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

What role do amino acids play in protein synthesis?

1. They are catalysts for reactions

2. They are the building blocks of proteins

3. They store genetic information

4. They transport nutrients across cell membranes

The correct answer is: They are the building blocks of proteins

Amino acids play a crucial role in protein synthesis as they are the fundamental building blocks of proteins. During the process of protein synthesis, amino acids are linked together in a specific sequence determined by the genetic code, which is transcribed from DNA to messenger RNA. This sequence ultimately dictates the protein's structure and function. Each protein is composed of one or more chains of amino acids, and the order of these amino acids is what gives each protein its unique characteristics and roles within biological processes. The other options do not accurately describe the role of amino acids in protein synthesis. Catalysts for reactions refer to enzymes, which are themselves proteins but not amino acids. Storing genetic information pertains to nucleic acids, such as DNA and RNA, rather than amino acids. Transporting nutrients across cell membranes is a function of specific proteins, not the amino acids themselves. Thus, the correct understanding highlights that amino acids are essential for constructing proteins, making "they are the building blocks of proteins" the accurate choice.