Cellular Respiration Chapter 9
Food = source of energy
A Calorie – is the amount of energy needed to raise the temperature of 1 gram of water 1 degree Celsius.
Cells don’t “burn” glucose or other foods. Instead, they gradually release the energy.
The Calorie used on food labels is a kilocalorie, or 1000 calories
Feel the BurnDo you like to run, bike, or swim? These all are good
ways to exercise. When you exercise, your body uses oxygen to get energy from glucose,a six-carbon sugar.
1.How does your body feel at the start of exercise, such as a long, slow run? How do you feel 1 minute into the run; 10 minutes into the run?2.What do you think is happening in your cells to cause the changes in how you feel?3.Think about running as fast as you can for 100 meters. Could you keep up this pace for a much longer distance? Explain your answer.
Cellular Respiration
The process that releases energy by breaking down glucose & other food molecules in the presence of oxygen.
6O2 + C6H12O6 → 6CO2 + 6H2O + Energy
oxygen + glucose → carbon dioxide + water + energy
Glucose
Glycolysis Krebs cycle
Electrontransport
Fermentation (without oxygen)
Alcohol or lactic acid
Chemical PathwaysSection 9-1
GlucoseGlycolysis
Cytoplasm
Pyruvic acid
Electrons carried in NADH
Krebs Cycle
Electrons carried in
NADH and FADH2 Electron
Transport Chain
Mitochondrion
Figure 9–2 Cellular Respiration: An Overview
Mitochondrion
Section 9-1
3 Stages make up Cellular Respiration
Glycolysis – process in which 1 molecule of glucose is broken in half, producing 2 molecules of pyruvic acid & gains 2 ATP molecules. O2 present - it is followed by the Kreb Cycle & the
electron transport chain. O2 not present (anaerobic) - it is followed by
fermentation.
Glycolysishttp://highered.mcgraw-hill.com/sites/0072507470/student_view0/chapter25/animation__how_glycolysis_works.html
Fermentation
Fermentation – releases energy in food & converts NADH back into NAD+ keeping the supply of ATP constant.
Alcoholic fermentation – yeasts & a few other microorganisms; causes bread dough to rise.
Lactic Acid fermentation – in muscles during rapid exercise when the body can’t supply enough O2 to the tissues; without oxygen, the body isn’t able to produce the ATP required. Buildup causes pain & soreness.
Rolling and Folding
Some of the steps in cellular respiration take place in the membrane inside the cell structure called the mitochondrion, which has a folded inner membrane. What purpose do these folds serve?
Section 9-2
FlowchartSection 9-2
Glucose(C6H1206)
+Oxygen
(02)
GlycolysisKrebsCycle
ElectronTransport
Chain
Carbon Dioxide
(CO2)+
Water(H2O)
Cellular Respiration
3 Stages make up Cellular Respiration
Kreb Cycle – requires O2 (aerobic) In eukaryotes. Takes place in the mitochondria. Aka. Citric acid cycle b/c it’s one of the first products. Pyruvic acid is broken down into CO2 which is
released into the air. NAD+ is changed to NADH & FAD is changed to
FADH2 which carry high-energy electrons to the electron transport chain.
The Krebs Cyclehttp://highered.mcgraw-hill.com/sites/0072507470/student_view0/chapter25/animation__how_the_krebs_cycle_works__quiz_1_.html
3 Stages make up Cellular Respiration
Electron Transport – uses high-energy electrons from the Krebs cycle to convert ADP into ATP. In eukaryotes it’s composed of carrier proteins located in the
mitochondria. In prokaryotes the same chain is in the cell membrane where
energy is used to move H+ ions through ATP synthase. ATP synthase – protein sphere that spins, adding a phosphate
to ADP creating ATP.
Figure 9–7 Electron Transport Chain
Electron TransportHydrogen Ion Movement
ATP Production
ATP synthase
Channel
Inner Membrane
Matrix
Intermembrane Space
Mitochondrion
The Human Body
Contains small amounts of ATP. When the body needs energy fast, muscle
cells produce ATP by Lactic Acid Fermentation.
For long-term needs, the body must use cellular respiration.
Comparing Photosynthesis & Cellular Respiration Energy flows in Photosynthesis Cellular Respiration takes place in the
opposite direction.Photosynthesis – removes CO2 & puts O2
back into air.Cellular Respiration – removes O2 & puts CO2
back into air.