OCR General Certificate of Secondary Education (GCSE) Biology Practice Exam

Disable ads (and more) with a membership for a one time $2.99 payment

Master GCSE Biology with our interactive exam quizzes. Utilize dynamic questions and thorough explanations to boost your understanding and excel in your GCSE Biology exam!

Each practice test/flash card set has 50 randomly selected questions from a bank of over 500. You'll get a new set of questions each time!

Practice this question and more.

What are proteins made of?

Chains of fatty acids
Chains of nucleotides
Chains of amino acids
Chains of sugars

The correct answer is: Chains of amino acids

Proteins are composed of chains of amino acids, which are organic compounds containing both an amino group and a carboxyl group. Amino acids link together through peptide bonds to form polypeptides, which then fold into specific three-dimensional structures to create functional proteins. The unique sequence of amino acids determines the protein’s structure and function, making them essential for a wide range of biological processes in living organisms, including enzyme activity, cell signaling, and structural support. The other options refer to different types of biological macromolecules: fatty acids are the building blocks of lipids, nucleotides are the units that make up nucleic acids like DNA and RNA, and sugars are the basic components of carbohydrates. Each class of biomolecule plays distinct roles in biological systems, with proteins being particularly vital due to their diverse functions.