Cellular Respiration

WE NEED ENERGY!

What is it?

Process where the mitochondria breaks down food molecule to produce ATP

Cellular Respiration

Aerobic Respiration Anaerobic Respiration

Requires oxygen to occur Occurs in the absence of oxygen

Alcohol Fermentation Lactic Acid Fermentation

3 Steps: - Glycolysis - Krebs - ETC

The Phases of Respiration

We will talk about each 1 in detail… Glycolysis Formation of Acetyl-CoA Citric Acid Cycle (AKA Krebs Cycle) Electron Transport Chain

Glycolysis Series of chemical

reactions in the cytoplasm that break down glucose into 2 molecules of pyruvic acid

In order for glycolysis to occur requires 2 ATPs

The end result 4 ATPS are produced NOT A VERY EFFECTIVE

PROCESS! NAD+ (electron carrier)

accepts 2 electrons to form 2 NADH + 2H+

The products: 2 molecules of pyruvic

acid

2 NADH

2 ATPs (WHY?)

Formation of Acetyl-CoA

This is an intermediate step Following glycolysis, pyruvic acid is

transported to the mitochondria and undergoes a series of reactions

The Results of these reactions: Pyruvic acid (3 carbons) is split apart gives off

CO2. Remaining 2 carbon molecule combines with

Coenzyme A to produce Acetyl-CoA Produces another molecule of NADH and H+

Citric Acid Cycle

Also called the Krebs Cycles Series of chemical reactions

(similar to the Calvin Cycle). The molecule used in the first reaction is also the end product

The products for every turn (must turn 2 times): 1 ATP x 2 = 2ATPs

2 CO2 x 2 = 4 CO2

3 NADH + 3H+ x 2 = 6NADH + 6H+

1FADH2 x 2 = 2FADH2

Electron Transport Chain

Occurs in the inner membrane of the mitochondria

Electron Transport Chain

Final electron acceptor = OXYGEN Reacts with 4 H+

ions and 4 electrons to produce 2 H2O

Without oxygen, the proteins in the transport chain cannot pass electrons

The Products: 32 ATP 2 H2O

Aerobic Respiration Products

Carbon DioxideWater36 ATPs

Anaerobic Respiration

Recall: occurs without oxygen Also referred to as fermentation

There are certain instances (ie: during heavy exercise), when your cells are without oxygen for short periods of time

Fermentation follows glycolysis to produce ATP until oxygen is available again

Lactic Acid Fermentation

Supplies energy while oxygen is scarce 2 molecules of pyruvic acid produced in

glycolysis use NADH to form 2 molecules of lactic acid Lactic acid is transferred to the muscles

Builds up as your muscles fatigue

Recall 2 molecules of ATP are produced during glycolysis. As a result, lactic acid fermentation also produces 2 ATPs!

Lactic Acid Fermentation

Alcohol Fermentation

Used by yeast cells and some bacteria to produce CO2 and ethyl alcohol

Often occurs during baking: Bread making: yeast cells produce CO2

bubbles in the dough as it bakes The bubble pockets are left to lighten the

bread

Alcohol Fermentation