Chapter 6: Microbial Metabolism: Fueling Cell Growth

The three central metabolic pathways that gradually oxidize glucose to CO2 are _______, the ___________ _____________ pathway, and the __________ cycle

Glycolysis Pentose phosphate pathway tricarboxylic acid cycle (TCA cycle)

Hydrogen sulfide is produced as a result of certain types of anaerobic respiration. Some chemolithotrophs can then use this as a/an ______________

energy source

the sum total of chemical reactions in a cell

metabolism

A cell will usually contain about how many different enzymes? six one about 50 10 fewer than 100 more than 1000

more than 1000

____________, ___________, and ___________ can (or have some groups that can) harvest the radiant energy of sunlight and then use it to power the synthesis of organic compounds from CO2 in a process called photosynthesis

plants, algae, and bacteria

Cellular respiration uses the ___________ ______________ generated in glycolysis, the transition step, and the TCA cycle to synthesize ATP

reducing power

What occurs during the transition step of central metabolism? -Two 3-carbon pyruvate molecules are joined to form a 6-carbon citrate -2 ATP are generated -Electrons are transferred to NAD+, reducing it to NADH + H+ -CO2 is removed from pyruvate -The 2-carbon acetyl group is joined to coenzyme A to form acetyl-CoA -CO2 is combined with pyruvate to form the 4-carbon molecule succinat

-Electrons are transferred to NAD+, reducing it to NADH + H+ -CO2 is removed from pyruvate -The 2-carbon acetyl group is joined to coenzyme A to form acetyl-CoA

Which of the following correctly describe respiration? -All organisms that grow in the presence of O2 must use respiration for their energy needs -Electrons extracted from glucose are transferred to the electron transport chain -The electron transport chain uses the electrons to generation a proton motive force that can be used to generate ATP -it is only present in aerobic organisms

-Electrons extracted from glucose are transferred to the electron transport chain -The electron transport chain uses the electrons to generation a proton motive force that can be used to generate ATP

What is the active site of an enzyme? -the site characterized by constant motion of molecules -the site of allosteric regulation of the enzyme -the critical site to which a substrate binds by weak forces -the site at which ATP is generated -the site that breaks off the enzyme as it catalyzes a reaction

-the critical site to which a substrate binds by weak forces

Rank the following energy-generation processes from greatest yield to least energy yield. fermentation aerobic respiration anaerobic respiration

aerobic respiration anaerobic respiration fermentation

the set of chemical reactions that synthesize and assemble the subunits of macromolecules

anabolism

the set of chemical that degrade compounds releasing their energy

catabolism

Glucose catabolism encompasses two key processes: (1) oxidizing glucose molecules to generate ATP, reducing power, and precursor metabolites; and (2) tranferring the electrons carried by NADH and FADH2 to the terminal electron acceptor. The second process, transfer of electrons, is accomplished by which of the following? -fermentation -glycolysis -the TCA cycle -the pentose phosphate pathway -respiration

fermentation respiration

the primary pathway used to many organisms to convert glucose to pyruvate is ____________

glycolysis