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

What additional functions do chloroplasts serve apart from photosynthesis?

1. Production of chlorophyll only

2. Storage of nutrients

3. None; they only carry out photosynthesis

4. Formation of amino acids

The correct answer is: None; they only carry out photosynthesis

Chloroplasts are primarily known for their role in photosynthesis, where they convert sunlight into energy, producing glucose and oxygen from carbon dioxide and water. However, they also perform several other essential functions beyond just photosynthesis. One notable function is the synthesis of certain biomolecules. For instance, chloroplasts can synthesize amino acids, which are fundamental building blocks of proteins. This capability is important for plant growth and development, as proteins play crucial roles in various biological processes within the plant. Chloroplasts are also involved in the production of certain lipids and fatty acids, contributing to the plant's energy storage and cellular structure. Additionally, they can store specific starches and other carbohydrates formed during photosynthesis for later use when sunlight is not available. While the production of chlorophyll is critical for capturing light energy, it is simply one aspect of the broader range of functions that chloroplasts fulfill. Hence, stating that chloroplasts only carry out photosynthesis overlooks their varied roles in the overall metabolism and nutritional support of the plant.