Powerpoint Metabolisme 2

BYDHITA AYU PERMATA SARI, S.PD.

STATE UNIVERSITY OF SURABAYA

CELLULAR RESPIRATION

Cellular Respiration

Cellular Respiration is the process that

releases energy by breaking down food

molecules in the presence of oxygen.

6O2 + C6H12O6 6CO2 + 6H2O + Energy

Oxygen + Glucose Carbon Dioxide + Water

+ Energy

Cellular Respiration

Glycolysis takes place in the cytosol of cells.

Glucose enters the Glycolysis pathway by conversion to glucose-6-phosphate.

Initially there is energy input corresponding to cleavage of two ~P bonds of ATP.

Glycolisis

H O

OH

H

OHH

OH

CH2OPO32

H

OH

H

1

6

5

4

3 2

glucose-6-phosphate

Fermentation

Releases energy from glucose without the presence of oxygen.

There are two types of fermentation: alcoholic and lactic acid.

Alcoholic fermentation is done by yeasts and some microorganisms. It produces alcohol & Carbon Dioxide

Lactic Acid is produced by muscles during rapid exercise when the body cannot supply enough oxygen.

Aerobic Respiration

1. Includes the Krebs Cycle & the Electron Transport Chain

2. Pyruvic acid from glycolysis diffuses into matrix of mitochondria & reacts with coenzyme A to form acetyl-CoA (2-carbon compound)

3. CO2 and NADH are also produced

Krebs Cycle

Occurs in the matrix of the mitochondrion

During the Krebs Cycle, pyruvic acid is

broken down into carbon dioxide in a series

of energy-extracting reactions.

Citric Acid is created in this cycle thus giving

it the nickname Citric Acid cycle.

Net ATP Production is 2 ATP.

2-carbon acetyl CoA joins with a 4-carbon compound to form a 6- carbon compound called Citric acid

Citric acid (6C) is gradually converted back to the 4-carbon compound -ready to start the cycle once more

The carbons removed are released as CO2

-enzymes controlling this process called decarboxylases

The hydrogens, which are removed, join with NAD to form NADH2 -enzymes controlling the release of hydrogen are called dehydrogenases

Krebs Cycle

The electron transport chain uses the high-energy electrons from the Krebs

Cycle to convert ADP to ATP.

Contains 4 protein-based complexes that work in sequence moving

H+ from the matrix across the inner membrane (proton pumps)

A concentration gradient of H+ between the inner & outer

mitochondrial membrane occurs

H+ concentration gradient causes the synthesis of ATP by

chemiosmosis

Energized e- & H+ from the 10 NADH2 and 2 FADH2 (produced during

glycolysis & Krebs cycle) are transferred to O2 to produce H2O

(redox reaction)

O2  +  4e-  +  4H+  2H2O

Electron Transport Chain

Electron Transport Chain

Net Product from Cellular Respiration

Stage NADH FADH ATP Number of ATP

Glycolisis 2 2 6

Oxidative decarboxilation

2 0 0 6

Krebs Cycle 6 2 2 24

Total 36

Cellular Respiration