Ch 7: Microbial Metabolism

What pertains to all chemical reactions and physical workings of the cell?

Metabolism

Which type of metabolism:

• A building and bond-making process that forms larger macromolecules from smaller ones.

• Requires the input of energy.

Anabolism

Which type of metabolism:

• Breaks the bonds of larger molecules into smaller molecules.

• Releases energy.

Catabolism

The breakdown of peptidoglycan to N-acetylmuramic acid, N-acetylglucosamine, and peptides is an example of __.

catabolism.

Formation of peptide bonds between amino acids to build a polypeptide would be called __.

anabolism.

Biological catalysts have the following characteristics EXCEPT:

All choices are characteristics.

Which enzyme structure:

__ - is a combination of a protein and one or more cofactor.

Holoenzyme

Which enzyme structure:

__ - protein portion of a holoenzyme.

Apoenzyme

Which enzyme structure:

__ - either organic molecules called coenzymes or inorganic elements (metal ions).

Cofactors

Coenzymes have the following characteristics EXCEPT:

All choices are characteristics.

Denaturation perform the following functions EXCEPT:

All choices are functions of Denaturation.

The cell’s metabolic reactions involve the participation of __ that lower the activation energy needed for the initiation of a reaction.

enzymes

Each of the following is true of enzymes except:

They increase the initial energy required for a reaction to start.

Important components of coenzymes are __.

vitamins.

Which type of direct control on action of Enzymes:

• Inhibits enzyme activity by supplying a molecule that resembles the enzyme’s normal substrate

• “Mimic” occupies the active site, preventing the actual substrate from binding

Competitive inhibition

Which type of direct control on action of Enzymes:

• Enzymes have two binding sites: the active site and a regulatory site

• Molecules bind to the regulatory site

• Slows down enzymatic activity once a certain concentration of product is reached

Noncompetitive inhibition

Which type of control on Enzyme synthesis:

__ - genetic apparatus responsible for replacing enzymes is automatically suppressed.

Enzyme repression

Which type of control on Enzyme synthesis:

__ - enzymes appear (are inducted) only when suitable substrates are present.

Enzyme induction

Energy is mostly stored as __.

ATP

Which energy reaction in cells:

__ - releases energy as it goes forward.

Exergonic reactions

Which energy reaction in cells:

__ - require the input of energy.

Endergonic reactions

Energy released during __ reactions is stored in __-energy phosphate bonds in ATP.

exergonic, high

ATP temporarily stores and releases the energy in these __ bonds to fuel __ reactions.

chemical, endergonic

What is loss of electrons, and when a compound loses electrons, it is oxidized? (giving off energy)

Oxidation

What is gain of electrons, and when a compound gains electrons, it is reduced? (high energy holding)

Reduction

Which redox reaction:

__ - enzymes that remove electrons from one substrate and add them to another.

Oxidoreductases

Which redox reaction:

__ - an electron donor and an electron acceptor involved in a redox reaction.

Redox pair

Energy now present in the electron acceptor can be captured to __ (add an inorganic phosphate) to ADP or to some other compound to store energy in __.

phosphorylate, ATP.

__ - always occur in pairs with one electron donor and one acceptor.

Redox rxns

The removal of the terminal phosphate __.

releases energy.

__ - removal of hydrogens from a compound during a redox reaction.

Dehydrogenation

In a redox reaction, loss of electrons is __.

oxidation.

Metabolism uses enzymes to __ (breakdown) organic molecules to precursor molecules that cells then use to __ (build) larger, more complex molecules.

catabolize, anabolize

__ - electrons available in NADH and FADH₂.

Reducing power

__ - stored in the bonds of ATP.

Energy

__ relies on free oxygen as the final electron and hydrogen acceptor.

Aerobic respiration

Fermentation have the following characteristics EXCEPT:

All choices are characteristics.

All three metabolic pathways begin with __, which turns glucose into two copies of __.

glycolysis, pyruvic acid.

__ is used by strictly anaerobic organisms and those who can metabolize with or without oxygen.

Anaerobic respiration

In the final step of Krebs cycle, __ accepts electrons and hydrogen, forming water.

oxygen

Aerobic respiration yields max of __ ’s per NADH and __ ’s per FADH2.

3 ATP, 2 ATP

None of the __ pathways produce as much ATP as __ respiration.

anaerobic, aerobic

After pyruvic acid, fermentation yields a __ amount of ATP.

small

Metabolic pathways that regenerate their starting point are called __ pathways.

cyclic

Products of Fermentation in Microorganisms

__ - ethanol and CO₂

Alcoholic beverages

Products of Fermentation in Microorganisms

__ - acetone, butanol

Solvents

Products of Fermentation in Microorganisms

__ - lactic acid, acetic acid

Organic acids

Large-scale industrial syntheses by microorganisms often utilize entirely different fermentation mechanisms for the production of …

… antibiotics, hormones, vitamins, and amino acids.

Most electron carriers are __.

coenzymes.

Exergonic reactions __.

release energy.

In the cell, energy released by electrons is often used to phosphorylate __.

ADP.

FAD, NAD, and coenzyme A are all __ carriers.

hydrogen / electron

Glycolysis

uses 2 ATPs, produces 4 ATP, without using oxygen.

In bacterial cells, the electron transport system is located in the __.

cell membrane.

The redox carriers of the electron transport chain that have a tightly bound metal atom responsible for accepting and donating electrons are __.

the cytochromes.

NADH and FADH₂ molecules are oxidized in which step of the aerobic respiration process?

electron transport system

When glucose is broken down by glycolysis during bacterial fermentation, how many ATP are generated?

2 ATP