Chapter 7: Cellular Respiration

importance of electrons in the transfer of energy in living systems

they carry chemical energy to molecules which allows life to capture, store, and release energy

how ATP is used by a cell as an energy source

ATP allows a cell to story energy safely and release it only when needed

ATP cycle

ATP + H2O = ADP + phosphate group = ATP + H2O

2 ways to make ATP

substrate level phosphorylation and oxidative phosphorylation

substrate level phosphorylation

no required oxygen, enzyme transfers a phosphate directly from a substrate to ADP, makes 4 ATP

oxidative phosphorylation

requires oxygen, transfers electrons through electron transport chain and then into ATP synthase to make ATP, makes 32-34 ATP

glycolysis

breakdown of one molecule of glucose

products of glycolysis

2 pyruvate molecules, net gain of 2 ATP, 2 NADH molecules

circular pathways

start with a molecule that is regenerated at the end, citric acid cycle

linear biochemical pathways

start with a molecule and end with a different molecule, glycolysis

breakdown of pyruvate step 1

pyruvate loses 1 carbon to turn into 2-carbon

breakdown of pyruvate step 2

2-carbon is oxidized, NAD+ turns into NADH

breakdown of pyruvate step 3

oxidized 2-carbon is attached to coenzyme A, forming acetyl-CoA

electron transport chain

electron passes through plastoquinone (pq), cytochrome C (cyt), and plastocyanin (pc), its energy decreases as it passes through

proton pumping

energy from electron transport chain pumps H+ ions into intermembrane space creating a high H+ concentration outside and a low H+ concentration inside

difference between anaerobic cellular respiration and fermentation

anaerobic cellular respiration uses an ETC with a non-oxygen final acceptor and fermentation does not use an ETC

fermentation that occurs in animal cells

lactic acid fermentation