MICRO230 CH9
gene (chromosome = cookbook, gene = recipe)
a(n) ____ is a sequence of DNA nucleotides that codes for one functional protein or RNA
codon
each mRNA ____ codes for a particular amino acid which is then bonded with other amino acids during translation to form a protein
transcription and translation
one reason protein synthesis is more efficient in bacteria than in eukaryotes is because bacterial ____ and ____ are simultaneous
iniation, elongation, termination
order of events in transcription (3)
bacteria, some fungi (plasmids: small, circular pieces of DNA that contain their own origin of replication and can replicated independently)
plasmids are found in which types of organisms?
the plasmid is integrated into the chromosome of an Hfr cell but not in an F+ cell
how do Hfr cells and F+ cells differ?
point
mutations that involve the addition, deletion, or substitution of no more than a few bases are referred to as ____ mutations
nonsense codon
stop codon is also a....
template
the _______ strand of DNA contains the order of nucleotides that are transcribed into RNA
Nucleotide
the basic structure of DNA is a .....
TTCAG
the complementary sequence to 5' AAGTC-3' is 3'_____ 5'
genomes smaller, enter host cell in RNA form, virus cycle occurs entirely in cytoplasm
which of the following are true of RNA viruses compared to DNA viruses?
reverse transcriptase
retroviruses contain the enzyme _____ _____
corepressor
A _____ binds to an inactive repressor to make an active repressor
phage bacteriophage is special virus that infects bacteria by injecting genetic material into bacterial cell
A _____ serves as the vector for transduction in bacteria
introns
after a eukaryotic mRNA has been transcribed, _____ are removed
mutagen
an agent that induces changes in DNA is a _____
herpesvirus, hepatitis B virus
Which viruses inset their DNA into the host genome increasing the risk of cancer?
transfer
____ RNA brings the amino acids to the ribosome
m (messenger)
____ RNA contains the codons for the polypeptide
transformation
____ involves the uptake of free DNA by competent bacterial cells
introns
_____ are DNA sequences found within a gene that do not encode the protein corresponding to the gene
transposons
_____ are able to shift from one part of the genome to another
structural
_____ genes code for proteins
conjugation
_____ in bacteria refers to horizontal gene transmission via pili
Heredity
_____ is another term for genetics - the study of inheritance in living things
transcription
_____ is the process of decoding DNA into messenger RNA
recombination
_____ refers to the transfer of genes from donor to recipient microorganisms, where the recipient strain shows a change in genetic makeup at the end
exons
_______ are DNA sequences which encode for functional proteins
chromosome
a ____ is a discrete cellular structure composed of a neatly packaged DNA molecule
conjugation
donor and recipient bacterial cells are connected by the sex pilus during
semiconservative
during ____ DNA replication, the newly made double helices are composed of one parent template and one newly synthesized strand
Translation
during ____ the information in mRNA is used to produce a protein
protein
during protein synthesis, many copies of a specific _____ can be synthesized from a single mRNA transcript
primase
during replication initiation, the enzyme _____ synthesized primer sequences
replication
during semiconservative ____ the DNA is duplicated prior to binary fission
transformation
during the process of _____ a competent bacterial cell may accept soluble DNA from the surrounding environment
elongation
during transcription _____, RNA polymerase moves along the DNA strand, adding complementary nucleotides to the mRNA strand
inducer (lactose stimulates the chain of events leading to protein synthesis)
lactose acts as an _____ in the lac operon
3'
nucleotides can only be added to the ____ end of a growing chain
makes RNA from DNA, unwinds DNA for transcription
functions of RNA polymerase?
operons
gene expression in prokaryotes is regulated through
RNA is single-stranded, in RNA uracil replaces thymine
how does RNA differ from DNA in bacteria and eukaryotes?
U instead of T, RNA single stranded with ribose
how does RNA differ from DNA in bacteria and eukaryotes?
2
how many replication forks are formed from opening a section of a circular DNA molecule during replication?
3
how many stop codons are contained within the genetic code?
binding of RNA polymerase to promoter region
initiation of transcription involves _____
DNA DNA is a blueprint that indicates which kinds of proteins to make and how to make them
the "blueprint' information for the production of proteins is permanently encoded in sections of _____
tRNA, mRNA, rRNA
the 3 types of RNA are ____, ____, and ____
promotor and operator
the ____ of an operon is the location where RNA polymerase binds, where as the ____ acts as the on/off switch for transcription of the structural genes
nitrogenous base (purines: guanine and adenine VS pyrimidines cytosine, thymine, uracil)
the _____ bases are either purines or pyrimidines
start
the _____ codon AUG of mRNA is associated with the tRNA anticodon UAC and the amino acid methlorine
regulator
the _____ is the gene that codes for a protein capable of repressing the operon
redundancy
the _____ of the genetic code results in several codons encoding the same amino acid
genotype, phenotype
the entire genetic makeup of an organism is its _____, but the expression of certain genetic traits are known as its _____
Helicase
the enzyme _____ unzips the DNA helix prior to the start of replication
III, I
the enzyme involved in replicating a new DNA strand is DNA polymerase ___, and DNA polymerase ___ is involved in removing the RNA primer, closing gaps, and repairing mismatched bases
polymerase
the enzymes responsible for building the DNA strand, proofreading newly produced DNA strands, and removing the RNA primer are DNA ____ I and III
ligase
the final sealing of nicks in a newly synthesized DNA strand is catalyzed by the enzyme _____
initiation, elongation, termination
the first three events in translation are _____, _____, _____ followed by protein folding and processing
DNA
the genome of a cell is entirely composed of the macromolecule known as:
RNA polymerase
the large enzyme complex involved in synthesizing RNA from a DNA template is called ____ _____
oncogenic
the mechanism of _____ transformation involve genes that can regular cellular genomes and control the onset of cell division
oncogenic
the mechanisms of ____ transformation involve genes that can regular cellular genomes and control the onset of cell division (cause cancer)
wild
the native or _____ type strain exhibits nonmutated characteristics
lagging strand
the newly formed DNA strand that is discontinuously replicated in segments (Okazaki fragments) is called the ____ strand
repressor
the protein product of a repressor gene is the ___ which binds the operator to stop transcription
Adenine
the purine nitrogenous bases found in RNA are guanine and _____
termination
the region of DNA that signals the end of an RNA transcript is the ____ sequence
ribosomal
the ribosome is composed of two subunits containing ____ RNA and protein
translation
the ribosome, composed of rRNA and protein, is involved in the process of _____
primary
the specific order of amino acids bound to each other by peptide bonds represents the ____ structure of a protein
translated
the ssRNA of positive-strand viruses come ready to be ____ into protein
separation of RNA from the DNA template
the termination of transcription involves.....
cancer
viral DNA inserted into the host genome may cause the transformation of the host cell into a _____ cell
AUG GCG .... Methionine alanine aginine aspartic acid glycine *remember that sequence will be reverse AND use uracil begins with start and ends with stop codons
what amino acid sequence is encoded by the DNA template sequence 3' TACCGCGTCTACCG 5'? look up genetic code figure in book
RNA polymerase: the enzyme that copies DNA into RNA synthesizes an RNA molecule from DNA template, unwinds DNA so that transcription can take place
what are functions of RNA polymerase?
operator, promotor, structural genes
what are the components of an operon in a sequence of DNA?
transcription and translation
what are the two stages needed for protein synthesis?
formyl metholnine is delivered to ribosome, enzymatic breaking of bond b/w tRNA and polypeptide chain what DOES occur: peptide bond forms b/w adjacent amino acids TE: joining AA with peptide bonds to form a polypeptide chain
what does NOT occur during translation elongation?
DNA encodes RNA which encodes protein
what is the central dogma hypothesis of genetics?
single or double stranded DNA or RNA
what is the genetic pattern of viral genomes?
abnormal bonds b/w adjacent pyrimidines so that normal replication is blocked
what is the main affect of UV radiation on DNA?
to determine the carcinogenic potential of a chemical
what is the purpose of the Ames test?
genetic material
what must be replicated before a cell can divide through binary fission?
p.260 starting amino acid clipped off, cofactors added, or join with other completed proteins to form quaternary structures
what occurs during posttranslational modification?
translocation of ribosome, tRNA delivers amino acid to empty A site, formation of peptide bonds between amino acids in A and P sites
what occurs during translation elongation?
enzymatic breaking of bond between tRNA and polypeptide chain
what occurs during translation termination?
ribose
what pentose sugar is found in RNA?
regulator, control locus (promoter and operator), structural locus
which are parts of the lactose operon?
carbons in the deoxyribose sugar
which component of DNA determines the 3' and 5' ends of the strands?
primase
which enzyme synthesizes primer sequences during replication initiation?
deoxyribose sugar, nitrogenous base, phosphate
which of the following are parts of a nucleotide in DNA?
tRNA
which of the following types of RNA delivers the amino acids to the growing peptide chain in translation?
protein
which organic molecule is formed from chains of amino acids?
operator
which part of the control locus acts as an on/off switch for transcription?
transduction (bacteriophage serves as carrier of DNA from donor to recipient cells) bacteriophages (bacterial viruses - can also serve as genetic vectors that bring foreign DNA into cells)
which recombination method involves transfer of DNA via bacteriophages?
leading
which strand is replicated continuously without segments during DNA replication?
triplet
which term, synonymous with codon, describes a trinucleotide sequence coding an amino acid in DNA?
rRNA ribosomes = moving protein factories (in ER in eukaryotes and cytoplasm in prokaryotes) made of rRNA and protein and site of protein synthesis in cell
which type of RNA comprises ribosomal subuints?
mRNA (copy of the DNA template that carries genetic information for the amino acid sequence of a protein. each codon contains 3 nucleotides that correspond to a specific amino acid which then make the protein)
which type of RNA is the transcribed version of a structural gene in DNA that is later read for translation into protein?
all types of RNA
which type of RNA is transcribed from a DNA template?
spontaneous mutations
which type of mutation is due to random mistakes in replication?
frameshift mutation
which type of mutation is most harmful to cells?
missense
which type of mutation results in a different amino acid being incorporated into a protein?
inducible operon: regulatory gene, control region (promotor + operator), and structural genes (on single mRNA) regulatory gene binds to operator and affects whether or not transcription of structural genes can take place control region contains promotor and operator and acts as on/off switch together, affect rate that structural genes transcribed so that the cell always has what it needs without wasting AAs
which type of operon is typically in the "off" position until the appropriate substrate is present?
III
DNA polymerase ___ is the enzyme responsible for building the DNA strand
positive
Gram - ______ cells conjugate and transfer genetic material through pores in their cell walls instead of pili
transformation (nonspecific acceptance by a bacterial cell of small fragments of soluble DNA from the surrounding environment)
Griffith's experiment using Strep. pneumoniae demonstrated the process of _____
conjugation horizontal gene transfer: organisms require genes which did not come directly from parent organisms vertical gene transfer: genes are acquired from parent organisms during reproduction conjugation, transformation, & transduction gene transfer in bacteria conjugation = horizontal gene exchange via pili transformation= bacterial cell accepts small fragments of DNA from surrounding environment transduction = transfer of genetic material from one bacterium to another through bacteriophage vector
R factors are specifically assosciated with with mechanism of recombination?
false (RNA polymerase)
T/F: DNA polymerase converts DNA into the various types of RNA during transcription
True
T/F: R-factors or "resistant factors" can be shared between bacteria through conjugation to help them survive the effects of antibiotics
FALSE frameshift mutation involves shift of triplet sequence vs point may also just include substitution of bases not shift
T/F: a point mutation results from an insertion or deletion of nucleotides and always leads to a shift of the triplet sequence from the point of mutation downstream
false bacteria have no equivalent to sexual reproduction - use conjugation for gene exchange via pili
T/F: bacterial conjugation is a sexual process
true
T/F: eukaryotic genes may also be regulated during growth and development leading to different tissue types
false (some F+ cells posess F plasmid separate from their chromosomal DNA. Hfr cells are only those in which the plasmid is integrated into the chromosome)
T/F: in bacterial conjugation, all F+ donor cells are high frequency recombinant (Hfr) cells
Genetics
The scientific study of heredity (the inheritance of living things)
nonsense (normal to stop and makes nonfunctional) silent (alters a base but doesn't change AA) back-mutation (reverses/mutates back to original base composition)
a _____ Mutation changes an amino-acid-producing codon into a strop codon, leading to premature termination of a protein
plasmid
a _____ is a small circular segment of DNA found in the cytoplasm of bacteria that is capable of independent replication and usually contains nonessential genes
frameshift
a ______ mutation results from the insertion or deletion of nucleotides in multiples of 1 or 2 leading to a shift of the triplet sequence from the point of mutation downstream
mutagen
a chemical or physical agent that induces a change in DNA is referred to as a ____
3
a codon contains how many nucleotides?
deoxyribose carbons
a nucleotide is orientated 5' or 3' depending on the location of the ____ on the strand of DNA
mutation
a permanent inheritable alteration in the DNA sequence of a cell is a(n) ________
Mutations
a small number of _____ are considered beneficial in that they provide the cell with a useful change in structure or physiology
5' to 3' in mRNA****
a strand of mRNA is constructed in the ____ to ____ direction
polymerase topolsomerase: unwinds double helix helicase: breaks hydrogen bonds holding strands together primase: syntheiszes RNA primer polymerase: adds nucleotides to new chain ligase: seals ends of short DNA pieces after splicing
an enzyme that is named for its ability to build strands of DNA is DNA _____
mutant
an organism that has a mutation is called a _____
AAC
if a codon of mRNA reads 5' UUG 3' the tRNA that delivers the amino acid to this location during translation will have an anticodon of 3' --- 5'
a pyrimidine (GC and ATU)
in DNA, a purine always combines with ....
antiparallel
in DNA, the two strands of the helix are arranged in ____ Orientation
2
in a chromosome, the DNA is composed of ____ strands
nucleus of eukaryotic cells
in a protozoal or fungal cell, chromosomes are located in the _____
F+
in bacterial conjugation, which term refers to a donor cell with a fertility plasmid located in the cytoplasm?
F-
in bacterial conjugation, which term refers to a recipient cell that does not have a fertility plasmid?
Hfr
in bacterial conjugation, which type of donor has the fertility factor integrated into the chromosome?
Okazaki
in replication of DNA, the lagging strand is replicated in a discontinuous manner forming ____ fragments
operons (section of DNA that contains one + structural genes with corresponding operator gene that controls transcription)
prokaryotic DNA is arranged into systems called _____
cytoplasm
protein synthesis takes place in the ____ of bacterial cells
enzymes, structural molecules
proteins contribute to the phenotype of an organism by functioning as ____
excision repair
proteins that remove incorrect bases and replace them with correct ones are termed _____ repair enzymes
