Photosynthesis vs Respiration: Complete Comparison for NEET
Master the differences between photosynthesis and respiration with detailed comparison charts, equations, and practice questions for NEET success.
Key Takeaways
- 1Photosynthesis occurs in chloroplasts; Respiration occurs in mitochondria
- 24-6 questions appear every year from these topics combined
- 3Light reactions produce ATP, NADPH, O₂; Dark reactions (Calvin cycle) produce glucose
- 4Respiration has 3 phases: Glycolysis → Krebs Cycle → ETC (produces 38 ATP total)
- 5Remember: Photosynthesis is anabolic (builds), Respiration is catabolic (breaks down)
Remember these points for your NEET preparation
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Photosynthesis vs Respiration: Complete NEET Guide
These two fundamental processes are among the most important topics in NEET Biology, appearing in 4-6 questions every year. Understanding their differences and similarities is crucial for scoring maximum marks.
Quick Comparison Table
| Aspect | Photosynthesis | Respiration |
|---|---|---|
| Purpose | Food synthesis | Energy release |
| Location | Chloroplasts | Mitochondria |
| Raw Materials | CO₂ + H₂O | Glucose + O₂ |
| Products | Glucose + O₂ | CO₂ + H₂O + ATP |
| Energy | Light energy → Chemical | Chemical → ATP |
| Occurrence | Only in light | 24/7 process |
Detailed Process Analysis
Photosynthesis: The Food Factory
Overall Equation:
6CO₂ + 6H₂O + Light Energy → C₆H₁₂O₆ + 6O₂
Two Main Phases:
-
Light Reactions (Photo-chemical phase)
- Location: Thylakoid membranes
- Products: ATP, NADPH, O₂
- Key processes: Photolysis, electron transport
-
Dark Reactions (Bio-chemical phase)
- Location: Stroma
- Process: Calvin Cycle (C₃ cycle)
- Product: Glucose formation
Respiration: The Powerhouse
Overall Equation:
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + 38 ATP
Three Main Phases:
-
Glycolysis
- Location: Cytoplasm
- Products: 2 Pyruvate + 2 ATP + 2 NADH
-
Krebs Cycle (Citric Acid Cycle)
- Location: Mitochondrial matrix
- Products: 2 ATP + 6 NADH + 2 FADH₂
-
Electron Transport Chain (ETC)
- Location: Inner mitochondrial membrane
- Products: 34 ATP (via oxidative phosphorylation)
Key Differences for NEET
1. Metabolic Nature
- Photosynthesis: Anabolic process (builds molecules)
- Respiration: Catabolic process (breaks molecules)
2. Energy Flow
- Photosynthesis: Endergonic (requires energy input)
- Respiration: Exergonic (releases energy)
3. Gas Exchange
- Photosynthesis: Takes in CO₂, releases O₂
- Respiration: Takes in O₂, releases CO₂
4. Pigment Involvement
- Photosynthesis: Requires chlorophyll and accessory pigments
- Respiration: No pigments required
NEET Important Points
- Compensation Point: When photosynthesis rate = respiration rate
- R.Q. (Respiratory Quotient): CO₂ evolved / O₂ consumed
- Photosynthetic Quotient: O₂ evolved / CO₂ absorbed
Common NEET Questions Pattern
- Direct comparison questions (most common)
- Site/location identification
- Product/reactant identification
- Equation balancing
- Diagram-based questions
Memory Tricks
For Photosynthesis Phases: "Light reactions need Light" (Thylakoid) "Dark reactions don't need Direct light" (Stroma)
For Respiration Stages: "Glycolysis in General cytoplasm" "Krebs in Kitchen (Matrix)" "ETC on inner Envelope"
Practice Questions
- Where does the light reaction of photosynthesis take place?
- What is the net ATP gain from one glucose molecule in aerobic respiration?
- Which phase of respiration occurs in the absence of oxygen?
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