CHP-6 Microbial Metabolism

In addition to yielding energy, catabolic pathways generate carbon intermediates that can be used in anabolic pathways for the biosynthesis of macromolecules. These carbon skeletons are called

precursor metabolites

The form of energy that results from the electrochemical gradient established by the electron transport chain is the

proton motive force

The three main types of electron carriers in a typical electron transport chain are

quinones, cytochromes, and flavorproteins

Certain intermediates of catabolic pathways, called precursor metabolites, are important because ______.

they serve as carbon skeletons from which subunits of macromolecules can be made

Until the optimal temperature is reached, raising the temperature has what effect on the speed of enzymatic reactions?

It increases their rate.

Which of the following are reasons an organism might use fermentation?

They lack an electron transport chain A suitable inorganic terminal electron acceptor is not available

The critical site of an enzyme to which a substrate binds by weak forces is called the

active site

Enzymes are biological __________ that are typically __________.

catalysts and protein

Proteins that function as biological catalysts are called

enzymes

Fats, the most common simple lipids, are broken down by lipases into their component

glycerol and fatty acids

Atoms that are more electronegative than others

have a higher affinity for electrons

Purines and pyrimidines are synthesized

in distinctively different manners

What are the two main forms of energy?

kinetic and potential

An atom that has a lower affinity for electrons than another is described as than the other.

less electronegative

The series of sequential chemical reactions in a cell that converts a starting compound to an end product is called a

metabolic pathway

When a cell processes glucose or other organic molecules through its central metabolic pathways, it does so to generate what three critical things?

ATP, reducing power, precursor metabolites

Non-competitive inhibition by regulatory molecules

Allosteric regulators

In addition to glucose, which of the following organic compounds can serve as energy sources for microbes?

Disaccharides, polysaccharides, lipids, fatty acids, monosaccharides, proteins

Which of the following correctly describe cytochromes found in an electron transport chain?

Several different cytochromes exist.

Competitive inhibition

Sulfa drugs

The sum total of all chemical reactions in a cell is called

metabolism