Cellular Respiration

Chapter 9

Chemical Energy

There are many pathways cells can use to release energy from compounds

In the presence of oxygen there are many high-energy options

Without oxygen there are still options, but fewer

All those CALORIES!!!

One gram of sugar can be “burned” to produce 3811 calories of heat energy

One calorie is the amount of energy needed to raise the temperature of 1 gram of water 1 degree Celcius

Cells don’t actually “burn” glucose but release the energy slowly through cellular respiration

Cellular Respiration6O2 + C6H12O6 6CO2 + H2O + Energy

Oxygen + Carbon dioxide + water Glucose + ENERGY!!

ATP!!!

Adenosine triphosphate When a cell has energy available it stores it

by adding a third phosphate group onto ADP to make ATP

Breaking the bond of the third phosphate group on ATP releases energy

ENERGY!!ENERGY!!

Step 1: Glycolysis

Happens with or without oxygen 2 ATP required to run Glycolysis 4 ATP come out of the reaction Glucose is broken in half into 2

molecules of pyruvic acid and a 3-carbon compound

Glycolysis

Glucose

Pyruvic Acid

Pyruvic Acid

3

Carbon

Compound

ATP Balance

ATP!

ATP!

Glycolysis

ATP!

ATP!

ATP!

ATP!

ATP production is small, but so fast that it can produce thousands of molecules of ATP in a few milliseconds

NADH

As Glycolysis runs, it passes extra electrons to NAD+ which produces NADH

When the cell has turned all of the NAD+ molecules into NADH there are no more electron receptors and Glycolysis can no longer continue

Aer sweet AER!

Aerobic energetic reactions take place in the mitochondria to produce LOADS of ATP

Mr. Kreb and the Oranges

First compound formed in Krebs Cycle is citric acid

Begins when pyruvic acid enters the mitochondrion

Kreb’s Cycle produces all of the CO2

you will ever exhale from your body

Krebs Cycle

Pyruvate goes in

4 NADH, 1 FADH2, 1 ATP, and 2 CO2 come out

Electron Transport

The Electron Transport chain received high energy molecules (charged with high energy electrons) from Mr. Kreb

Molecules are passed from receptor to receptor, stepping down the energy level and releasing electrons to carriers inside the mitochondrion.

E- Transport

At the end of the chain there is an enzyme that combines low energy electrons with hydrogen ions and oxygen to form water.

H+ ions are built up in the inner membrane through the transport process making it positively charged

E- Transport

H+ ions can be allowed to pass through protein channels in the cellular membrane turning the ATP synthases.

The movement of the H+ ions provides the energy to attach the third phosphate onto the ADP molecule and form ATP

Transport Those e- !!

ATP Synthase- Cell Turbine

http://fig.cox.miami.edu/~cmallery/150/makeatp/makeatp.htm

F1 motor of ATP synthase uses the power of rotational motion to build ATP. Left conformation is the one connected with ADP binding. Right conformation is connected with ATP release.

(computed @ rasmol)

http://upload.wikimedia.org/wikipedia/commons/thumb/c/c9/Atp_synthase_pt.png/450px-Atp_synthase_pt.png

Creatine Phosphate