biology » Cell Biology

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.

Note paper for practical


PRACTICAL

Bacterial Growth

Watch the video and have a go at writing out the steps of the practical.

Note paper for practical