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

How is glucose utilized in the production of proteins?

1. It directly forms proteins in the leaf cells

2. It combines with fat to create amino acids

3. It combines with nitrates from the soil to create amino acids

4. It acts as a catalyst for protein synthesis

The correct answer is: It combines with nitrates from the soil to create amino acids

Glucose plays a crucial role in the production of proteins, particularly in the synthesis of amino acids, which are the building blocks of proteins. In plants, glucose produced during photosynthesis is used in various metabolic pathways. One of these pathways involves the combination of glucose with nitrates absorbed from the soil. Nitrates are a significant source of nitrogen, which is essential for the production of amino acids. The process begins when glucose undergoes conversion in the plant cell to create energy and is then involved in synthesizing organic compounds like amino acids when combined with nitrogen from nitrates. This is particularly important because amino acids are necessary for the construction of proteins, which perform a wide range of functions in the body. The other choices miss the mark because proteins are not directly formed from glucose; they require amino acids as precursors. Additionally, while fats can provide energy and function in biological processes, they do not combine with glucose to form amino acids. Lastly, glucose does not act as a catalyst in protein synthesis; rather, it provides the necessary components and energy required during the synthesis process.