IGCSE Biology Most important Questions for 2026 exams (1.Enzymes)

This is a short segment from the IGCSE Biology Course for 2026

Join my IGCSE Live Biology classes every week on Zoom 👇
https://chem-bio.info/igcse-june-2026...

Get the full course of IGCSE Biology and study by your own pace 👇
https://www.chem-bio.info/igcse-biolo...

Get the latest 2026 notes for IGCSE Biology 🧪
https://www.chem-bio.info/ebooks-library
Enzymes for IGCSE biology
• Substrate fits into the active site of the enzyme 🔑
▪ A successful collision occurs when the substrate fits into the active site.
▪ Enzymes are proteins; their shape is determined by the order of amino acids. 🔬
▪ The shape of the active site is complementary to the substrate. 🧩
• Enzyme and substrate bind temporarily to form a complex 🔗
• They bind temporarily like a lock and key. 🔒
• This combination is known as the enzyme-substrate complex.
• Explains enzyme specificity (each enzyme fits only one substrate). 🎯
• Product is formed ⚙️
• The enzyme-substrate complex is short-lived.
• The enzyme breaks the substrate into products. 🔄
• The product no longer fits in the active site and is expelled. 🚀
• Enzyme is available to catalyze a new reaction ♻️
• The active site is empty.
• Enzyme structure remains unchanged. 🔄
• The enzyme can catalyze a new reaction.
• Enzymes are renewable and can be reused. 🔁
#igcsebiology #pastpapers #paper6 #paper4 #igcse #enzymes