Chapter 9 Flashcards
Energy flow
-into ecosystem as sunlight and leaves as heat
-cells use chemical energy stored in organic molecules to regenerate atp which powers work
Photosynthesis
-generates O2 and organic molecules which are used in cellular respiration
Why organic molecules have potential energy
the arrangement of the electrons in the bonds between their atoms
Respiration in cellular respiration
-both aerobic and anaerobic but often used to refer to aerobic respiration
Exergonic
-breakdown of organic molecules
-produce energy some of which can be used for work
Aerobic respiration
-consumes organic molecules and O2 and yields ATP
Fermentation
-partial degradation of sugars that occurs without O2
-uses substrate level phosphorylation instead of electron transport chain to generate atp
-consists of glycolysis plus reactions that regenerate nad+ which can be reused by glycolysis
Anaerobic respiration
consumes organic molecules and compounds other than O2 and yields ATP
-uses an electron transport chain with final electron acceptor other than O2
Transfer of electrons
-releases potential energy stored in organic molecules
-used to synthesize ATP
Oxidation reduction reactions
-transfer electrons between reactants
Oxidation
substance that loses electrons
-oxidized
Reduction
-substance gains electrons
-reduced
-amount of positive change reduced
Reducing agent
the electron donor
Oxidizing agent
the electron receptor
NAD+
-electron shuttle
-where electrons from organic compounds are first transferred
-is an oxidizing agent in cellular respiration
NADH
-reduced form of NAD+
-represents stored energy that is tapped to synthesize ATP
-passes electrons to electron transport chain
Electron transport chain
-passes electrons in a series of steps
-O2 pulls electrons down chain in energy yielding tumble
-energy yielded is used to regenerate ATP
-in the inner membrane (Cristae) of mitochondrion
-most of chains components are proteins and exist in multi protein complexes
-electrons drop in free energy as they go down chain
Stages of cellular respiration
- glycolysis
- pyruvate oxidation and citric acid cycle
- oxidation phosphorylation