BY DHITA AYU PERMATA SARI, S.PD. STATE UNIVERSITY OF SURABAYA CELLULAR RESPIRATION
May 11, 2015
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