Ch 7
暂无描述。系统推荐的高质量记忆内容，适合每天坚持背诵学习。
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Autotrophs
Capture energy and build organic molecules through photosynthesis
Heterotrophs
Use pre-formed organic molecules for both energy and to build new organic molecules
What is it that all organisms use to extract energy from organic molecules?
Cellular respiration
What types of reactions are involved in cellular respiration?
Redox and dehydrogenations
Dehydrogenation
Electron transfers accompanied by proton transfers
What type of atom is transferred in cellular respiration?
Hydrogen
NAD+ has a positive charge, so…
It attracts an electron, which makes it an electron carrier But then it attracts a proton, which leads to a proton gradient (I think)
How does NAD+ become NADH
It accepts 2 electrons and 1 proton
The “goal” of respiration is
To generate ATP
What’s the movement of electrons during respiration?
They’re shuttled via electron carriers (transport chains) to a final electron acceptor
Aerobic respiration
Final acceptor is oxygen
Anaerobic respiration
Final acceptor is an inorganic molecule (but not oxygen)
Fermentation
Final acceptor is an organic molecule
Proton gradient (which he said was important but didn’t bother to define in the slides)
A higher concentration of protons outside the inner membrane of the mitochondria than inside the membrane The driving force behind ATP synthesis Product of the electron transport chain
Chemical formula for aerobic respiration
C6 H12 O6 + 6O2 –> 6CO2 + 6H2O
Where does aerobic respiration occur?
Mitochondrial matrix
What’s the first step of aerobic respiration and how many ATP are produced?
Glycolysis 4 ATP are produced but we used 2 ATP in the process so there’s a net gain of 2 ATP
What is the second step of aerobic respiration and what is produced?
1 ATP molecule and 3 molecules of CO2 Most importantly it yields several molecules of NADH and FADH2
Why is the Krebs cycle repeated
Bc only 1 pyruvate is needed for the cycle and 2 were produced during glycolysis This means you get 6 CO2 and 2 ATP from this step total
What is the third step of aerobic cellular respiration? What is produced?
Electron transport chain 32-34 ATP
Three reactants and three products of glycosis?
R: one glucose, NAD+, 2 ATP P: 2 pyruvate, NADH, 4 ATP
Three reactants and products of the electron transport chain?
R: NADH, FADH2, O2 P: 1 NAD+, H2O, 32-34 ATP
Two steps to anaerobic respiration?
Glycolysis and fermentation
Fermentation (in anaerobic respiration)
Starts with private and ferments it into ethanol or lactate. Releases CO2 only (no ATP)