Unit II, Chapter 25 pg 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 2 nd and 3 rd 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 CO H 2 O & energy Generates heat and 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 FADH 2, containing ________________ GTP, which ___________ to make ATP CO 2  bloodstream and ________ at lungs 6 CO 2 made for every glucose So, how do we get ATP?....

1 glucose yields ATP 3 NADH + 3 H+  e- transport = 9 ATP 1 FADH 2  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  H 2 O) _____________- 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 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 _______________