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

Maintaining stable body conditions, often referred to as homeostasis, is crucial because it ensures that the body's internal environment remains relatively constant, even when external conditions change. This stability is vital for metabolic reactions to function optimally. Enzymes, which are responsible for speeding up metabolic processes, have specific temperature and pH ranges in which they operate effectively. If these conditions fluctuate significantly, enzyme activity can be inhibited, leading to reduced metabolic efficiency or even failure. Therefore, by keeping body conditions stable, metabolic reactions can occur at the right speed and in the right amounts, allowing the organism to function properly and remain healthy.