When is ATP Made in the Body?

During a Process called Cellular Respiration that takes place in both Plants & Animals & Prokaryotes

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Cellular Respiration Overview

At this point life diverges into two forms and two pathways– Anaerobic cellular respiration (aka fermentation)– Aerobic cellular respiration

Cellular Respiration Overview

• Transformation of chemical energy in food into chemical energy cells can use: ATP

• Breakdown of one glucose can result in 36 ATP molecules

Overall Reaction:C6H12O6 + 6O2 → 6CO2 + 6H2O

Where Does Cellular Respiration Take Place?

• It actually takes place in two parts of the cell:

Glycolysis occurs in the Cytoplasm

Krebs Cycle & ETC Take place in the Mitochondria

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Glycolysis Diagram

(page 128)

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Glycolysis Summary-Takes place in the Cytoplasm (all cells- prokaryotes)

-Anaerobic (Doesn’t Use Oxygen)

-Requires input of 2 ATP

-Glucose split into two molecules of Pyruvate or Pyruvic Acid

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•Also produces 2 NADH and 4 ATP

Fermentation

Occurs when O2 NOT present (anaerobic)

Called LACTIC ACID FERMENTATION-in muscle cells (makes muscles tired)

Called ALCOHOLIC FERMENTATION-in yeast (produces ethanol)

Gains only 2 ATP from each Pyruvic acid

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Entering the MITOCHONDRIA

• Pyruvic acids ( 3 carbon atoms) from glycolysis- turn into Acetyl CoA (2 carbon atoms) as they enter the mitochondria.

• This produces 1 NADH each

Krebs Cycle

ATP

NETS: 3NADH, 1ATP, 1FADH2, & 2CO2Copyright Cmassengale

Krebs Cycle

Step 1- Acetyl CoA combines with a 4 carbon molecule to produce citric acid (6 carbons)

Kreb’s Cycle

Step 2- Carbon is removed (CO 2) and energy is produced– NADH

Step 3-4 See step 2--- produces ATP and NADH

Kreb’s Cycle

• Step 5- Oxaloacetic acid is used to combine with Acetyl CoA to restart the cycle

Krebs Cycle Summary• Requires Oxygen (Aerobic)• Completes the breakdown of glucose• Turns twice per glucose molecule• Therefore, For each Glucose molecule, the

Krebs Cycle produces 6NADH, 2FADH2, 4CO2, and 2ATP

Takes place in matrix of mitochondria

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Electron Transport Chain (pg136)

Electron Transport Chain Summary

• Occurs Across Inner Mitochondrial membrane• FADH, and NADH donate electrons for the

chain• NADH = 3 ATP’s• FADH2 = 2 ATP’s• Oxygen is the last electron acceptor and

combines with H+ to make water• 34 ATP Produced

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Energy Tally

2 ATP for anaerobic vs 36 ATP for aerobic

– Glycolysis 2 ATP (anaerobic)

– Kreb’s 2 ATP (aerobic)

– Electron Transport 34 ATP (aerobic) 38 ATP

• Anaerobic organisms can’t be too energetic but are important for global recycling of carbon

CALORIE

• Defined as the amount of energy needed to raise 1 gram of water 1 degree Celsius.

• 4.2 Joules

KILOCALORIES (Large Calorie) Food Calorie

• 1 kilocalorie equals 1000 calories

• We measure food calories in the unit of KILOCALORIES although we only call it a CALORIE.

• The complete oxidation of a glucose molecule will yield 686 kcal.

• ATP requires 12 kcal to be formed

CALCULATING ENERGY YIELD

• EFFICIENCY of glycolysis =Energy Required to make ATP x 100

• Total energy possible (686 kcal)

• Glycolysis is only 3.5 % efficient

• 2 ATP x 12 kcal x 100 • 686 kcal

CALCULATING ENERGY YIELD

Complete Aerobic Respiration is 66% efficient

38 ATP x 12 kcal x 100 = 66 686 kcal