OCR A Level Biology A
OCR A Level Biology A Biological Molecules Exam Questions
Free OCR A Level Biology A exam questions on Biological Molecules, with mark schemes. Covers water, carbohydrates, lipids, proteins and biochemical tests.
Biological Molecules exam questions
1 question pack of real past exam questions with its mark scheme. Answer every question without notes, then mark your answers line by line against the mark scheme.
StemUp mark scheme flashcards
OCR A Level Biology A H420 Flashcards (Anki & Quizlet)
Every answer is written in mark scheme wording, so you learn exactly what examiners give marks for. Use them on Anki or Quizlet, then test yourself with the questions on this page.
From £10.99View flashcards
About OCR A Level Biology A Biological Molecules
This topic covers the molecules life is built from.
What you need to know
- Water Hydrogen bonding, solvent properties, specific heat capacity and cohesion.
- Carbohydrates Glucose isomers, glycosidic bonds, starch, glycogen and cellulose.
- Lipids Triglycerides, phospholipids and cholesterol.
- Proteins and tests Peptide bonds, protein structure, and tests including Benedict's, biuret and chromatography.
Common mistakes in Biological Molecules
- Confusing condensation and hydrolysis.
- Mixing alpha and beta glucose structures.
- Saying Benedict's detects all sugars without hydrolysis.
Try three Biological Molecules exam-style questions
1. Name the bond formed between two glucose molecules. (1 mark)
Show the mark scheme answer
Glycosidic bond.
2. Explain how cellulose structure suits its function. (2 marks)
Show the mark scheme answer
Beta glucose forms straight chains linked by hydrogen bonds (1) into microfibrils with high tensile strength (1).
3. Describe the test for a non-reducing sugar. (2 marks)
Show the mark scheme answer
Boil with dilute HCl then neutralise (1); heat with Benedict's and a brick-red precipitate forms (1).
Biological Molecules FAQs
What does Biological Molecules cover?
Water, carbohydrates, lipids, proteins and food tests.
Which practical links here?
Biochemical tests and colorimetry for glucose concentration.
Why is water a good solvent?
It is polar, so ions and polar molecules dissolve in it.
Revise this topic with flashcards: OCR A Level Biology A H420 Flashcards, with mark scheme answers for Anki and Quizlet.
