Cellular Respiration Flashcards
Aerobic Respiration
catabolic process where oxygen is the final electron receptor (taking energy from food, transferring to ATP in the presence of O2)
Anaerobic Respiration
same as aerobic respiration, only without oxygen = fermentation (makes ATP only no oxygen)
To build ATP…
move electrons from fuel to intermediates to redox reactions (reactions where oxidation and reduction takes place)
How do we harvest energy from fuels?
Digest larger molecules into smaller ones ( break bonds and move electrons from one molecule to another )
OIL
Oxidation is Loss (loses electrons - becomes positive charged)
RIG
Reduction is Gain (gains electrons - becomes negatively charged)
Oxidation
a substance loses electrons or is oxidized
Reduction
a substance gains electrons or is reduced the amount of positive charge is reduced)
Reducing agent
electron donor
Oxidizing agent
electron receptor
why is oxygen good at oxidizing
oxygen is electronegative (electron hog)
Electron Transport Chain
series of molecules in inner mitochondrial membrane. Shuttle electrons, capture them with oxygen after “falling downhill”
allows for the controlled transfer of electrons to regulate how energy is used.
powers pumping H+ against its concentration gradient pumps more H+ into intermembrane space
NAD+ and NADH
NAD+ oxidized form, gets electrons becomes reduced to NADH
Cellular respiration
energy out of your food onto ATP
Harvesting Energy from Glucose (3 steps)
1) break down glucose into two molecules or pyruvate
2) Pyruvate oxidation and citric acid cycle
3) Oxidative phosphorylation
Substrate level phosphorylation
ATP production via direct enzymatic phosphorylation
( only accounts for a small amount)
Oxidative Phosphorylation
Couple the electron transport chain with the “downhill” H + movement to produce ATP
( accounts for 90% of ATP production)
Aerobic respiration (O2 present)
Cellular Respiration:
- complete oxidation
- waste products: H2O and CO2
- net energy trapped per glucose ( 32 ATP)
Anaerobic respiration ( O2 absent)
fermentation:
- incomplete oxidation
- waste products: lactic acid (ethanol) and CO2
- Net energy trapped per glucose (2 ATP)
The Citric Acid Cycle (Krebs Cycle)
If O2 is present –> citric acid cycle
Take pyruvate from glycolysis –> multi step process in mitochondria
Steps between glycolysis and Citric Acid Cycle (intermediate steps)
Pyruvate is oxidized to Acetyl CoA
releases CO2
Reduced 1 NAD+ to NADH + H+
role of NADH
transfers electrons from glucose to further the process of making ATP
As an electron falls…
energy is released
chemiosmosis
proton motive force powers ATP synthesis
Electron transport chain + chemiosmosis
Oxidative Phosphorylation
Steps of cellular respiration summed up
break down glucose
shift electrons from glucose
feed it into the citric acid cycle, get all electrons off
use the electrons to power ATPsynthase machine
2 types of fermentation
lactic acid and alcohol
