question

Chromosome

answer

A structure in the nucleoid or cell nucleus that carriers hereditary information in the form of genes; thread-like fibers associated with some protein and is located in the cytosol within the nuceloid

question

Nucleoid

answer

The chromosomal region of a bacterial and archaeal cells

question

Haploid

answer

Having a single set of genetic information spread across multiple chromosomes

question

Supercoiling

answer

The process by which a chromosome is twisted and packed

question

Supercoiled Domain

answer

A loop of wound DNA consisting of 10,000 bases

question

Looped Domain Structure

answer

The term used to describe organization and packing of the prokaryotic chromosome

question

Plasmids

answer

A small, closed loop molecule of DNA apart from the chromosome that replicates independently and carriers nonessential genetic information; stable extrachromosomal DNA elements that do not carry genetic information essential for normal structure, growth, and metabolism; easily transferred between cells and replicate and exist in the cytosol

question

F Plasmids

answer

A DNA plasmid in the cytoplasm of an F+ bacterial cell that may be transferred to a recipient bacterial cell during conjugation; transfer genetic material from donor to recipient through a recombination process

question

R Plasmids

answer

A small, circular DNA molecule that occurs frequently in bacterial cells and carriers genes for drug resistance

question

Bacteriocins

answer

One of a group of bacterial proteins toxic to other bacterial cells

question

DNA Replication

answer

the process of copying the genetic material in a cell; occurs within such precision that the two daughter cells from binary fission are genetically identical to the parent cell

question

Initiation

answer

1) The unwinding and separating of DNA strands during replication 2) the beginning of translation

question

Elongation

answer

1) The addition of complementary nucleotides to a parental DNA strand 2) The addition of addition of amino acids onto the forming polypeptide during translation

question

Termination

answer

1) The completion of DNA synthesis during DNA replication 2) The release of a polypeptide from a ribosome during translation

question

Semiconservative Replication

answer

The DNA copying process where each parent (old) strand serves as a template for new complementary strand; Each old strand of replicated DNA is conserved in each new chromosome and one strand is newly synthesized

question

Replication Origin (OriC)

answer

The fixed point on a DNA molecule where copying of the molecule starts

question

Base Pairs

answer

The complementary pairing of A-T and G-C on the two opposite polynucleotide strands

question

Replication Factories

answer

The location in a cell where DNA synthesis occurs

question

Helicases

answer

the helix shape of the DNA that unwind and unzip the two polynucleotide strands

question

Stabilizing Proteins

answer

A protein that keeps the DNA template strands separated during DNA replication

question

Replication Fork

answer

The point where complementary strands of DNA separate and new complementary stands are synthesized

question

Elongation

answer

Synthesis of DNA in each factory then occurs on each old strand, which represents a template for the synthesis of a new complementary strand

question

DNA Polymerase III

answer

An enzyme that catalyzes DNA replication by combining complementary nucleotides to an existing strand
> detect any mismatched nucleotides, remove the incorrect nucleotide in the pair and add the correct nucleotide

question

Mutations

answer

Permanent alterations in DNA base sequences

question

Termination

answer

Two replication forks meet 180O from oriC at the terminus region where there are additional terminator proteins that block further replication causing the replication factories to dissociate

question

Termination

answer

Then the two intertwined DNA molecules (chromosomes) are separated by other enzymes, guaranteeing that each daughter cell will inherit one complete chromosome after binary fission

question

3'-5' Direction

answer

DNA polymerase only reads the template DNA in this direction

question

two parental (template) strands

answer

these two things are antiparallel, meaning that at each replication fork the complementary DNA strand is formed into two different ways

question

Leading Strand

answer

During DNA replication, the new strand that is synthesized continuously, here the DNA polymerase reads the template in the 3’-5’ direction, bring the triphosphate nucleotides (A,T,G,C) that hydrogen bond with their complement in the template strand

question

The high energy bonds in the triphosphate nucleotides in the leading strand

answer

The energy for the DNA polymerase to covalently bond nucleotides into continuous strands, forming nucleotides into a continuous strand, formining an elongating chain of nucleotides from 5'-3'

question

template strand

answer

in each fork of replication, what strand is read backwards?

question

Lagging Strand Synthesis
Template strand are read backwards

answer

DNA polymerase moves away from the replication fork, a discontinuous process of starts and stops occuring with the new strand always behind the leading strand. Why is this?

question

Lagging Strand

answer

During DNA replication, the new strand that is synthesized discontinuously

question

Okazaki Fragments

answer

A segment of DNA resulting from discontinuous DNA replication

question

DNA Ligase

answer

An enzyme that binds together DNA fragments

question

Initiation of the DNA Replication

answer

• Replication of the circular bacterial chromosome begins at a fixed region on the DNA called the oriC, where copies of initiation proteins bind to the oriC DNA sequences.The other proteins needed for replication will then add to this so called replication factory

question

Elongation of DNA Replication

answer

The replication factories are attached to the cell membrane and consist of a variety of enzymes needed to unwind, separate, and synthesize a complementary strand. Therefore, as replication continues, unreplicated (parental) DNA is pushed through a replication factory at a replication fork, synthesizing a complementary strand to the template strand forming the elongating DNA loops. Because the two parental DNA strands are antiparallel, replication involves leading and lagging strands synthesis at the replication fork in each replication factory

question

Termination of DNA Replication

answer

Replication comes to completion when the replication factories reach a terminus region opposite the oriC in the chromosome. At the terminus, proteins bind and the replication factories disperse. Each daughter chromosome consists of one old parental strand and one newly synthesized strand

question

Protein Synthesis

answer

The process of forming a polypeptide or protein through a series of chemical reactions involving amino acids

question

Transcription

answer

The biochemical process in which RNA is synthesized according to a code supplied by the template strand of a gene in he DNA molecule; DNA > RNA

question

Genetic Code

answer

The sequence of bases in the DNA or codons in the RNA that specify a specific polypeptide

question

Translation

answer

The biochemical process in which the code on the mRNA molecule is converted into a sequence of amino acids in a polypeptide RNA> Protein Synthesis

question

Central Dogma

answer

The doctrine that DNA codes for RNA through transcription and RNA is converted to protein through translation DNA> RNA > Protein Synthesis

question

Transcription

answer

The biochemical process in which RNA is synthesized according to a code supplied by the template strand of a gene in he DNA molecule; DNA > RNA; the process of expressing a number of these genes at a particular time so the gene DNA serves as a template for a new RNA molecule

question

RNA Polymerase

answer

the enzyme that synthesizes an RNA polynucleotide from a DNA template; reads the DNA template strand in the 3’-5’ direction, but only one of the two DNA strands within a gene is transcribed; recognizes this template by sequence of bases called promotors

question

Promotor

answer

The region of a template DNA strand or operon to which RNA polymerease binds and the unwinds the helix and separates the two strands within a gene ; where the initiation phase starts

question

RNA polymerase
the elongation phase
guanine (G) to Cytosine (C)
Thymine (T) to Adenine (A)
for RNA
G-C
Uracil (U) to Adenine (A)

answer

As ____ moves along the DNA Template strand during ____ phase, complementary pairing brings RNA triphosphate nucleotides to the template strand. What are the complementary base pairing for DNA and RNA?

question

Terminators

answer

specific base sequences on the DNA template strand that signal termination of transcription

question

All 3 Types of RNA

answer

What are the 3 things required when the products of transcription go over to translation?

question

RNA polymerase
promotor

answer

DNA-directed RNA synthesis is a gene catalyzed by ___ and starts at a control sequence called ___ which is found on the template strand

question

RNA polymerase

answer

transcribes the template substituting uracil for thymine where adenine appears in the DNA template strand

question

Terminators

answer

In Bacteria and Archaea, it stops at DNA sequences called ____, resulting as a single polynucleotide strand

question

Messenger RNA (mRNA)

answer

it carries the genetic information or “blue print” to manufacture a polypeptide, Each is transcribed from a different gene carries a different message, a different sequence of nucleotides coding for a different polypeptide, usually an encoded series of three base codes called codons

question

Codons

answer

A three base sequence of the mRNA molecule that specifies a particular amino acid insertion in a polypeptide

question

Ribosomal RNA (rRNA)

answer

serves a structural role as the framework for the ribosomes, which are the sites at which amino acids assemble into proteins, they also serve a functional role in the translation process

question

Transfer RNA (tRNA)

answer

looks like a cloverleaf, one point presents a sequence of three nitrogenous bases which function as anticodons; structural role in delivering amino acids to the ribosome for assembly into proteins; each has a specific amino acid attached through an enzymatic reaction involving ATP

question

introns

answer

the non-coding sequence in a split gene; have roles in gene regulation or in metabolic control through association with other RNAs or proteins

question

Exons

answer

the coding sequence in a split gene; have the “standard” information coding for a polypeptide

question

Genetic Code

answer

The sequence of bases in the DNA or codons in the RNA that specify a specific polypeptide

question

Sense Codons

answer

A nucleotide sequence that specifies an amino acid

question

Redundancy

answer

referring to multiple codons coding for the same amino acid

question

Start Codon

answer

The starting nuelotide sequence (AUG) in translation

question

Stop Codon

answer

The nucleotide sequence that terminates translation (UGA, UAG, UAA)

question

Protein Synthesis (part 1)

answer

1. Each gene of the DNA contains information to manufacture a specific form of RNA

question

Protein Synthesis (part 2)

answer

2. The information can be transcribed into:
a. mRNAs which are produced from genes carrying the information as to what protein will be made during translation
b. rRNAs which form part of the structure of ribosomes and help in the translation of the mRNA
c. tRNAS each of which carries a specific amino acid needed for the translation process

question

Protein Synthesis (part 3)

answer

3. With the tRNAs and mRNAs present in the cytosol, they can combine with ribosomes to manufacture specific cellular polypeptide [protein]

question

Translation

answer

the language of the genetic code (nucleotides) is translated into the language of proteins (amino acids); Three stages: Chain initiation, Elongation, and termination

question

Formylmethionine (fmet)

answer

the presence of a formyl group (H-CO--) attached to methionine;In Bacteria it is the first amino acid, while in Archaea and Eukarya it is methionine (met)

question

Ribozyme

answer

An RNA molecule capable of carrying out a chemical reaction; transfers fmet to the amino acid on the second tRNA

question

Chain Initiation

answer

Begins with the association of a small ribosomal subunit with an initiator tRNA at the AUG start codon; then the large ribosomal subunit was added to form the functional ribosome with three tRNA binding sites called A, P, and E

question

Chain Elongation

answer

With the second tRNA attached, the first tRNA is released from the E site. Moving right one codon, the ribosome exposes the next codon (GCC) and the appropriate tRNA with the amino acid alanine (ala) attached; Again a ribozyme transfers the dipeptide fmet-Ser to alanine. The tRNA that carried serine excited the ribosome and the process of chain elongation continues as the ribosomes moves to expose the next codon

question

Chain Termination/Release

answer

process of adding tRNAs and transferring the elongating polypeptide to the entering amino acids/tRNA at the A site continues until the ribosome reaches a stop codon, there is no tRNA to recognize any of these stop codon but proteins called termination factors triggers the termination

question

Termination Factors

answer

A protein that triggers the release of a polypeptide from a ribosome and a disassembly of the ribosome subunits, which can be reassembled for translation of another mRNA

question

Chaperones

answer

a protein that ensures a polypeptide folds into the proper shape

question

Polysome

answer

A cluster of ribosomes linked by a strand of mRNA and all translating the mRNA

question

Chain Initiation

answer

Starts with the translation components [small ribosomal subunit, initiator tRNA, and other protein factors] assemble on the start codon. The large ribosomal subunit then associates to form a functional ribosome with three binding sites: A, P, E. After the initiator tRNA binds to the P site, the next tRNA can bind to the A site. Ribozyme of the large subunit then transfers the amino acid from the first tRNA onto the tRNA in the A site

question

Chain Elongation

answer

Once the functional ribosome has been formed, translation is a process of adding new amino acids, one at a time, to the forming polypeptide chain: the process involves:
- the addition of the appropriate tRNA to the A site
- the transfer of the amino acid chain from the amino acid in the P site
- the loss of a former tRNA from the E site. The ribosome then moves down one codon and the process repeats; the result is an elongating amino acid sequence

question

Chain Termination

answer

Chain elongation continues until the A site covers a stop codon (UGA, UAG, or UAA) to which there is no corresponding tRNA

question

1. The release of the polypeptide chain from the P site
2. The disassociation of the ribosome into subunits
3. The release of the empty tRNA and termination factor

answer

What 3 Things does the termination factor cause when binding to a site?

question

Antibiotic

answer

interfere with transcription and protein synthesis

question

Rifampin

answer

binds to the RNA polymerase so that transcription cannot initiate

question

Antibiotic

answer

inhibit translation by binding to the bacterial 30S or 50S ribosomal subunit

question

Tetracycline

answer

prevents chain initiation by binding to the 30S subunit

question

Chloramphenicol and erythromycin

answer

these 2 drugs inhibit chain elongation by binding to the 50S subunit

question

Transcription
A way protein synthesis can be controlled

answer

_____ is the first step leading to protein manufacture in cells, to control what proteins and enzymes are present in bacterial and archaeal cells is to regulate the mechanisms that induce (“Turn on”) or repress (“turn off”) _____ of a gene or set of genes. What is This an example of?

question

Operons

answer

The unit of bacterial DNA consisting of a promoter, operator, and a set of structural genes

question

Structural Genes

answer

A segment of DNA molecule that provides the biochemical information for a polypeptide; provides genetic codes for proteins often having metabolically related functions so bacterial and archaeal cells can co-regulated genes needed in the same functional or metabolic pathway

question

Operator

answer

A sequence of bases in the DNA to which a repressor protein can bind

question

Promotor

answer

The region of a template DNA strand or operon to which RNA polymerase

question

Regulatory Gene

answer

A DNA segment that codes for a repressor protein

question

Repressor Protein

answer

A protein that when bound to the operator blocks transcription

question

Repressor Proteins

answer

binds to the operator, binding prevents the RNA polymerase from moving down the operon and thus cannot transcribe the structural genes

question

Negative Control

answer

A form of gene regulation where a repressor protein binds to an operator and blocks transcription

question

Negative Control

answer

When the repressor in some way is prevented from binding to the operator, the RNA polymerase has clear sailing and transcribes the structural genes, which then are translated into the final polypeptides

question

RNA Polymerase
Bacillus subtilis

answer

concentrated within the nucleoid core in the central portion of the cell, so then it is assumed that most of the cell’s transcription occurs there. Name an example

question

Mutations

answer

A permanent alteration of a DNA sequence; involves a disruption of the nitrogenous base sequence in the DNA molecule,

question

Mutations

answer

from this the production of a miscoded mRNA, and ultimately the insertion of one or more incorrect amino acids into the polypeptide during translation can occurs. Because proteins govern numerous cellular activities, they can also be altered

question

Spontaneous Mutation

answer

A mutation that arises from natural phenomena in the environment

question

Spontaneous Mutation

answer

can be from everyday radiation penetrating the atmosphere or errors made and not corrected by DNA polymerase III during replication

question

Wild Type

answer

The common or native form of a gene or organism

question

Wild Type

answer

Should the mutant survives it may multiply and emerge as the predominant form

question

Niche

answer

The functioning of a species in relation to other species and its physical environment

question

Induced Mutation

answer

A change in the sequence of nucleotide bases in a DNA molecule arising from mutagenic agent used under controlled laboratory conditions

question

Mutagens

answer

A chemical or physical agent that causes a mutation

question

Ultra Violet Light
Physical Mutagens

answer

the energy induces agent thymine (or cytosine) bases in the DNA to covalently link together forming dimers (if these dimers occur in a protein-coding gene, the RNA polymerase cannot insert the correct bases (A-A) in mRNA molecules where the dimers are located). What is this an example of?

question

Nitrous Acid
Chemical Mutagens

answer

it converts DNA’s adenine bases to hypoxanthine bases, which causes a base pairing with cytosine after replication, so later replications from the gene with cytosine mutation, the mRNA will contain guanine rather than adenine. What is this an example of?

question

Base Analogs

answer

A nitrogenous base with a similar structure to a natural base but differing slightly in composition

question

5-Bromouracil
Base Analogs

answer

which bears close resemblance with thymine
What is this an example of?

question

Base Analogs
Herpesvirus

answer

What are useful as antiviral agents in the treatments of disease caused by DNA viruses. Name an example of a virus it can treat?

question

acyclovir
decreases the frequency and severity of fever blisters/cold sores
base analogs

answer

substitute for guanine during viral replication, and blocks viral replication, so new virus particles cannot be produced. What is this an effective treatment for? What is this an example of?

question

Point Mutations

answer

the replacement of one base in a DNA strand with another base; affects just one point (base pair) in a gene, may be a change to or substitution of a different base pair or a deletion or addition of a base pair

question

Base Pair Substitutions

answer

if a point mutation causes a base-pair substitution, then the transcription of that gene will have one incorrect base in the mRNA sequence of codon
Normal Sentence: THE FAT CAT ATE THE RAT
Substitution: THE FAT CAR ATE THE RAT

question

silent Mutation

answer

the base pair substitution does not result in any change in the codon

question

Missense Mutation

answer

This Base Pair Substitution leads to the insertion of the wrong amino acids

question

Nonsense Mutation

answer

This base pair substitution generates a stop codon

question

Base Pair Deletion and Insertion

answer

Point mutations can cause the loss or addition of a base in a gene, resulting in an inappropriate number of bases
Normal Sentence: THE FAT CAT ATE THE RATE
Deletion: THE F_TC ATA TET HER AT
Insertion: THE FAT ACA TAT ETH ERA T

question

Base Pair Deletion or Insertion of Point Mutations

answer

Ribosomes read one codon (three letters) at one time, generating potentially extensive mistakes in the amino acid sequence, so the loss or addition of a base shifts the reading of the code by one base, resulting in serious sequence errors in the amino acids, which will produced an abnormal protein (nonsense) unable to carry out its role in metabolism

question

Mismatch Repair

answer

A mechanism to correct mismatched bases in the DNA; As the DNA polymerase adds new complementary bases to the DNA template strand during replication, it makes mistakes, so as it adds bases, it also “proofreads” it work and removes mismatched nucleotides

question

Excision Repair
Deinococcus radiodurans

answer

A mechanism to correct improperly bonded bases in a DNA sequence (physical mutagens); First, nucleases cut out (excise) the damaged DNA, then a different DNA polymerase from the one used in replication replaces the missing nucleotides with the correct ones. Finally, DNA ligase seals the new strand into the rest of the polynucleotide. Name an example.

question

Transposable Genetic Element

answer

Fragments of DNA called insertion sequences or transposons that can cause mutations

question

Insertion Sequence (IS)

answer

segment of DNA that forms a copy of itself, after which the copy moves into areas of gene activity to interrupt the genetic coding sequence

question

Insertion Sequence (IS)

answer

have no genetic information other than for the ability to insert into a chromosome, they produce copies of themselves and the copies move into other areas of the chromosomes; can be a prime source of spontaneous mutation

question

Transposons

answer

A segment of DNA that moves from one site on a DNA molecule to another site, carrying information for protein synthesis; “jumping genes”

question

Transposon

answer

larger than IS and carry additional genes for various functions, like antibiotic resistance, but they interrupt the genetic code of a gene

question

Transposon

answer

jumps away from its location and nothing takes its place, so they move from plasmid to plasmid, from plasmid to chromosome, or from chromosome, to plasmid; inverted repetitive base sequences at the ends of the element appears to help the ability to move

question

Transposon

answer

many contain genes for antibiotic resistance and can transfer this quality
- e.g. if a plasmid containing a ___ is transferred from one bacterial cell to another, the _____ will move along with it, spreading the genes for antibiotic resistance

question

Mutant

answer

An organism carrying a mutation

question

Wild Type

answer

The common or native form of a gene or organism; Should the mutant survives it may multiply and emerge as the predominant form

question

Phenotype

answer

The visible (physical) appearance of an organism resulting from the interaction between its genetic makeup and the environment

question

Selection

answer

a technique to identify and isolate a single mutant from among thousands of possible cells or colonies

question

Nutritional Mutant

answer

When this is unable to grow without the amino acid histidine, this mutant (written his-) has lost the ability that the wild type strain (his+) has to make its own histidine

question

Plating Technique Select for Specific Mutants or Characteristics

answer

the chemical composition of the transfer plate is key to visual identification of the colonies being hunted. The use of a replica plating device makes the identification possible. The device consists of a sterile velveteen cloth or filter paper mounted on a solid support. When an agar plate (master plate) with bacterial colonies is gently pressed against the surface of the velveteen, some cells from each colony stick to the velveteen. If another agar plate then is pressed against this velveteen cloth, some cells will be transferred (replicated) in the same pattern as on the master plate

question

Auxtroph

answer

A mutant strain of an organism lacking the ability to synthesize a nutritional need

question

Prototroph

answer

An organism that contains all its nutritional needs

question

Negative Selection

answer

A method for identifying mutations by selecting cells or colonies that do not grow when replica plated (auxotroph) (his-)

question

Positive Selection

answer

A method for selecting mutant cells by their growth as colonies on agar (prototroph) (his+) (identification of tetracycline resistant mutants)

question

Carcinogens

answer

Any physical or chemical substance that causes tumor formation and cause mutations in bacterial cells

question

Ames Test

answer

diagnostic procedure used to detect potential cancer causing agents in humans by the ability of the agent to cause mutations in bacterial cells

question

Ames Test

answer

an auxotrophic, histidine requiring strain (his-) of Salmonella enterica serotype Typhimurium is used. If inoculated onto a plate of nutrient medium lacking histidine, no colonies will appear because in this auxotrophic strain the gene inducing histidine synthesis is mutated and not active

question

Ames Test

answer

the potential carcinogen is mixed with a liver enzyme preparation before the test, this is because chemical only because tumor causing and mutagenic in humans after they have been modified by liver enzymes

question

Screening Test

answer

A process of detecting mutants by examining numerous colonies

question

Revertants

answer

referring to a mutant organism or cell that has reacquired its original phenotype or metabolic activity

question

Revertants

answer

referring to a mutant organism or cell that has reacquired its original phenotype or metabolic activity

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