lab exam 2 Flashcards
is transferred from one bacterium to another in solution.
“naked” DNA
are released as double-stranded DNA into the medium.
DNA fragments
cut the double-stranded DNA in solution and the resulting fragments separate—only single-stranded molecules are transferred.
Endonucleases
is spliced into the recipient cell’s DNA.
The transferred DNA
Transformation
occurs naturally among some bacteria. It is used in the laboratory to create recombinant DNA and is also used to study the effects of introducing DNA into a cell, and in mapping gene locations.
naked DNA
DNA Fragments
endonucleases
and transferred DNA are found in what process
transformation
is transferred from one bacterium to another via a “bacteriophage” and then incorporated into the recipient’s DNA
DNA during transduction
The bacterial virus may be
virulent or temperate.
Bacteriophages contain either
RNA or DNA
Some have taillike structure through w/ they inject their nucleic acid into the bacterial host cell.
bacteriophage
bacteriophage is used in what process to transfer DNA
transduction
If infecting virus (x) within the host cell & destroys it, the virus is said to be
“lytic or virulent”.
. If virus does not replicate but rather “integrates” into the bacterial chromosome, virus is said to be
“temperate/lysogenic
During conjugation the DNA is transferred
horizontally to cells without those cells undergoing replication
DNA is transferred from one live bacterium to another through what during conjugation
direct contact: large quantities of DNA can be transferred in this way.
F factors—
plasmids transferred from a donor cell (an F+) to a recipient cell (an F- cell) during conjugation
An Hfr (high frequency of recombination) is a cell with
with an F plasmid incorporated into the chromosome .
Before a cell can undergo “mitosis”, it must first duplicate its
genetic material
In the process, called DNA replication, the
original (parent) DNA strand acts as a template for the synthesis of a complementary (daughter) strand.
The first step in DNA synthesis is
unwinding or denaturation of the double-helix structure so replication may be carried out on each strand simultaneously, and bidirectionally. A variety of enzymes are required fro the “Replication” process.
Transposons
small DNA segments that can move from one part of the chromosome to another area on either the same chromosome, a different chromosome, or a plasmid.
Simple Transposons or insertion
is a short segment of DNA contain only those genes coding for the enzymes responsible for its transposition.
Complex transposons
can carry any type of gene.
DNA Helicase enzyme—are responsible
“unwinding the DNA helix” Unwinding the DNA helix increases coiling ahead of the replication fork, called supercoiling.
Topoisomerases-are
enzymes that “cut” one or both of the DNA strands to relieve the increased tension of unwinding the DNA helix & subsequently reseal the “cut ends”.
DNA polymerases
are enzymes that replicate complementary strands of DNA.DNA cannot replicate without RNA. DNA creates a model of the amino acids it needs by making a strand of mRNA.
RNA Polymerase
is used in the synthesis of transfer RNA. Transfer RNA (tRNA) collects amino acids from the cell’s cytoplasm and carries them back to mRNA for inclusion.
DNA ligase-is used in both
DNA repair and DNA replication. DNA ligases are essential for the joining of “Okazaki Fragments” during replication, & for completing short-patch DNA synthesis occurring in DNA repair process
Gene Recombination
involves the exchange of genetic material either between multiple chromosomes or between different regions of the same chromosome.
Recombination is used in DNA repair (particularly in
the repair of double-stranded breaks, As well as during DNA replication to assist in filling gaps & preventing stalling of the replication fork.
The Operon Model
is a group of genes coding for related proteins and arranged in units. An Operon consist of an; operator, promoter, regulator, and structural genes.
The regulator gene codes for a
repressor protein that binds to the operator, obstructing the promoter (thus transcription) of the structural genes.
Enzymes Induction
is the process in which it initiates or enhances the expression of an enzyme
ames test
method that uses bacteria to test whether a given chemical can cause mutations in the DNA of the test organism. More formally, it is a biological assay to assess the mutagenic potential of chemical compounds
bacteriocins
are proteinaceous or peptidic toxins produced by bacteria to inhibit the growth of similar or closely related bacterial strain(s). They are similar to yeast and paramecium killing factors
thermus aquaticus
Thermus aquaticus is a species of bacteria that can tolerate high temperatures, one of several thermophilic bacteria that belong to the Deinococcus–Thermus group.
southern blot
combines transfer of electrophoresis-separated DNA fragments to a filter membrane and subsequent fragment detection by probe hybridization.
metagenomics
is the study of genetic material recovered directly from environmental samples.
