OCR A Level Biology:复习笔记2.3.6 The Genetic Code
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...
OCR A Level Biology:复习笔记2.3.5 DNA Replication
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...
OCR A Level Biology:复习笔记2.3.4 DNA Purification
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...
OCR A Level Biology:复习笔记2.3.3 DNA: Structure
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...
OCR A Level Biology:复习笔记2.3.2 Phosphorylated Nucleotides
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...
OCR A Level Biology:复习笔记2.3.1 Nucleotides & Phosphodiester Bonds
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...
OCR A Level Biology:复习笔记2.2.17 Chromatography
Chromatography Chromatography is a technique that can be used to separate a mixture into its individual components Chromatography relies on differences in the solubility of the different chemicals ...
OCR A Level Biology:复习笔记2.2.16 Finding the Concentration of a Substance
Finding the Concentration of a Substance Benedict’s solution can be used to carry out a semi-quantitative test on a reducing sugar solution to determine the concentration of reducing sugar present ...
OCR A Level Biology:复习笔记2.2.15 Biochemical Tests: Proteins
Biochemical Tests: Proteins The Biuret test can be carried out quickly and easily in a lab to determine if a sample contains proteins Biuret ‘reagent’ contains an alkali and copper (II) sulfate whi...
