Microbiology: Exam 2

In eukaryotes, coding regions of DNA that will be translated into protein are called_________

Exons

T/F: ATP is composed of deoxyribose, adenine, and three phosphate groups.

F. Ribose Sugar and adenine ring, and three phosphate group

The movement of substances from higher to lower concentration across a semipermeable membrane that must have a specific protein carrier but no energy expenditure is called

Facilitated Diffusion

An organism that can exist in both oxygen and oxygen-free environments is a/n

Facultative Anaerobe

An organism that grows slowly in the cold but has an optimum growth temperature of 32° C is called a/n

Facultative Psychrophile

In bacterial cells, when glucose is completely oxidized by all the pathways of aerobic cellular respiration, what is the maximum number of ATP generated

38

Length of a typical tRNA molecule?

75-95 bases

Sulfonamides and Trimethoprim

Folic Acid Synthesis Inhibitors

T/F: Viral genomes are always composed of either single or double stranded DNA.

False. Include RNA

The duplication of a cell's DNA is called

Replication

The first three RNA nucleotides that signal the beginning of the message. The start codon is always AUG

Start Codon

The phase of the bacterial growth curve in which the rate of multiplication equals the rate of cell death is the

Stationary Phase

Mechanism of Resistance: Drug is immediately eliminated (occurs through the acquisition of new genes)

Stealth Mode

________________radiation excites atoms to a higher energy state within molecules such as DNA that then leads to the formation of pyrimidine dimers.

Ultraviolet

During replication, each parent DNA strand serves as a _____ for synthesis of new DNA strands.

Template

Groups of three consecutive bases along the DNA of a gene have the code for one:

amino acid.

What kind of RNA carries or brings the amino acids to the ribosomes?

Transfer RNA

RNA molecules is then used to produce proteins in a process known as

Translation

__________________________is the synthesis of proteins using RNA as a template.

Translation

Mechanism of Resistance: Binding sites for drugs are decreased in number and or affinity (occurs via mutation or through the acquisition of new genes) Pt 2 An Affected metabolic pathway is shut down or an alternative pathway is used (occurs via mutation or through the acquisition of new genes)

Up-Chuck

T/F: During protein synthesis, many copies of a specific protein can be synthesized from a single mRNA transcript

True

T/F: Hydrolysis reactions are catabolic reactions that use water to split the reactant into smaller subunits.

True

T/F: · Several codons code for the same amino acid which is called the redundancy of the code

True

· DNA from one parent organisms during reproduction.

Vertical Gene Transfer:

Main event of translation initiation mRNA ________________

binds to the ribosome

New enzymes are synthesized, inactivating the drug ( occurs through the acquisition of new genes))

Mechanism of Resistance

A permanent, inheritable change in the genetic information is called a/n

Mutation

Diffusion of water through a semipermeable membrane is called:

Osmosis

The most likely place where an exoenzyme participates in a chemical reaction is

Outside of the cell

In bacterial cells, the electron transport system is located in the:

cell membrane

Molecules called ____________________________ · can be made from messenger, transfer, ribosomal, and other forms of RNA.

complementary DNA (cDNA)

The pyrimidine nitrogenous bases found in DNA are

cytosine and thymine.

The movement of molecules from an area of high concentration to an area of lower concentration is called

diffusion

Surfactants work by

disrupting membrane integrity

Bacterial conjugation involves

donor cell with a plasmid that synthesizes a pilus.

The term obligate refers to

existing in a very narrow niche.

Full induction of the lactose operon requires

lactose present without glucose.

Another enzyme __________ is necessary to seal the sticky ends together by rejoining the phosphate-sugar bonds cut by endonucleases

ligase

The term used to describe all of the chemical reactions within a cell is:

metabolism

A permanent, inheritable change in the genetic information is called a/n:

mutation.

Each of the following is a mechanism for drug resistance transfer between microorganisms except

mutation.

The ________________ · DNA strand is the strand that is not directly used for transcription into mRNA during protein synthesis.

non-template

Electrons are ejected from atoms in cells when organisms are exposed to

gamma rays and X rays.

A technique that separates a readable pattern of DNA fragments is:

gel electrophoresis

A _____ is a specific segment of DNA that codes for the production of one functional product:

gene

short stretch of DNA of a known sequence that will base-pair with a stretch of DNA with a complementary sequence, if one exists in the test sample.

gene probes

Labeled, known, short stretches of DNA used to detect a specific sequence of nucleotides in a mixture are known as

gene probes.

Genetically modified organisms include:

o All of the above have been genetically modified. Bacteria o Viruses o Plants o nonhuman animals

Correct statements regarding eukaryotic transcription are correct?

o Transcription occurs before splicing. o The exon-intron junction is recognized by a spliceosome.

An organism that cannot tolerate an oxygen environment is a/n

obligate anaerobe.

All of the following pertain to transcription except

occurs on a ribosome in the cytoplasm

All of the following pertain to nitrogenous bases except:

guanine pairs with uracil.

The term facultative refers to

he ability to exist in a wide range of conditions.

The first genetically engineered protein approved for human use was:

human insulin.

Two different nucleic acids can _____ by uniting at their complementary sites:

hybridize

As the electron transport carriers shuttle electrons, they actively pump _____ into the outer membrane compartment, setting up a concentration gradient called the proton motive force.

hydrogen ions

Physical agents for controlling microbial growth include all of the following except

hydrogen peroxide.

Enzymes that catalyze the removal of electrons from one substrate and the addition of electrons to another are called

oxidoreductases.

During aerobic cellular respiration, the final electron acceptor is

oxygen.

An organism that uses CO2 for its carbon needs and sunlight for its energy needs would be called a

photoautotroph

versatile way to amplify DNA

polymerase chain reaction (PCR) -· technique rapidly increases the amount of DNA in a sample without the need for making cultures or carrying out complex purification techniques.

Amplification of DNA is accomplished by:

polymerase chain reaction.

RNA polymerase binds to the ____________ · to initiate transcription.

promoter region

_______ and ________ compose ribosome subunits.

rRNA and protein

The deliberate removal of genetic material from one organism and its subsequent transfer into the genome of another organism is a specific technique called

recombinant DNA technology

The pieces of DNA produced by restriction endonucleases are termed

restriction fragments.

The ___________ is a particle composed of two subunits of rRNA that is the site of protein synthesis.

ribosome

A halophile would grow best in:

salt lakes

Broad-spectrum drugs that disrupt the body's normal biota often cause

superinfections.

The term facultative refers to:

the ability to exist in a wide range of conditions

Antibiotic rifamycin can be used to treat tuberculosis because

the drug is more active against bacterial RNA polymerase than the human enzyme.

Helicase

unwinds DNA

This property, called ________ is thought to permit some variation or mutation without altering the message

wobble

Main event of translation termination?

· A nonsense codon is reached and the peptide is released from the ribosome.

is the formation of RNA using DNA as a template.

Transcription

DNA vs RNA

-RNA contains uracil (U) -backbone that consists of alternating sugar (ribose) -It is a single-stranded molecule that exists in helical form

The movement of substances from lower to higher concentration across a semipermeable membrane that must have a specific protein carrier and cell expenditure of energy is called:

Active transport

Which PCR step synthesizes complementary DNA strands?

Add DNA polymerase and nucleotides at 72° C.

· Transposable elements are capable of moving from

All TEs share the general characteristic of traveling from one location to another on the genome—from one chromosomal site to another, from a chromosome to a plasmid, or from a plasmid to a chromosome

Analysis of DNA fragments in gel electrophoresis is based on

All of the choices are correct. - Larger fragments moving slowly and remaining closer to the wells. - DNA having an overall negative charge and moving to the positive pole. - DNA fragments being stained so that they can be seen. - Application of an electric current through the gel causing DNA fragments to migrate.

Analysis of DNA fragments in gel electrophoresis is based on:

All of the choices are correct. -larger fragments moving slowly and remaining closer to the wells, - DNA having an overall negative charge and moving to the positive pole, - DNA fragments being stained so that they can be seen, application of an electric current through the gel causing DNA fragments to migrate)

Groups of three consecutive bases along the DNA of a gene have the code for one

Amino acids

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

Anabolism

Mechanism of Resistance: Permeability or uptake of the drug into the bacterium is decreased (occurs via mutation)

Ballistic Missile Defense

Opposite Sequence: The anticodon of the tRNA carrying the codon GUU=

CAA

Penicillins Cephalosporins Bacitracin Vancomycin

Cell Wall Inhibitors

Polymyxins

Cell membrane Inhibitors

What is the central dogma hypothesis of genetics?

DNA encodes RNA encodes protein.

Why is an enzyme from a thermophilic bacterium used in PCR?

DNA is replicated at a high temperature that denatures most proteins.

In the formation of recombinant DNA, what enzyme is needed to seal the sticky ends of genes into plasmids or chromosomes?

DNA ligase

A retrotransposon can transcribe______ into ______ and then back into DNA for insertion in a new genomic location

DNA, RNA

DNA from a source other than the parent organisms.

Horizontal Gene Transfer:

Base pairs in DNA are held together by _____ bonds.

Hydrogen

____________are DNA sequences found within a gene that do not encode the protein corresponding to the gene

Introns

Fluoroquinolones Rifampin

Nucleic Acid Inhibitors

What are areas of the genome where multiple genes exist that are coordinated to give a new trait and make the bacteria more pathogenic

Pathogenicity islands.

Antibiotic tha does NOT target transcription or translation in bacteria?

Penicillin

Which process in bacteria do the antibiotics tetracycline,chloramphenicol and erythromycin specifically inhibit?

Protein Synthesis

Erythromycin Clindamycin Aminoglycosides Tetracyclines

Protein Synthesis Inhibitors

Primaquine and chloroquine are drugs used in the treatment of ___ infections.

Protozoan

During Transcription RNA polymerase synthesizes _____ and _______template.

RNA and DNA template

Gene regulation can involve a protein repressor that blocks ..... from initiating transcription.

RNA polymerase

The antibiotic rifamycin, used to treat tuberculosis, binds and inhibits the activity of

RNA polymerase

· Which of the following is the genetic pattern of viral genomes?

Single or double stranded DNA or RNA

gel electrophoresis

The separation of nucleic acids or proteins, on the basis of their size and electrical charge, by measuring their rate of movement through an electrical field in a gel. -· give the entire molecule an overall negative charge, which causes the DNA to move toward the positive pole in the gel

Reverse transcriptase is used to make cDNA from an RNA template.

True

The cellular basis for bacterial resistance to antimicrobials include

a. All of the choices are correct. - bacterial chromosomal mutations. - synthesis of enzymes that alter drug structure. - prevention of drug entry into the cell. - alteration of drug receptors on cell targets.

Alcohols

a. All of the choices are correct. -denature proteins when in a 50-95% alcohol-water solution. -disinfect items when soaking method is utilized. -are skin degerming agents. -at 50% or higher concentrations dissolve cell membrane lipids.

Semiconservative replication refers to:

an original parent DNA strand and one newly synthesized DNA strand comprising a new DNA molecule.

semiconservative replication refers to

an original parent DNA strand and one newly synthesized DNA strand comprising a new DNA molecule.

The alcohol wipe used on a patient's skin before an injection is an example of

antisepsis.

The bacterial genus Bacillus can utilize starch as a nutrient by splitting the starch molecule into smaller molecules of glucose, with the addition of water. The enzymes to do this would be classified as:

hydrolases.

Enzymes are:

proteins that function as catalysts

Enzymes are

proteins that function as catalysts.

All of the following could find a location in or on body tissues suitable for growth except

psychrophiles

During _____________________RNA polymerase synthesizes a strand of mRNA from template DNA.

transcription elongation

The process of ______________________· results in the release of a completed RNA transcript.

transcription termination

The RNA molecules that carry amino acids to the ribosomes during protein synthesis are called

transfer RNA

The transfer of DNA fragments from a dead cell to a live, competent recipient cell that results in a changed recipient cell is termed

transformation.