Enzymes as Catalysts Enzymes are biological catalysts ‘Biological’ because they function in living systems ‘Catalysts’ because they speed up the rate of chemical reactions without being used up or ...
Translation Translation occurs in the cytoplasm of the cell After leaving the nucleus via a nuclear pore, the mRNA molecule attaches to a ribosome In the cytoplasm, there are free molecules of tRNA...
Transcription A gene is a sequence of nucleotide bases in a DNA molecule that codes for the production of a specific sequence of amino acids, that in turn make up a specific polypeptide (protein) T...
Nature of the Genetic Code A gene is a sequence of nucleotides that forms part of a DNA molecule (one DNA molecule contains many genes) This sequence of nucleotides (the gene) codes for the product...
Semi-conservative Replication of DNA Before a (parent) cell divides, it needs to copy the DNA contained within it Doubling the DNA ensures that the two new (daughter) cells produced will both recei...
DNA Purification Practical investigations can be conducted to purify (isolate) DNA via the process of precipitation Isolating DNA from cells is an essential starting point for a huge range of other...
DNA Structure The nucleic acid DNA is a polynucleotide – it is made up of many nucleotides bonded together in a long chain A DNA nucleotide DNA molecules are made up of two polynucleotide st...
Structure of ATP & ADP All organisms require a constant supply of energy to maintain their cells and stay alive In all organisms this energy is required for: Anabolic reactions (building larger...
Nucleotides DNA and RNA are nucleic acids: polymers that are made up of many repeating units (monomers) called nucleotides Each nucleotide is formed from: A pentose sugar (a sugar with 5 carbon ato...
