Download I. Cellular Respiration – complex process in which cells make ATP

I.
Cellular Respiration – complex process in which cells make ATP by breaking
down organic compounds
A. Anaerobic respiration (without oxygen)
(enzyme)
Glucose + 2 ATP  2 pyruvic acid + 4 ATP
1. Glycolysis – is a pathway in which glucose is oxidized into pyruvic acid
a. takes place in cytoplasm
b. produces two 3 carbon molecules of pyruvic acid
c. net of 2 ATP produced
2. Lactic Acid – enzyme converts pyruvic acid into lactic acid (another 3
carbon compound)
a) forms NAD+ which can be used to keep glycolysis going to make
more ATP
B. Aerobic Respiration (oxygen present)
(enzyme)
C6H12O6 + 6O2  6H2O + 6CO2 + 36 ATP
(glucose) (oxygen) (water) (carbondioxide)
1. Krebs Cycle – energy pathway that breaks down acetyl CoA producing
CO2, hydrogen atoms + ATP
a) 2 pyruvic acids convert to citric acid
b) citric acid releases CO2 molecule & H atom to form a 5 carbon
compound. The H atom combines with NAD to form NADH
c) 5 carbon compound releases CO2 & H to form 4 carbon compound
- again NAD becomes NADH
- ATP is made from ADP
d) 4 carbon compound releases H to form another 4 carbon compound
H atom combines with FAD to make FADH2
e) 4 carbon compound releases H atom to form oxaloacetic acid, which
keeps the krebs cycle going
- NAD converted to NADH
f) repeats cycle 1 more time due to the fact that there was 2 pyruvic acids
g) 2 ATP are produced
2. Electron Transport Chain – second stage of aerobic respiration
a) takes place in inner membrane of mitochondria, ATP is produced by
the electron transport chain when NADH & FADH2 release H atoms
regenerating NAD+ & FAD
b) this causes high energy levels of the electrons in the H atoms
c) the electrons are passed along a series of molecules, where the
electrons lose energy
d) the energy lost is used to pump the protons to the other side of the
membrane
e) this causes 34 ATP to form from ADP & phosphate
II.
Activity – chemical energy is stored as C, F, & P. The body can not use these
organic compounds as immediate energy. They must be converted into ATP
(adenosine triphosphate), a high-energy compound. Another compound, CP
(creatine phosphate) serves to replace ATP as it is used up.
A. 3 types of energy transfer systems needed for activity
1. Immediate Energy – ATP-CP
- anaerobic
- energy comes from ATP stored in cell and then resynthesized by
CP
- activities less than 10 seconds
- produce ATP rapidly but not for long duration
2. Short term energy
- energy comes from ATP formed when carbohydrates are broken
down into lactic acid in the absence of oxygen
- max activities of 1-2 min (i.e. quarter mile run)
- produces ATP rapidly
3. Long term energy
- Carbohydrates combine with oxygen to produce ATP
- In longer activities that are sub maximal and oxygen present
- Produce ATP at slower rate but can sustain production for long
time
B. Most exercises use combination of the three
C. 25% of energy produced goes to activity and 75% is released as heat