Class 11 Biology Chapter 14 : RESPIRATION IN PLANTS NCERT Complete short Notes | NEET 2027

Hello NEET Aspirants! 👋

NEET Dropper here dropping Ch-14: Respiration in Plants

Complete Notes + PYQ Tod + No Ratta Only Samajh 🧠

Glycolysis = 2 ATP + 2 NADH = Cytoplasm

Krebs = 2 ATP + 6 NADH + 2 FADH2 = Matrix  

ETS = 32 ATP = Inner Membrane = O2 → H2O

### *1. RESPIRATION KYA HAI* `Basic Line`

Definition = Catabolic + Exergonic + Oxidation Process

Equation: C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy = 38 ATP in Theory, 30-32 ATP Actual

Site = All Living Cells = Cytosol + Mitochondria

Diff from Photosynthesis = Oxidation vs Reduction, Energy Release vs Store

Diff from Breathing = Biochemical vs Physical, Cell Level vs Organ Level

*Figure 1: Respiration vs Photosynthesis*

                    Photosynthesis                Respiration

Site                Chloroplast                   Cytosol + Mitochondria  

Raw Material        CO2 + H2O                     Glucose + O2

Product             Glucose + O2                  CO2 + H2O

Energy              Store = ATP Synthesis         Release = ATP Breakdown

Light               Needed                        Not Needed

Anabolic/Catabolic  Anabolic                      Catabolic

---

### *2. GLYCOLYSIS = EMP Pathway* `Cytoplasm = No O2 Needed`

*A. Steps = 10 Steps = 2 Phases*

Phase 1: Preparatory = Glucose 6C → 2 × G3P 3C = 2 ATP Used

Phase 2: Pay-off = 2 × G3P → 2 × Pyruvate 3C = 4 ATP + 2 NADH Made

Net Gain = 4 ATP - 2 ATP = 2 ATP + 2 NADH = 8 ATP if NADH → Mitochondria

*Figure 2: Glycolysis Flow Chart*

Glucose 6C

   ↓ Hexokinase + ATP

Glucose-6-P

   ↓ Isomerase  

Fructose-6-P

   ↓ PFK + ATP = Key Step = Allosteric = Rate Limiting

Fructose-1,6-BP

   ↓ Aldolase

DHAP 3C ←→ G3P 3C  = Triose Phosphate

   ↓ 2× G3P

   ↓ + 2NAD+ → 2NADH + 2H+

2 × 1,3-BPG

   ↓ 2 ADP → 2 ATP = Substrate Level Phosphorylation

2 × 3PGA

   ↓

2 × 2PGA

   ↓

2 × PEP

   ↓ 2 ADP → 2 ATP = Substrate Level Phosphorylation

2 × Pyruvate 3C = End Product

*Key Enzymes NEET*

Hexokinase = Glucose → G6P = ATP Used

PFK = Phosphofructokinase = F6P → F1,6BP = ATP Used = Committed Step

Pyruvate Kinase = PEP → Pyruvate = ATP Made

### *3. FATE OF PYRUVATE* `3 Raste`

**Condition** **Process** **Location** **End Product** **ATP**

**Aerobic** Krebs Cycle + ETS Mitochondria CO2 + H2O 36 ATP

**Anaerobic** Fermentation Cytoplasm Ethanol + CO2 or Lactic Acid 2 ATP

**O2 Deficient** Anaerobic Respiration Cytoplasm Ethanol = Yeast, Lactate = Muscle 2 ATP

*Figure 3: Pyruvate Fate*

                Pyruvate 3C

                /    |    \

              /      |      \

          O2      No O2    O2 Deficient

          ↓         ↓         ↓

      Mitochondria  Yeast   Muscle/Plant

          ↓         ↓         ↓

     Acetyl CoA  Acetaldehyde  Lactate

          ↓         ↓         ↓

     Krebs Cycle  Ethanol + CO2  Lactic Acid

          ↓         ↓         ↓

      36 ATP      2 ATP      2 ATP

### *4. AEROBIC RESPIRATION*

*A. Link Reaction = Pyruvate → Acetyl CoA* `Mitochondrial Matrix`

Pyruvate 3C + CoA + NAD+ → Pyruvate Dehydrogenase → Acetyl CoA 2C + CO2 + NADH

Complex Enzyme = Mg2+ + TPP + Lipoic Acid + FAD + NAD+

For 1 Glucose = 2 Pyruvate → 2 Acetyl CoA + 2 CO2 + 2 NADH = 6 ATP

*B. Krebs Cycle = TCA = Citric Acid Cycle* `Matrix = Sir Hans Krebs 1937`

*Figure 4: Krebs Cycle*

Oxaloacetate 4C

   ↓ + Acetyl CoA 2C = Citrate Synthase

Citrate 6C

   ↓ Aconitase

Isocitrate 6C

   ↓ + NAD+ → NADH + CO2 = Isocitrate Dehydrogenase = Rate Limiting

α-Ketoglutarate 5C

   ↓ + NAD+ + CoA → NADH + CO2 = α-KGDH Complex

Succinyl CoA 4C

   ↓ + GDP → GTP → ATP = Substrate Level Phosphorylation = Succinyl CoA Synthetase

Succinate 4C

   ↓ + FAD → FADH2 = Succinate Dehydrogenase = Inner Membrane

Fumarate 4C

   ↓ Fumarase + H2O

Malate 4C

   ↓ + NAD+ → NADH = Malate Dehydrogenase

Oxaloacetate 4C = Regenerated

*Net from 1 Acetyl CoA*

3 NADH = 9 ATP, 1 FADH2 = 2 ATP, 1 GTP = 1 ATP = Total 12 ATP

For 1 Glucose = 2 Acetyl CoA = 24 ATP

*C. ETS = Electron Transport System* `Inner Mitochondrial Membrane`

*Figure 5: ETS + Oxidative Phosphorylation*

Complex I  = NADH Dehydrogenase = NADH → FMN → Fe-S → UQ = 4H+ Pump

Complex II = Succinate Dehydrogenase = FADH2 → Fe-S → UQ = No H+ Pump

Complex III= Cyt bc1 = UQ → Cyt b → Fe-S → Cyt c1 → Cyt c = 4H+ Pump

Complex IV = Cyt c Oxidase = Cyt c → Cu → Cyt a → Cyt a3 → O2 = 2H+ Pump = O2 + 4H+ + 4e- → 2H2O

Complex V  = ATP Synthase = F0-F1 = H+ Flow → ATP = Chemiosmosis = Peter Mitchell

*ATP Count*

NADH = 3 ATP = Pass 3 Complex I, III, IV

FADH2 = 2 ATP = Pass 2 Complex III, IV

O2 = Terminal Acceptor = H2O Formation

### *5. AEROBIC RESPIRATION ATP CHART* `NEET King Table`

**Stage** **ATP Direct** **NADH** **FADH2** **Total ATP**

**Glycolysis** 2 ATP 2 NADH = 6 ATP 0 8 ATP

**Link Reaction** 0 2 NADH = 6 ATP 0 6 ATP

**Krebs Cycle** 2 GTP = 2 ATP 6 NADH = 18 ATP 2 FADH2 = 4 ATP 24 ATP

**Total** **4 ATP** **10 NADH = 30 ATP** **2 FADH2 = 4 ATP** **38 ATP Theory**

*Actual = 30-32 ATP*

Reason = NADH Shuttle Cost = 2 ATP + H+ Leak + Transport Cost

Eukaryote = 30-32 ATP, Prokaryote = 38 ATP = No Shuttle Cost

### *6. FERMENTATION = Anaerobic* `Cytoplasm`

*A. Alcoholic Fermentation = Yeast*

Pyruvate → Pyruvate Decarboxylase + TPP → Acetaldehyde + CO2

Acetaldehyde + NADH → Alcohol Dehydrogenase → Ethanol + NAD+

Net = Glucose → 2 Ethanol + 2 CO2 + 2 ATP

Use = Wine, Beer, Bread = Bubbles = CO2

*B. Lactic Acid Fermentation = Muscle/Plant*

Pyruvate + NADH → Lactate Dehydrogenase → Lactic Acid + NAD+

Net = Glucose → 2 Lactic Acid + 2 ATP

Use = Curd = Lactobacillus, Muscle Cramp = O2 Debt

*Figure 6: Fermentation*

Glucose 6C

   ↓ Glycolysis

2 Pyruvate 3C + 2 NADH + 2 ATP

   ↓ No O2

   /          \

Yeast        Muscle

 ↓            ↓

Ethanol    Lactic Acid

 + CO2      + Regenerate NAD+

### *7. AMPHIBOLIC PATHWAY* `Respiration = Breakdown + Synthesis`

Catabolic = Glucose → CO2 = Energy Release = Respiratory Substrate

Anabolic = Intermediates Used = Acetyl CoA → Fatty Acid, α-KG → Amino Acid, OAA → Aspartate

So Respiration = Amphibolic = Both Catabolic + Anabolic

### *8. RESPIRATORY QUOTIENT = RQ* `CO2/O2`

RQ = Volume CO2 Released / Volume O2 Consumed

Carbohydrate = C6H12O6 + 6O2 → 6CO2 = RQ = 6/6 = 1

Fats = Tripalmitin = C51H98O6 + 72.5O2 → 51CO2 = RQ = 51/72.5 = 0.7

Proteins = RQ = 0.9

Organic Acid = Malic = C4H6O5 + 3O2 → 4CO2 = RQ = 4/3 = 1.33 > 1

Anaerobic = RQ = ∞ = No O2 Use, CO2 Release

Succulents = RQ = 0 = No CO2 Release = Night Acid Store

### *9. FACTORS AFFECTING RESPIRATION*

1. Temperature = Q10 = 2-3 = 0-30°C Increase, 30-40°C Decrease = Enzyme Denature

2. O2 = Extinction Point = Min O2 for Aerobic, Below = Anaerobic

3. CO2 = High CO2 = Inhibit = Stomata Close

4. Water = Dry Seeds = Low, Imbibition = High

5. Light = No Direct Effect, Indirect = Stomata Open

6. Injury = Wound Respiration = High Rate

### *10. PYQ HOTSPOTS 2017-2024* 🔥

1. *Net ATP Aerobic* = 36/38 Theory, 30-32 Actual = NEET 2024

2. *RQ of Fat* = 0.7, Carbohydrate = 1, Organic Acid > 1 = NEET 2024

3. *PFK* = Rate Limiting Glycolysis + Allosteric = NEET 2023

4. *Complex IV* = Cyt c Oxidase + O2 → H2O = NEET 2023

5. *Krebs Cycle Location* = Mitochondrial Matrix = NEET 2022

6. *Fermentation* = Yeast = Ethanol + CO2, Muscle = Lactate = NEET 2022

7. *Chemiosmosis* = Peter Mitchell + H+ Gradient + F0-F1 = NEET 2021

8. *NADH = 3 ATP, FADH2 = 2 ATP* = NEET 2021

9. *Link Reaction Product* = Acetyl CoA + CO2 + NADH = NEET 2020

10. *Amphibolic Pathway* = Catabolic + Anabolic = NEET 2020

11. *Succinate Dehydrogenase* = Complex II + Inner Membrane = NEET 2019

12. *Glycolysis Net Gain* = 2 ATP + 2 NADH = NEET 2019

13. *Photorespiration* = No ATP = Wasteful = NEET 2018

14. *C4 Plants ATP* = 30 ATP + 12 NADPH = NEET 2018

15. *RQ Infinite* = Anaerobic Respiration = NEET 2017

### *11. GOOGLE SE HATKE TRICKS* 🧠

*A. ATP Yaad Karne Ka*

Glycolysis = 2 ATP + 2 NADH = 8 ATP

Link = 2 NADH = 6 ATP

Krebs = 2 ATP + 6 NADH + 2 FADH2 = 24 ATP

Total = 8 + 6 + 24 = 38 ATP

Trick: **8-6-24** = **38** = Date Yaad Kar Lo

*B. Krebs Cycle Enzymes*

**C**itrate **S**ynthase → **A**conitase → **I**socitrate **D**H → **α-KGDH** → **S**uccinyl **C**oA **S**ynthetase → **S**uccinate **D**H → **F**umarase → **M**alate **D**H

Trick: **C**hacha **S**e **A**am **I**mli **D**ekar **A**ao **S**amose **C**hatni **S**ath **F**ir **M**ango

*C. ETS Complex*

I = NADH DH, II = Succinate DH, III = Cyt bc1, IV = Cyt c Oxidase, V = ATP Synthase

Trick: **I** **N**eed **3** **C**ups **O**f **A**tla**S**

*D. RQ Values*

Carb = 1 = Normal, Fat = 0.7 = Kam, Protein = 0.9, Organic Acid = >1 = Zyada

Anaerobic = ∞ = O2 Zero

Trick: **C**arbohydrate **1**, **F**at **0.7**, **O**rganic **A**cid **>1**

*Diagrams for Board*:  

1. Glycolysis, 2. Krebs Cycle, 3. ETS, 4. Mitochondria, 5. Fermentation  

Respiration Summary Table

Process	Location	ATP Gain
Glycolysis	Cytoplasm	2 ATP
Krebs Cycle	Mitochondria	2 ATP
ETS	Cristae	32-34 ATP

🔥 Respiration Quick Revision Table

Process	Location	ATP Gain
Glycolysis	Cytoplasm	2 ATP
Krebs Cycle	Mitochondria	2 ATP
ETS	Cristae	32-34 ATP

💡 Yaad Rakh: Total ATP = 36-38 ATP per Glucose