Microbiology Exam 2

Phenolic compounds are effective against

Most vegetative bacteria, found in detergents, Lysol, work in the presence of organic material, and mycobacterium species

Three main structures targeted by chemicals

Nucleic Acids, Membrane proteins, cytoplasmic membrane

The genus Bdellovibrio

prey on gram negative bacteria by becoming an intracellular parasite

Ethylene oxide is a germicide that kills by reacting with

proteins

Mycoplasmas are

resistant to penicillin. susceptible to lysis by osmotic shock. lacking peptidoglycan

Production of ATP using the energy liberated when electrons from reduced chemical bonds are pass through the electron transport system is generally referred to as

respiration

Endospore-forming gram-positive bacteria are found primarily in __________ habitats.

soil

Competitive inhibition can be overcome by adding excess

substrate

The synthesis of ATP from ADP and Pi, when coupled with an exergonic chemical reaction is called __________ phosphorylation.

substrate-level

Which of the following groups of photosynthetic bacteria are capable of oxygenic photosynthesis?

the cyanobacteria

free energy

the energy released when a chemical bond is broken

Photoautotrophs use light energy directly for

the production of ATP and NADPH.

Cyanobacteria are procaryotes that carry out oxygenic photosynthesis like green plants; this means that

they use water as their electron source. they produce oxygen as a by-product of photosynthesis. they have two distinct photosystems.

EPA regulates chemicals used as

pesticides

A component an organic molecule can be called

Coenzyme

Some enzymes act with the assistance of a nonprotein component known as a

Cofactor

Which of the following is extremely radiation resistant?

Deinococcus

An atom that has a lower affinity(attraction) for electrons than another is described as ______ than another

Less Electronegative

An chemical reaction that requires an input of energy in order to proceed is __________.

endergonic

The major function(s) of the TCA cycle is(are)

energy production and provision of carbon skeletons for biosynthesis of cell components.

The two most important alcohol germicides are __________ and __________.

ethanol; isopropanol

A reaction that releases energy is __________.

exergonic

An agent that specifically kills fungi but not other kinds of microorganisms is also known as a

fungicide

Members of the genus Neisseria cause which of the following human diseases?

gonorrhea

Which of the following are photosynthetic bacteria?

green, blue purple

Members of the genus Rhizobium

grow symbiotically in root nodules of legumes where they fix nitrogen.

Large spherical cells of cyanobacteria that are able to fix atmospheric nitrogen are referred to as

heterocysts

may be used as sources of energy by chemolithotrophs?

hydrogen gas ammonia hydrogen sulfide

Hydrogen peroxide is an effective germicide because

it leaves no residue. it does not damage stainless steel, rubber or glass. it can be used on living tissue.

In aerobic conditions, it takes __________ sugar to produce the same amount of ATP when compared to anaerobic conditions.

less

FDA regulates chemicals used for

medical devices

The disinfectant action of phenol and phenolic derivatives mainly is due to

membrane damage and protein denaturation.

can be used as electron acceptors during anaerobic respiration?

nitrate sulfate carbon dioxide all of the choices

Purines and pyrimidines are precursors for synthesis of

nucleic acids

The chlamydias are

obligate intracellular parasites.

Low temperature storage is bacteriostatic to some bacteria and bactericidal to others. t/f

) True

The pentose phosphate pathway provides

ATP. NADPH. four- and five-carbon sugars for amino acid and nucleic acid synthesis.

Which of the following is a source of carbon skeletons that are used in the synthesis of amino acids?

Acetyl-CoA TCA cycle intermediates glycolysis intermediates Correct Answer all of the choices

What are highly resistant microbes

Bacterial endospores, Protozoan cysts and oocyst, enveloped viruses and naked viruses

The process by which chemolithoautotrophs and photo autotrophs use co2 to synthesis organic compounds is called

Carbon fixation

genera include bacteria with stalks?

Caulobacter

Allosteric regulation

Cells can quickly alter the activity of certain key enzymes, using other molecules that bind reversibly and distort them

Oxidative phosphorylase and

Energy from Exergonic reactions is used to create a proton motive force that drives the addition of P to ADP

Substrate level phosphorylation

Energy released and then Exergonic reaction is used to power the addition of P to ADP

Disinfectants are generally regulated by the

Environmental Protection Agency.

Which of the following is true about enzymes

Enzymes are catalysts that speed up reactions. Most of enzymes are proteins that can be denatured by changes in pH or temperature. Enzymes are highly specific for the substrates they react with and catalyze only one or a limited set of possible reactions with those substrates.

In terms of energy, the series of catabolic reactions by which a cell breaks down glucose are (blank). The energy released is then used to drive anabolic reactions in the cell that are (blank)

Exergonic; Endergonic

Antiseptics are generally regulated by the

FDA

In blank, cells breakdown glucose via glycolysis and then use pyruvate or a derivative as a terminal electron acceptor

Fermentation

Photosynthetic organisms use the light dependent reactions to accomplish to task

Generate ATP via photophosphorylation and generate reducing power

The three central metabolic pathways that gradually oxidize glucose to CO2 are

Glycolysis, the pentose phosphate pathway, the TCA cycle

Competitive inhibition

Inhibitor binds to the active site of the enzyme, blocking access of the substrate to that site. Competitive inhibitors such as sulfa drugs are used as antibacterial medications.

Noncompetitive inhibition (by regulatory molecules)

Inhibitor changes the shape of the enzyme, so that the substrate can no longer behind the active site. This is a reversible action that cells use to control the activity of allosteric enzymes.

Noncompetitive inhibition by enzyme poisons

Inhibitor permanently changes the shape of the enzyme, making the enzyme nonfunctional. & Poisons such as Mercury are used in certain antimicrobial compounds.

Gamma radiation

Is used to sterilize some food products.

Until the optimal temperature is reached, each 10°C rise in temperature has what approximate affect on the speed of enzymatic reactions?

It doubles the rate of the reaction

The TCA cycle completes the (blank) of glucose

Oxidation

In aerobic respiration, what serves as the terminal electronic acceptor

Oxygen

A brief heat treatment that reduces the number of spoilage bacteria and kills pathogens is

Pasteruization

A high solute or hypertonic solution, damages microbial cells causing

Plasmolysis

Some members of this group can use inorganic chemicals such as hydrogen sulfide and ammonia for energy

Prokaryotes only

Coxiella burnetii is responsible for

Q-fever.

Which of the following genera grow symbiotically within root nodules of legumes as nitrogen-fixing bacteroids?

Rhizobium

Precursor metabolites

Serve as carbon skeletons from which subunits of macromolecules can be made

The destruction or removal of all viable organisms is called

Sterilization

What part of the cell is changed by propionic, sorbic and benzoic aids affect?

The cell membrane function

Oxidative phosphorylation

The mechanism by which cellular respiration uses the reducing power generated in glycolysis, the transition step and the TCA cycle to synthesize ATP

Glycolosis

The pathway splits glucose and oxidizes it to form two molecules of pyruvate. Provides the cell with a small amount of ATP, some reducing power and six precursor metabolites.

Photophosphorylation

The suns radiant energy and any electron transport chain create a proton motive force that drives the addition of P to ADP

Ultraviolet radiation is an effective means of sterilizing surfaces (T/F)

True

Unlike the electrons carried by NADP H, the electrons carried by NADH and FADA

Used to generate proton motive force, transferred to the electron transport chain, used to produce ATP by oxidative phosphorylation

Unlike the electrons carried by NADH AND FADH, The electrons carried by NADP H are

Used to reduce compounds during biosynthetic reactions

Triclosan

a Phenolic, widely used in deodorant, soaps, lotions and toothpaste

The energy required to bring the substrates of a reaction together in the correct way to reach the transition state is called

activation energy

The substrate of an enzyme binds at the

active site

The synthesis of complex molecules from simpler ones with the input of energy is called

anabolism

The prevention of infection caused by microorganisms is called

antisepsis.

Members of the genus Pseudomonas

are aerobes that mineralize a wide variety of organic compounds.

Most myxobacteria

are micropredators because they secrete digestive enzymes that lyse bacteria and yeasts. have the ability to aggregate and form a fruiting body under conditions of nutrient limitation. produce desiccation resistant dormant myxospores.

Members of the genus Lactobacillus

are normal flora of the human body in mouth, intestinal tract and vagina.

You are working in a government laboratory in charge of destroying bioterrorism materials. An envelope containing the spore-forming bacterium that causes anthrax must be safely destroyed. What would be the best method for ensuring that the organism is killed?

autoclave

In the TCA cycle, two carbons are removed from citric acid in the form of __________, thereby regenerating oxaloacetate to complete the cycle.

carbon dioxide

Ionizing radiation kills microorganisms by

damaging DNA cytoplasmic membranes. producing reactive oxygen species.

Enzymes catalyze a reaction by

decreasing the activation energy of the reaction.

Although similar to eucaryotic photosynthetic organisms, cyanobacteria are different because they

do not have chloroplasts.

The infectious stage of chlamydiae is called a(n) _________ body

elementary

Mitochondrial electron transport takes place

on the inner mitochondrial membrane