1. Alternative Pathways in cell respiration

2. Cell Respiration is separated into 3 stages
ELECTRON TRANSPORT AND OXIDATIVE PHOSPHORYLATION
GLYCOLYSIS
KREBS CYCLE
NADH
FADH2
NADH
NADH
Electron transport chain...
Glucose
Pyruvate
Krebs
Cycle
CO2
H2O
Figure: 6.3
Caption:
Cellular respiration consists of three component processes: glycolysis, the Krebs cycle, and electron transport combined with oxidative phosphorylation. Each component produces at least some ATP. Because the three components are connected, cellular respiration is an integrated metabolic pathway. Glycolysis and the Krebs cycle are connected by pyruvate; glycolysis and the Krebs cycle are connected to electron transport chains by NADH and FADH2.
CO2
ATP
ATP
ATP
Energy/electrons are transferred from glucose to convert NAD+ to NADH, which is used in the ETC to make ATP

3. I eat more than just glucose, what happens to all that stuff?
Vs.

4. The metabolism of all macromolecules is tied to cellular respiration
Carbohydrates, fats, and proteins can be broken down and used in glycolysis and the Kreb’s cycle.
Fatty acids
Glycerol
Amino acids
NH3
Fats
Carbs
Proteins
Sugars
Glucose
Pyruvate
Acetyl CoA
Krebs cycle

5. Cellular respiration is carefully regulated: when ATP is abundant, respiration slows down when ATP is needed, respiration speeds up
Figure: 6.7a
Caption:
(a) The oxidation of pyruvate and formation of acetyl CoA is under both negative and positive control. 

6. The metabolism of all macromolecules is tied to cellular respiration
Excess intermediates of glycolysis and the Kreb’s cycle can be converted to stored carbohydrates, fats and proteins.
Pathway for
synthesis of
RNA, DNA
Fats
Phospholipids
Glycogen
or starch
Fatty acids
Several intermediaries used as
substrates in amino acid synthesis
Pruvate
Glucose
Acetyl CoA
Krebs
cycle
Lactate
(from fermentation)

7. I eat only fat-free foods- Why am I still getting fat?
Figure: 6.18
Caption:
Several of the intermediates in carbohydrate metabolism act as precursor molecules in the synthesis of RNA, DNA, glycogen or starch, amino acids, and fatty acids.