How are breathing and C.R. related?

How is energy created in a controlled manner?

• Oxygen acts as the final “e- acceptor”

• WHY?– Oxygen has a – charge– Attracts 2 + charged H+

Electron Transport Chain

• Driven by Oxygen (which is the electron acceptor)

• Instead of one quick release of a massive amount of energy (lost as light and heat) energy is released in small amounts

• GATP is converted to ADP by losing a phosphate

giving off ENERGY.

Cellular respiration

C6H12O6 + 6O2 6CO2 + 6H2O + ATP

What is metabolism?

• All of the cellular processes that occur within your body (breaking down or building up chemical compounds)

• Cellular respiration is a metabolic pathway because it is a long series of reactions that are carried out to complete a process.

• Where does most of the metabolic pathway of cellular respiration take place?– MITOCHONDRIA

3 stages of Cellular Respiration

STAGE 1: GLYCOLYSIS• Energy investment

stage because it uses an initial input of 2 ATP

• Creates 4 ATP• Net gain of 2 ATP• Sugar splitting stage

because it splits 1 glucose molecule into 2 pyruvate

4 ATP- 2 ATP 2 ATP

Recap of Glycolysis

• Location– Cytoplasm

• Energy invested– 2 ATP

• Net gain of ATP– 2 ATP

• Starting material– Glucose

• Ending material– 2 pyruvates

• (pyruvic acid)

• Total # of NADH– 2 NADH

Stage 2: Krebs Cycle Pyruvate must be converted to acetyl CoA to enter Krebs by losing a CO2 (paying toll)

Since glucose splits into 2 pyruvate: each glucose molecule goes through the cycle 2 times

3 water molecules created per pyruvate

3 CO2 per pyruvic acid

Quick Recap of the Kreb’s Cycle

• How many turns of the cylce per glucose?– 2

• Per turn # of each created– ATP

• 1

– FAHD2

• 1

– NADH• 1 in creating acetly CoA• 3 per turn of Krebs

• Total energy molecules– 2 ATP– 2 FADH2

– 8 NADH

• Byproducts include– 2 CO2 per turn so 4 total

CO2

– 1 CO2 creating acetyl CoA so total of 6 CO2

Electron Transport Chain

NADH = 3 ATP

FADH2 = 2 ATP

Final e- acceptor

OVERALL

• NADH in glycolysis = 2 x 3 = 6 ATP• NADH in Krebs = 4 x 2 turns = 8 x 3 = 24 ATP• FADH2 in Krebs = 1 x 2 turns = 2 x 2 = 4 ATP• ATP in glycolysis = 2 ATP• ATP in Krebs = 1 x 2 turns = 2 ATP• TOTAL ATP = 38 ATP

Anaerobic Respiration

• Reactions do not require oxygen to proceed.• When anaerobic respiration takes place in

cells it is referred to as – Fermentation: energy production in a cell under

aerobic conditions• Sugar alcohol• Sugar lactic acid

Alcohol Fermentation

Powered from NADH created during Glycolysis

The NAD+ created in fermentation is used to fuel the process

Lactic acid fermentation

• Converts pyruvate into lactic acid.• Occurs in muscle cells and bacteria.• Fueled by the NAD+ made during

fermentation.