2c. Cellular Respiration Flashcards
Anaerobic respiration that happens in cytosol
glycolysis
4 metabolic stages
glycolysis
pyruvate oxidation
krebs cycle
electron transport chain
happens in mitochondria and requires oxygen
aerobic respiration
C6H12O6 + 6O2 =
ATP + 6H2O (+heat)
step-by-step breakdown of high energy glucose molecules to release energy
cellular respiration
splitting of sugar
glycolysis
migration from cytosol to matrix
grooming phase
also called chemiosmosis and happens in inner mitochonrial membrane
Electron Transport Chain and Oxidative Phosphorylation
energy currency of cells
ATP
What happens when a phosphate group is pulled away during a chemical reaction?
energy is released
this cycle is the fundamental mode of energy exchange in biological systems
ATP-ADP Cycle
how many ATP is produced for every 1 glucose
2 ATP
first cells had no organelles
prokaryotes
glycolysis
convert:
produces:
consumes:
net:
convert glucose (6C) to 2 pyruvate (3C)
prduces 4 ATP & 2 NADH
consumes 2 ATP
net 2 ATP & 2 NADH
1st half of glycolysis is called
glucose “priming”
what happens during priming
- get glucose ready to split
- split destabilized gl
ucose
what is the 2nd half of glycolysis
energy harvest
what happens during energy harvest
- NADH production
- ATP production
what happens during NADH production
- G3P donates H
- oxidize sugar
- reduce NAD+
- NAD+ to NADH
what happens during ATP production
- G3P to pyruvate
- PEP sugar donates P
*ADP to ATP
DHAP
dihydroxyacetone phosphate
G3P
glyceraldehyde-3-phosphate
In the last steps of glycolysis, where did the P
come from to make ATP?
the sugar substrate (PEP)
P is transferred
from
§ kinase enzyme
§ ADP - ATP
PEP to ADP
5 reactions of glucose priming
hexokinase
phosphoglucose isomerase
phosphofructokinase
aldolase, isomerase
glyceraldehyde-3-phosphate dehydrogenase
5 reactions for energy harvest
phosphoglycerate kinase
phosphoglyceromutase
enolase
pyruvate kinase
How ATP is formed?
formed when an enzyme transfers a phosphate group from a substrate to ADP
more carbons to strip off =
more energy to harvest
glycolysis plits a glucose
molecule into
2 - 3 Carbon
molecules called
pyruvate
glycolysis products
2 ATP, NADH and pyruvate
How is NADH recycled to NAD+?
another molecule must accept
H from NADH
• with oxygen
aerobic respiration
• without oxygen
anaerobic respiration
fermentation
Fermentation is an aerobic process
• bacteria, yeast
pyruvate - __ + __
pyruvate - ethanol + CO2
3C. 2C. 1C
animals, some fungi
pyruvate - __
pyruvate + lactic acid
3C. 3C
to glycolysis
dead end process
at estimately what percent of ethanol kills yeast
12
alcohol fermentation can’t reverse reaction
.
reversible process
once O2 is available,
lactate is converted
back to pyruvate by
the liver
allow H+ to flow
through ATP synthase
ATP synthase
ADP + Pi - ___
ATP
Pyruvate enters mitochondria
3 step oxidation process
•releases 1 CO2 (count the carbons!)
•reduces 2 NAD - 2 NADH (moves e-
)
•produces acetyl CoA
Acetyl CoA enters Krebs cycle
Oxidation of Pyruvate
Pyruvate oxidized to Acetyl CoA
2 x [
Yield = 2C sugar + NADH + CO2]
Energy accounting of Krebs cycle
Net gain = 2 ATP
= 8 NADH + 2 FADH2
If the yield is only 2 ATP then how was
the Krebs cycle an adaptation?
– value of NADH & FADH2
• electron carriers & H carriers
– reduced molecules move electrons
– reduced molecules move H+ ions
• to be used in the Electron Transport Chain
series of molecules built into inner
mitochondrial membrane
• along cristae
• transport proteins & enzymes
electron transport chain
how many ATP yields from ETC from 1 glucose
34 ATP
what “pulls” the
electrons down the ETC?
oxidative phosphorylation
Stripping H from Electron Carriers
NADH passes electrons to ETC
Allow the protons
to flow through
ATP synthase
proton-motive force
The diffusion of ions across a membrane
chemiosmosis
Proposed chemiosmotic hypothesis
Peter Mitchell
What is the final
electron acceptor in Electron Transport
Chain?
O2
