WJEC A Level Biology
WJEC A Level Biology 1.1 Biological Compounds Exam Questions
Free WJEC A Level Biology exam questions on 1.1 Biological Compounds, with mark schemes. Covers inorganic ions, water, carbohydrates, lipids and proteins, and the tests for them.
1.1 Biological Compounds 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
WJEC A Level Biology 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.
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About WJEC A Level Biology 1.1 Biological Compounds
This topic covers the molecules that living things are made of. Expect drawing of bonds, food tests and structure-function questions.
What you need to know
- Ions and water Inorganic ions such as Mg²⁺, Fe²⁺, Ca²⁺ and PO₄³⁻ have specific roles. Water is polar, a good solvent, has high specific heat capacity and cohesion.
- Carbohydrates Monosaccharides join by glycosidic bonds in condensation. Starch, glycogen and cellulose differ in structure and function.
- Lipids Triglycerides have ester bonds; phospholipids have a hydrophilic head and hydrophobic tails.
- Proteins Amino acids join by peptide bonds. Primary to quaternary structure determines function.
Common mistakes in 1.1 Biological Compounds
- Calling hydrolysis a condensation reaction.
- Forgetting that cellulose is made of beta-glucose.
- Mixing up the Benedict's test for reducing and non-reducing sugars.
Try three 1.1 Biological Compounds exam-style questions
1. Name the bond formed between two amino acids. (1 mark)
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Peptide bond.
2. Explain how the structure of cellulose suits its function. (3 marks)
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Beta-glucose forms long straight chains (1); hydrogen bonds link parallel chains (1), forming microfibrils with high tensile strength for cell walls (1).
3. Describe the test for a non-reducing sugar. (3 marks)
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Benedict's test is negative first (1); boil with dilute acid then neutralise with alkali (1); heat with Benedict's again, brick-red precipitate if present (1).
1.1 Biological Compounds FAQs
What does Biological Compounds cover?
Inorganic ions, water, carbohydrates, lipids and proteins, and biochemical tests.
Do I need to draw structures?
Yes, including condensation and hydrolysis forming glycosidic, ester and peptide bonds.
Which practicals link to this topic?
Biochemical tests for sugars, starch, lipids and proteins.
Revise this topic with flashcards: WJEC A Level Biology Flashcards, with mark scheme answers for Anki and Quizlet.
