High school biology quiz: Test your knowledge of light-independent reactions

🧪 Quick Study Guide

• 🌍 The light-independent reactions (Calvin Cycle) occur in the stroma of the chloroplast.
• 🌱 These reactions use ATP and NADPH, produced during the light-dependent reactions, to convert carbon dioxide into glucose.
• 🔑 The cycle involves three main stages: carbon fixation, reduction, and regeneration of the RuBP acceptor.
• 🔢 Carbon fixation: $CO_2$ is attached to RuBP (ribulose-1,5-bisphosphate) by the enzyme RuBisCO.
• ⚡ Reduction: The resulting molecule is reduced using ATP and NADPH to form G3P (glyceraldehyde-3-phosphate).
• 🔄 Regeneration: RuBP is regenerated from G3P, allowing the cycle to continue.
• 💡 For every 6 molecules of $CO_2$ that enter the cycle, one molecule of glucose is produced.

Practice Quiz

1. Which of the following is the primary purpose of the light-independent reactions?
   1. Producing oxygen
   2. Converting light energy into chemical energy
   3. Fixing carbon dioxide into glucose
   4. Transporting electrons
2. Where do the light-independent reactions take place?
   1. Thylakoid membrane
   2. Stroma of the chloroplast
   3. Cristae of the mitochondria
   4. Cytoplasm
3. What is the role of RuBisCO in the Calvin Cycle?
   1. To split water molecules
   2. To fix carbon dioxide
   3. To generate ATP
   4. To transport electrons
4. Which molecule is regenerated in the Calvin Cycle to keep the cycle running?
   1. ATP
   2. NADPH
   3. RuBP
   4. G3P
5. What are the main inputs required for the light-independent reactions?
   1. $CO_2$, water, and sunlight
   2. $CO_2$, ATP, and NADPH
   3. Oxygen, ATP, and NADPH
   4. Water, ATP, and oxygen
6. What is the direct product of the Calvin Cycle that is used to make glucose?
   1. RuBP
   2. ATP
   3. NADPH
   4. G3P
7. How many molecules of $CO_2$ are required to produce one molecule of glucose?
   1. 3
   2. 6
   3. 12
   4. 1