Cell biology
Cell structure
Cells are microscopic building blocks of unicellular and multicellular living organisms. Animal, plant, fungal and bacterial cells are different in terms of structure but also have many similarities.
Transport across membranes
All cells are enclosed by a cell membrane, which is selectively permeable. Molecules can move into or out of cells by diffusion and active transport. Cells can gain or lose water by osmosis.
DNA and the production of proteins
DNA carries the genetic information in the cells of all living organisms. It contains codes for the assembly of amino acids into all the proteins required in the body.
Proteins
Proteins consist of combinations of amino acids. Body proteins include structural proteins, enzymes, hormones and antibodies. The shape of an enzyme allows it to speed up a biological reaction.
Genetic engineering
Bacteria exchange DNA using plasmids; viruses invade cells by first inserting their genetic material. Genetic engineering is the transfer of DNA between organisms using biotechnology.
Respiration
Most cell activity requires chemical energy. Respiration is the cellular process of releasing energy from food and storing it as ATP.
Video playlist
Fleming and the discovery of penicillin. Video
Sir Alexander Fleming on how he discovered the world's first antibiotic, penicillin.
DNA and proteins. Video
Synthesis of proteins, the composition of DNA and the effects they have on an organism.
Gene therapy and cystic fibrosis. Video
Explanation of the cause and effects of the genetic disorder cystic fibrosis.
Enzymes. Video
Enzymes are natural catalysts that act on specific substrates at optimum conditions.
Respiration. Video
Aerobic respiration and fermentation produce different amounts of energy.
Genetic engineering. Video
DNA transfer between bacterial cells by plasmids is the basis for genetic engineering.
Cells and their uses. Video
Substances move through cell membranes by active and passive transport.
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