cellular respiration chapter 9. interest grabber feel the burn do you like to run, bike, or swim?...
TRANSCRIPT
Cellular Respiration
Chapter 9
Interest Grabber
• Feel the Burn
• Do 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.
Section 9-1
1. How does your body feel at the start of exercise, such as a long, slowrun? 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 changesin how you feel?
3. Think about running as fast as you can for 100 meters. Could youkeep up this pace for a much longer distance? Explain your answer.
Sunlight powers life• Autotrophs
– Photosynthesis– Producers
• Heterotrophs– Consumers
• Cellular respiration- converts energy into cell fuel (ATP
Why do living things need food?
• provides living things with the chemical building blocks they need to grow and reproduce.
• Source of raw materials for making new molecules
• source of energy
What do cells do with food?
• Cells gradually release energy from glucose and other food compounds in the form of ATP.
ATP
• Most of the energy from cell respiration is converted into ATP
• ATP is a substance that powers most cell activities.
• Energy in phosphate bonds
Cellular Respiration
• Process that releases energy by breaking down glucose to make ATP at each stage
• 3 Steps– Glycolysis– Kreb’s cycle– Electron Transport
Chain
Formula
Cellular Respiration3 stages:
1. Glycolysis –the breaking of glucose into pyruvate
2. Kreb’s Cycle–pathway which converts pyruvate
3. Electron Transport Chain- coverts NADH into ATP
The 3 steps of cellular respiration
1. Glycolysis2. Kreb’s cycle3. Electron Transport
Chain
• Each stage captures some of the chemical energy available in food molecules and uses it to produce ATP.
Glucose
Glycolysis Krebs cycle
Electrontransport
Fermentation (without oxygen)
Alcohol or lactic acid
Chemical Pathways
Section 9-1
Glycolysis
• Occurs in cytoplasm
• Does not require oxygen
• Net gain of ATP = 2• Molecule of
glucose is broken in half to two pyruvate molecules
(then goes into mitochondria)
Cellular Respiration
End of Glycolysis
• 90% of the energy of glucose still has not been used
• The energy is stored in the electrons of pyruvic acid
Cellular RespirationStage Two(Aerobic): Production of ATP
•Krebs Cycle • reactions that produce
energy-storing molecules (NADH and ATP)
• Pyruvate citric acid• In mitochondria• Carbon dioxide given
off
Citric Acid Production
Figure 9–6 The Krebs Cycle
Section 9-2
Mitochondrion
Mitochondria• The matrix where 3-
carbon pieces that came from carbohydrates are broken down to (CO2 and water)
• The cristae is where ATP is made
Stage 3- ETC- Electron transport chain
• Hot potato-electrons• Uses high energy electron to convert
NADH in to ATP• Oxygen gets the “hot potato” to
make water
Figure 9–7 Electron Transport Chain
Section 9-2
Electron TransportHydrogen Ion Movement
ATP Production
ATP synthase
Channel
Inner Membrane
Matrix
Intermembrane Space
Mitochondrion
Fermentation(anaerobic)
• When oxygen is not present, gylcolysis follows this pathway (anaerobic)
• Two types– Alcoholic
fermentation– Lactic Acid
Fermentation
Alcoholic Fermentation
• Yeasts and other microorganisms
• Causes bread to rise• Formula
Lactic Acid Fermentation
• Pyruvic acid can turn to lactic acid so gylcolysis can continue
• Produced in muscles during exercise when oxygen is used up
• Muscles continue to make ATP
Alcohol Fermentation
• Unicellular organisms also go through this process
• Used in the productions of foods and beverages-cheese, yogurt, sour cream, pickles, alcoholic beverages
Summary
Molecule Role in respiration
C6 H12O6 Broken down in glycolysis = 2 ATP made, pyruvate
O2 Accepts H+ in ETC, aids in making ATP * Aerobic respiration only
H2O Made in ETC, waste product
CO2 Made in Krebs cycle, waste product
Flowchart
Section 9-2
Glucose(C6H1206)
+Oxygen
(02)
Glycolysis KrebsCycle
ElectronTransport
Chain
Carbon Dioxide
(CO2)+
Water(H2O)
Cellular Respiration
Review