Chapter 9: Cellular Respiration. Objectives The student is responsible for: The definitions of all bold faced words in the chapter Knowing the entire chapter. The student is not responsible for: Memorizing or drawing the structures of glycolysis or Kreb’s cycle.
Fermentation: decomposition of glucose without the use of oxygen
Cellular Respiration: oxygen is a reactant when glucose is broken down
The production of ATP is an exergonic process
ATP -> ADP + Pi
ADP AMP + Pi
Why do we care so much about ATP? respiration.Figure 9.2 A review of how ATP drives cellular work
Oxidizing Agent: that substance that is being reduced.
O is “going” from O (no charge) to O2-.
Reducing Agent: that substance that is being oxidized.
C is gaining oxygen.
The molecule that is used to move hydrogen ions throughout the oxidation of food is NAD+. Therefore NAD+ is an oxidizing agent.Figure 9.4 NAD+ as an electron shuttle
NAD+ + H+ NADH
But if we could get this pyruvate into the mitochondria we could make a whole lot more ATP!!
What is this substrate-level phosphorylation?
This is when a phosphate group is moved from an organic compound to ADP.
What is oxidative phosphorylation?
When electrons and H+ are used to make ATP.
Couldn’t these NADH’s that are made be used to make ATP?
Could the NADH produced here be used to make ATP?
Keep track of the number of carbons!!
NADH and FADH junction between glycolysis and the Krebs cycle2 deliver electrons to different locations in the ETC.Figure 9.13 Free-energy change during electron transport
The role of oxygen is to serve as a hydrogen ion acceptor to form water.
ATP Synthase junction between glycolysis and the Krebs cycle
Chemiosmosis: the coupling of the movement of H+ through a protein complex (ATP Synthase) making ATP.Figure 9.14 ATP synthase, a molecular mill
A Proton-Motive Force is produced
Power Bars? many ATP molecules during cellular respiration
Goo?Figure 9.19 The catabolism of various food molecules
Versatility of Catabolism many ATP molecules during cellular respiration
The Evolutionary Significance of Glycolysis many ATP molecules during cellular respiration
Earliest organisms were in an anaerobic environment (3.5 billion yrs ago)
Glycolysis was probably used as an energy making process
Oxygen accumulated about 2.7 billion years ago
Glycolysis is the most widespread pathway amongst organisms suggesting it evolved early on.
Glycolysis requires only the cytoplasm and membrane-bound organelles were not present until eukaryotic cells appeared (2 billion years after prokaryotes)