Unit II, Chapter 25 pg 950-971 selected portions Glycolysis, Krebs cycle, Electron Transport Chain,...

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

Forming bonds _____________________ Breaking the bond between the 2nd and 3rd

P group results in energy liberation 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 Oxidation of glucose = cellular respiration

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+ 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 non-

carbohydrate sources

Stimulated by _______________ from adrenal cortex

Also causes proteins amino acids

_______________ from pancreas _______________