Transcript Chapter 25
Unit II, Chapter 25 pg 950-971
selected portions
Glycolysis, Krebs cycle, Electron
Transport Chain, ATP stores potential
energy
Some cell processes req’ring energy
Na+/K+ pump
(as any active transport process)
Power stroke of skeletal muscle
Glycolysis
Flagellar motility
Microtubule movement during cell division
ATP is a high energy molecule
Phosphorylation of ADP increase its PE
Breaking the bond between the 2nd and 3rd
P group results in energy liberation
Forming bonds _____________________
ATP ADP
ATPase – enzyme, catalyzes _________
bond, creating ADP
________ ________ is used do work
Linking catabolism & anabolism
Oxidation & reduction rxns
_______________- removal of electrons, or H+
decrease potential energy content
Usually exergonic – releases energy
Cmpds such as glucose (reduced) have lots of H
contain more chemical P.E. than the oxidized cmpds
________________- addition of e- or H+
Oxidation of glucose = cellular respiration
increase of energy content of molecule
Oxidation & reduction rxns are always coupled
Cellular respiration
___________________ to produce ATP
To attach a phosphate group to ADP to produce
ATP ____________ energy
Series 4 reactions in presence of oxygen produces
more ATP than when oxygen is absent:
Glycolysis
Acetyl Coenzyme A formation
Krebs cycle
Electron Transport Chain
Cellular respiration (2)
__________ cellular respiration- oxygen absent
glucose breakdown, catabolic rxns 2 pyruvic acid
This process is called glycolysis
1 glucose yields 2 ATP
happens in cytosol
____________- in presence of oxygen
Glycolysis + rxns 6 CO2 + 6 H2O & energy
Generates heat and 36-38 ATP
happens in mitochondria
Overview of
cell respiration
(oxidation of
glucose)
Glycolysis – 10 steps, fig 25.4
Rxn generates 4 ATP & 2 pyruvic acid*
Net gain:
2 ATP = metabolic energy
2 NADH = intermediate for e- transport chain
2 H+ = intermediate for e- transport chain
* Oxygen _______, pyruvic acid mitochondria
for Krebs cycle and ETC
* Oxygen _______, pyruvic acid likely converted
to lactic acid via anaerobic resp in cytosol
Lactic acid liver to be converted to glucose
Fate of pyruvic acid
Oxygen present
mitochondria,
becomes CoA and
goes to Krebs
Oxygen absent –
converted to lactic
acid in cytosol
(lactic acid
bloodstream liver
where it is converted
back to pyruvic acid)
3 main results of Krebs cycle
reduced coenzymes NADH + H+ and
FADH2, containing ________________
GTP, which ___________ to make ATP
CO2 bloodstream and ________ at lungs
6 CO2 made for every glucose
So, how do we get 36-38 ATP?....
1 glucose yields 36-38 ATP
3 NADH + 3 H+ e- transport = 9 ATP
1 FADH2 e- transport = 2 ATP
1 ATP from GTP conversion
Multiply the above results by 2 because 2 Acetyl
CoA come from one glucose!
2 NADH produced during glycolysis produce 4-6
ATP
2 NADH produced during Acetyl CoA formation
also produce 6 ATP
2 ATP from glycolysis
Electron Transport Chain
Series of electron carriers (proteins called
_________) in the inner mitochondrial membrane
Each carrier is reduced then oxidized
Rxns are exergonic & energy is _____ to make ATP
In aerobic resp, final e- acceptor is oxygen (gets
reduced H2O)
_____________- links chemical rxn w/H+ pump
Electron Transport Chain (2)
Proton pumps send H+ from matrix to
intermembrane space
Creates a gradient, H+ gets build up in the
intermembrane space
H+ flow back to the matrix (by proton
motive force) through a channel in ATP
synthase
ATP synthase adds a P to ADP ATP
Summary of cellular
respiration, fig 25.10
See also table 25.1
page 962
Proteins & fats glucose
Amino acids, glycerol, & lactic acid can be
converted to glucose – ____________________
Process by which glucose is created from noncarbohydrate sources
Stimulated by
_______________ from adrenal cortex
Also causes proteins amino acids
_______________ from pancreas
_______________