AQA A Level Chemistry复习笔记7.7.4 DNA
DNA The nucleic acid DNA is a?polynucleotide?– it is made up of?many nucleotides?bonded together in a?long chain A?nucleotide?is a building block consisting of a?phosphate group,?2-deoxyribo...
AQA A Level Chemistry复习笔记7.7.3 Enzymes
Enzymes 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 change...
AQA A Level Chemistry复习笔记7.7.2 Proteins
Enzymes 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 change...
AQA A Level Chemistry复习笔记7.7.2 Proteins
Proteins Each amino acid contains an amine (-NH2) and carboxylic acid (-COOH) group The -NH2?group of?one amino acid?can react with the -COOH group of?another amino acid?in a?condensation re...
AQA A Level Chemistry复习笔记7.6.2 Biodegradability & Disposal of Polymers
Biodegradability Biodegradable polymers Both polyesters and polyamides can be broken down using hydrolysis reactions This is a major advantage over the polymers produced using alkene monomer...
AQA A Level Chemistry复习笔记7.5.5 Quaternary Ammonium Salts
Quaternary Ammonium Salts Quaternary ammonium salts?are chemical analogues to ammonium chloride, NH4Cl, in which the hydrogens have been replaced by four alkyl groups They are very useful in...
AQA A Level Chemistry复习笔记7.5.4 Nucleophilic Addition–Elimination
Nucleophilic Addition–Elimination An important class of reactions that ammonia and amines undergo is?nucleophilic substitution?with acyl chlorides (or acid chlorides) and acid anhydrides The...
AQA A Level Chemistry复习笔记7.5.3 Nucleophilic Substitution
Nucleophilic Substitution The lone pair on the nitrogen atom in amines makes them good?nucleophiles, just like ammonia When ammonia reacts with a haloalkane a nucleophilic substitution react...
AQA A Level Chemistry复习笔记7.5.2 Basic Properties
Basic Properties The nitrogen atom in ammonia and amine molecules can?accept?a?proton?(H+?ion) They can therefore act as?bases?in aqueous solutions by?donating?its lone pair of electrons to ...
