CHAPTER 7: CELLULAR RESPIRATION
CELLULAR RESPIRATION•Process where cells make ATP by breaking down glucose
CELLULAR RESPIRATION
•Process where cells make ATP by breaking down glucose
•Autotrophs and heterotrophs both undergo respiration
• Occurs in the cytoplasm and mitochondria
CELLULAR RESPIRATION
Overall equation:
C6H12O6 + 6O2 6CO2 + 6 H2O + ATP
How is this equation different from photosynthesis?
WHAT’S SO GREAT ABOUT ATP?
Every time you move a muscle, think, breathe, replicate your DNA, every time your heart beats - you use ATP to do this work!
TWO PATHWAYS EXIST FOR ACCESSING STORED ENERGY…
Aerobic Pathways take place in the presence of oxygen
TWO PATHWAYS EXIST FOR ACCESSING STORED ENERGY…
Aerobic Pathways take place in the presence of oxygen
Anaerobic Pathways take place in the absence of oxygen
Both pathways: 1) Begin with Glycolysis 2) Produce a Pyruvic Acid Intermediate 3) Differ in ATP production and final product
TWO PATHWAYS EXIST FOR ACCESSING STORED ENERGY…
Aerobic Pathways take place in the presence of oxygen
Anaerobic Pathways take place in the absence of oxygen
STEPS OF CELLULAR RESPIRATION
STEP 1: GLYCOLYSIS 6-carbon glucose molecule is broken down into two 3-carbon pyruvic acid molecules.
STEP 1: GLYCOLYSIS 6-carbon glucose molecule is broken down into two 3-carbon pyruvic acid molecules.Location: cytoplasmReactant: glucoseProducts: pyruvic acid and 2 ATPsAnaerobic: does not require oxygen
If oxygen is present then Aerobic respiration occurs
If oxygen is not available then cells continue to perform glycolysis to make 2 ATPs
MITOCHONDRIA PARTS Matrix: Fluid
Inner membrane: folded membrane inside mitochondria
Cristae: inner folds of innermembrane
Intermembrane space: space between outer and innermembrane
Krebs Cycle: • Series of reactions that
occur in mitochondrial matrix
STEP 2: KREB’S CYCLE
Krebs Cycle: • Series of reactions that
occur in mitochondrial matrix
Reactants: • Pyruvic acid (from glycolysis)
STEP 2: KREB’S CYCLE
Krebs Cycle: • Series of reactions that
occur in mitochondrial matrix
Reactants: • Pyruvic acid (from glycolysis)
Products: • 2 CO2 • 2 ATP• NADH (e- carrier)
STEP 2: KREB’S CYCLE
• The “big ATP payoff” • Location: cristae (inner membrane) of mitochondria• Reactants: NADH, O2
• Products: NAD+, H2O, 34 ATP
STEP 3: ELECTRON TRANSPORT CHAIN AND CHEMIOSMOSIS
•NADH transfers e- to the Electron transport chain
(e- move down a series of proteins)
Figure 4.22
•NADH transfers e- to the Electron transport chain
(e- move down a series of proteins)
•At the end of the chain, the electrons combine with oxygen & H+ to produce H2O.
Figure 4.22
STEP 3: ELECTRON TRANSPORT CHAIN AND CHEMIOSMOSIS Energy from the e- pulls H+ into the intermembrane space.
Figure 4.22
STEP 3: ELECTRON TRANSPORT CHAIN AND CHEMIOSMOSIS•H+ move from HIGH conc. to LOW conc.
Outer mitochondrialmembrane
Innermitochondrialmembrane
Electron transportchain proteins
NADH 26
1/2 O2 + 2H+ H2O
H+
H+ H+
H+
Cytosol
Intermembranespace
2 2
ADP + P
ATP
STEP 3: ELECTRON TRANSPORT CHAIN AND CHEMIOSMOSIS•H+ move from HIGH conc. to LOW conc.
•They diffuse through ATP synthase, generating 34 ATPs (chemiosmosis)
Outer mitochondrialmembrane
Innermitochondrialmembrane
Electron transportchain proteins
NADH 26
1/2 O2 + 2H+ H2O
H+
H+ H+
H+
Cytosol
Intermembranespace
2 2
ADP + P
ATP
2 ATP from glycolysis2 ATP from Kreb’s Cycle
2 ATP from glycolysis2 ATP from Kreb’s Cycle
34 ATP from ETC (chemiosmosis)
2 ATP from glycolysis2 ATP from Kreb’s Cycle
34 ATP from ETC (chemiosmosis)
38 ATP Made In Total
2 ATP from glycolysis2 ATP from Kreb’s Cycle
34 ATP from ETC (chemiosmosis)
38 ATP Made In Total
- 2 ATP for transporting pyruvic acid into the Mitochondria from Glycolysis
2 ATP from glycolysis2 ATP from Kreb’s Cycle
34 ATP from ETC (chemiosmosis)
38 ATP Made In Total
- 2 ATP for transporting pyruvic acid into the Mitochondria from Glycolysis
36 Net ATP Made
Aerobic Respiration is 20 times more efficient than Glycolysis alone.
ANAEROBIC VS. AEROBIC Anaerobic pathway (fermentation): Glycolysis 2 ATP
ANAEROBIC VS. AEROBIC Anaerobic pathway (fermentation): Glycolysis 2 ATP
Aerobic Pathway: Glycolysis + Kreb’s Cycle + ETC 36 ATP
MAKE AND FILL IN THIS CHART
Process Location
Reactants
Products
# of ATP Made
Glycolysis
Kreb’s Cycle
Electron Transport Chain
MOVIES: 342101, 342201 & 342301
Fact: Our bodies uses ATP at the rate of about 1 million molecules per cell per second.
There are more than 100 trillion cells in the human body. That’s about 100,000,000,000,000,000,000 ATP molecules used in your body each second!
What is the relationship between autotrophs and heterotrophs?
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