Polymers and Life | OCR A-Level Chemistry B (Salters) (H433)
Polymers and Life
- 376 questions
- 21 subtopics
- The ten storylines, examined across all three papers
- Component 01, Component 02 and Component 03
The storyline that carries the nitrogen-containing groups and the biological polymers: amino acids and proteins, DNA and RNA, enzymes as catalysts, acids, amines and amides, condensation polymerisation, optical isomerism, and NMR..
It covers amino acids, the peptide link and hydrolysing a protein, chromatography of amino acids and Rf values, protein structure, dNA and RNA structure, base pairing and the genetic code, molecular recognition, enzyme kinetics, characteristics of enzyme catalysis, acidity of carboxylic acids, amino acids as zwitterions, basicity of amines, naming acids, acyl chlorides, anhydrides, esters, aldehydes and ketones, diols, dicarboxylic acids, amines, amides and the nylons, hydrolysis of esters and amides, reactions of acyl chlorides, condensation polymerisation, optical isomerism, further interpretation of mass spectra, chemical shift and equivalent protons in proton NMR, the n + 1 rule, integration and carbon-13 NMR and combined spectroscopic structure determination.
Sample questions from Polymers and Life
Answer each one closed book first, then open the answer.
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Amino acids, the peptide link and hydrolysing a protein
Which two functional groups react when a peptide link forms, and what is eliminated?
Show the answer
The COOH of one amino acid reacts with the NH₂ of another, and a molecule of water is eliminated. -
Protein structure
What happens to a protein when it is denatured?
Show the answer
The hydrogen bonds and ionic attractions holding its tertiary structure break, so the chain unfolds and loses its specific shape and function. -
Molecular recognition
Why must the bonds holding a drug to a receptor usually be weak?
Show the answer
The drug has to be released again once it has acted, which would be impossible if it were bound covalently. -
Characteristics of enzyme catalysis
Why do many medicines work as enzyme inhibitors?
Show the answer
Blocking a specific enzyme in a pathway shuts down the process that depends on it, and the specificity of the active site means other enzymes are unaffected. -
Basicity of amines
Write an equation for the reaction of ethylamine with hydrochloric acid.
Show the answer
CH₃CH₂NH₂ + HCl → CH₃CH₂NH₃⁺Cl⁻. -
Diols, dicarboxylic acids, amines, amides and the nylons
Which two monomers give nylon-6,6, and what do the two sixes refer to?
Show the answer
Hexane-1,6-diamine and hexanedioic acid; each six is the number of carbon atoms in one of the two monomers. -
Condensation polymerisation
Name the link present in a polyester and give its formula.
Show the answer
The ester link, –COO–. -
Further interpretation of mass spectra
Why can no peak in a mass spectrum lie above the M⁺ peak apart from those caused by heavier isotopes?
Show the answer
Fragmentation only removes atoms from the molecular ion, so every fragment must be lighter than the whole molecule.
The 21 subtopics
One subtopic is one session. Work down the list.
| Subtopic | What it covers | Questions |
|---|---|---|
| Amino acids, the peptide link and hydrolysing a protein | Recall questions on the general formula of an amino acid, which groups form the peptide link and what is lost, and the products of acid and alkaline hydrolysis. | 13 |
| Chromatography of amino acids and Rf values | Recall questions on the baseline and solvent front, why a locating agent is needed, ninhydrin, and calculating and using an Rf value. | 13 |
| Protein structure | Recall questions on primary, secondary and tertiary structure, the interactions between side chains, disulfide bridges, and fibrous against globular proteins. | 20 |
| DNA and RNA structure | Recall questions on the sugars, the nucleotide monomer, the phosphate backbone, and how RNA differs from DNA in structure and stability. | 22 |
| Base pairing and the genetic code | Recall questions on which bases pair and by how many hydrogen bonds, why replication is semi-conservative, and reading an amino acid sequence from codons. | 20 |
| Molecular recognition | Recall questions on why shape and functional groups decide activity, why drug-receptor bonds must be weak, and why only some related compounds work. | 19 |
| Enzyme kinetics | Recall questions on the shape of the rate-concentration curve, why it is first order then zero order, and why it levels off. | 21 |
| Characteristics of enzyme catalysis | Recall questions on specificity, the effect of temperature and pH, the optimum, and why denaturation is not reversed on cooling. | 21 |
| Acidity of carboxylic acids | Recall questions on why a carboxylic acid is acidic, its reactions with metals, carbonates and alkalis, and why a phenol gives no effervescence. | 19 |
| Amino acids as zwitterions | Recall questions on why a zwitterion forms, the isoelectric point, and why amino acids melt high and dissolve well in water. | 18 |
| Basicity of amines | Recall questions on why the nitrogen lone pair makes an amine basic, the salt formed with an acid, and the smell and solubility of short-chain amines. | 18 |
| Naming acids, acyl chlorides, anhydrides, esters, aldehydes and ketones | Recall questions on the suffix for each series, writing a structural formula from a name, and naming a compound from its structure. | 14 |
| Diols, dicarboxylic acids, amines, amides and the nylons | Recall questions on naming diols and dicarboxylic acids, the primary and secondary amide groups, and the monomers behind nylon-6,6 and nylon-6. | 12 |
| Hydrolysis of esters and amides | Recall questions on acid and alkaline hydrolysis of an ester and an amide, why the alkaline route goes to completion, and recovering the free acid. | 21 |
| Reactions of acyl chlorides | Recall questions on why an acyl chloride is so reactive, and its reactions with water, alcohols and amines and what is observed. | 18 |
| Condensation polymerisation | Recall questions on what is eliminated, which monomer pairs give a polyester and which a polyamide, and deducing a repeat unit or the monomers. | 21 |
| Optical isomerism | Recall questions on what a chiral centre is, identifying one in a structure, why the isomers are drawn in three dimensions, and racemic mixtures. | 20 |
| Further interpretation of mass spectra | Recall questions on accurate mass and why it separates compounds of the same nominal mass, and identifying fragments lost from a molecular ion. | 20 |
| Chemical shift and equivalent protons in proton NMR | Recall questions on the TMS reference, what chemical shift depends on, equivalent protons, and the shift ranges for the common environments. | 14 |
| The n + 1 rule, integration and carbon-13 NMR | Recall questions on the splitting patterns and what they show, what the integration trace gives, and how a carbon-13 spectrum is read. | 12 |
| Combined spectroscopic structure determination | Recall questions on combining infrared, mass spectrometry and NMR, and on working a structure out from a set of spectra. | 20 |
How the guide is worked
Answering a question from memory stores it far better than reading the answer again. The guide runs that as a fixed procedure on one subtopic at a time, about twenty minutes a session.
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Step 1 · Closed book
Cover the answers. Work through one subtopic and write down what you can. Leave blanks where you have nothing.
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Step 2 · Open book
Go back to the top. Read each printed answer and write it out in full, including the ones you had right.
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Step 3 · Closed book again
Same questions, same order, from memory. The gap between pass one and pass three is the session result.
Read the full method, the return schedule and the research behind it.
Nearby topics
OCR A-Level Chemistry B (Salters) Active Recall Guide
Every topic, not just this one. 3,430 questions with their answers.