7.1/7.2Importance of Cellular Respiration &
GlycolysisCellular Respiration1Complementary
ReactionsPhotosynthesis: series of reactions that convert light
into chemical energy to produce energy-rich glucose
molecules.Glucose can be used immediately or stored.Cellular
Respiration: series of reactions that release the energy stored in
glucose (in the form of ATP)CO2(g) + H2O(l) + energy C6H12O6(s) +
O2(g)C6H12O6(s) + O2(g) CO2(g) + H2O(l) + energy2Compare and
Contrast
3IntermediatesOxidation-reduction (redox) reactions produce
intermediate products used by cells to complete processesLEO the
lion goes GERPhotosynthesis: NADPH (reduced from of NADP+) and
ATPCellular Respiration: NADH (reduced form of NAD+) and FADH2
(reduced form of FAD+)Serve as electron carriers: transfer
electrons through redox reactionsEnergy released can be used to
make ATP (attach ADP to Pi)4Cellular RespirationBreaking down of
large energy molecules of glucose into smaller moleculesThe smaller
you break them down, the more energy you can derive from the
processThe energy released in cellular respiration is used to
synthesize ATPGlucose molecules must be converted into another form
of energy (ATP) before it is useful to the body
5ATPEstimated 1 billion molecules of ATP in a human cell-
continuously broken down into ADP and Pi and reformedMost processes
that require ATP energy can be placed into one of the following
categories (Table 1 pg 206)- motion- transport of ions/molecules-
building of molecules- switching reactions on and off-
bioluminescence
6Glucose Our blood sugar: high energy content, small, highly
soluble- ideal for transportationChemical bonds of reactant food
molecules (glucose) broken during respirationBreak bonds = requires
energyNew bonds = energy releasedRespiration an energy-releasing
process: more energy released during formation of product
moleculesSingle glucose molecule- 36% converted into energy of ATP-
64% released as heat7Types of Cellular RespirationAerobic cellular
respiration: requires O2 and involves complete oxidation of glucose
(produces 36 ATP)- Stage 1: glycolysis (cytoplasm)- Stage 2:
pyruvate oxidation (mitochondria)- Stage 3: Krebs Cycle
(mitochondria)- Stage 4: ETC and chemiosmosis (inner
mitochondria)Anaerobic cellular respiration: occurs in absence of
O2 and glucose is not completely oxidized.- Stage 1: glycolysis
(cytoplasm)- Stage 2: fermentation (cytoplasm)2 types of anaerobic
respiration: one produces ethanol, one produces lactic acidNOTE:
BOTH BEGIN WITH GLYCOLYSIS!!!
8
9Aerobic cellular respiration: Overview
10Stage 1: Glycolysissugar splittingNo oxygen requiredThus it is
the first step for both aerobic and anaerobic respirationOccurs in
the cytoplasmStarts with glucose (6-carbon sugar)2 ATP molecules
are used in the first stages of glycolysis (investment phase)2 NAD+
removes H+ ions and forms 2 NADHLater enough energy is released to
form 4 ATP, which will be available to be used in cellular
functionsGlycolysis produces TWO 3-carbon pyruvate moleculesNet
production of 2 ATP11Glycolysis
12GlycolysisRelatively inefficientOnly transfers about 2.2% of
free energy available in glucose to ATPSome released as heat, but
remainder tied up in pyruvate and 2 NADH moleculesglycolysis
