Energy Generation:
● Energy flows into an ecosystem as sunlight and leaves as heat.
● Essential chemical elements are recycled
● Photosynthesis generates O2 and organic molecules which are used in cellular
respiration
● Cells use chemical energy stored in organic molecules to generate ATP (energy)
● Catabolism fuels anabolism
Cellular Respiration:
● Carbohydrates, fats, and proteins are consumed as fuel
● Reaction: C6H12O6 + 6 O2 -> 6 CO2 + 6 H2O + Energy(ATP + heat)
Redox Reactions:
● Oxidation: substance LOSES electrons (is oxidized)
○ LEO - Loses Electron Oxidized
● Reduction: substance GAIN electrons (is reduced)
○ GER - Gain Electron Reduction
● The transfer of electrons during chemical reactions releases energy stored in organic
molecules.
Energy Harvest via NAD+ and Electron Transport Chain
● Electrons transferred to NAD+, a coenzyme
● As an electron acceptor, NAD+ functions as an oxidizing agent during cellular respiration
● Each NADH (the reduced form of NAD+) represents stored energy that is tapped to
synthesize ATP
● NADH passes the electrons to the electron transport chain
● O2 pulls electrons down the chain in an energy-yielding tumble
● The energy yielded is used to regenerate ATP
Stages of Cellular Respiration
● 1 - Glycolysis (breaks down glucose into two molecules of pyruvate)
● 2 - Pyruvate Oxidation and the Citric Acid Cycle (completes the breakdown of glucose)
● 3 - Oxidative Phosphorylation: Electron transport and chemiosmosis (accounts for most
of the ATP synthesis)
1 - Glycolysis
● Breaks down glucose into two molecules of pyruvate (3 carbon)
● Glycolysis occurs in the cytoplasm and has two major phases
○ Energy investment phase
○ Energy payoff phase
● Glycolysis occurs whether or not O2 is present
● All living organisms have the core of glycolysis and it is in the cytoplasm (not an
organelle) - suggesting the first living cells did a form of glycolysis
● The process that generates almost 90% of the ATP is called oxidative phosphorylation
because it is powered by redox reactions
● Energy flows into an ecosystem as sunlight and leaves as heat.
● Essential chemical elements are recycled
● Photosynthesis generates O2 and organic molecules which are used in cellular
respiration
● Cells use chemical energy stored in organic molecules to generate ATP (energy)
● Catabolism fuels anabolism
Cellular Respiration:
● Carbohydrates, fats, and proteins are consumed as fuel
● Reaction: C6H12O6 + 6 O2 -> 6 CO2 + 6 H2O + Energy(ATP + heat)
Redox Reactions:
● Oxidation: substance LOSES electrons (is oxidized)
○ LEO - Loses Electron Oxidized
● Reduction: substance GAIN electrons (is reduced)
○ GER - Gain Electron Reduction
● The transfer of electrons during chemical reactions releases energy stored in organic
molecules.
Energy Harvest via NAD+ and Electron Transport Chain
● Electrons transferred to NAD+, a coenzyme
● As an electron acceptor, NAD+ functions as an oxidizing agent during cellular respiration
● Each NADH (the reduced form of NAD+) represents stored energy that is tapped to
synthesize ATP
● NADH passes the electrons to the electron transport chain
● O2 pulls electrons down the chain in an energy-yielding tumble
● The energy yielded is used to regenerate ATP
Stages of Cellular Respiration
● 1 - Glycolysis (breaks down glucose into two molecules of pyruvate)
● 2 - Pyruvate Oxidation and the Citric Acid Cycle (completes the breakdown of glucose)
● 3 - Oxidative Phosphorylation: Electron transport and chemiosmosis (accounts for most
of the ATP synthesis)
1 - Glycolysis
● Breaks down glucose into two molecules of pyruvate (3 carbon)
● Glycolysis occurs in the cytoplasm and has two major phases
○ Energy investment phase
○ Energy payoff phase
● Glycolysis occurs whether or not O2 is present
● All living organisms have the core of glycolysis and it is in the cytoplasm (not an
organelle) - suggesting the first living cells did a form of glycolysis
● The process that generates almost 90% of the ATP is called oxidative phosphorylation
because it is powered by redox reactions
