Energy production and catabolism

TABLE 13.1

• ATP contains a base, sugar, and three phosphates.• Under physiological conditions, ATP always forms a

complex with Mg2+.

Adenosine Triphosphate

Figure 13.6

Figure 13.7A

• Flavine adenine dinucleotide (FAD) is another related coenzyme that can transfer electrons.

• - FADH2: reduced form

• - FAD: oxidized form

• Unlike NAD+, FAD is reduced by two electrons and two protons.

FADH

Figure 13.7B

• Enzymes couple specific energy-yielding reactions with energy-requiring reactions.

Enzymes

Figure 13.9

• Microbes catalyze many different kinds of substrates or catabolites.

Figure 13.11

Figure 13.13

• Glucose is catabolized via three main routes.

Glucose Breakdown

Figure 13.15

• In the EMP pathway, a glucose molecule undergoes a stepwise breakdown to two pyruvate molecules.

Embden-Meyerhoff-Parnas Pathway

Figure 13.16

Figure 13.17

Figure 13.19

Figure 13.20

Figure 13.21

Figure 13.24

Conversion of pyruvate to acetyl-CoA is catalyzed by a very large multisubunit enzyme called the pyruvate dehydrogenase complex (PDC).- The net reaction is:

Pyruvate + NAD+ + CoA → Acetyl-CoA + CO2 + NADH + H+

Figure 13.25A

Figure 13.27

Figure 13.28

Aromatic CatabolismIn anaerobic conditions, benzoate undergoes

reductive degradation instead of oxidation.- Benzoate is first activated by acetyl-CoA, then it is reduced by NADPH.

Figure 13.30A