Upgrade to remove ads
Terms in this set (77)
What do all nucleotides consist of?
Phosphate, Nitrogenous base, Pentose
basic unit of heredity made of a sequence of nucleotides
What are two differences between prokaryotic and eukaryotic DNA?
1. Percentage of G and C content(G/C content higher in prokaryotes primarily adenine
2. DNA methylation(methyl group CH3)
C is methylated in Eukaryotes, Adenine is primarily methylated
The site where DNA replication starts is called the ___
origin of replication
Why is DNA replication said to be semi-conservative?
Each daughter DNA is composed of one original strand and one new strand
Transcription is the making of ___ from ____
DNA replication is the making of _____ from _____
What is the function of rRNA?
binds to ribosomal proteins to form the two ribosomal subunits
Each codon specifies one _____ or ______
amino acid or terminator
The first amino acid of every protein is always _____
What is the terminator triplet bases? What other name are they called?
UAA, UAG, UGA; terminator codons
What is the function of tRNA?
brings amino acids from the cytoplasm to the ribosomes to make a protein
At one end of the tRNA you will find an _____ while at the other end you will find _____.
Each anticodon is complementary to what?
1a. RNA polymerase attaches nonspecifically to DNA and travels down it length until it recognizes a promoter sequence. Sigma factors enhances promoter recognition in bacteria.
1b. Upon recognition of the promoter, RNA polymerase unzips the DNA molecule beginning at the promoter
2. Triphosphate ribonucleotides align with their DNA complements and RNA polymerase links them together, synthesizing RNA. No primer is needed. The triphosphate ribonucleotides also provide the energy required for RNA synthesis
3a. Self-termination: transcription of G-C rich terminator region produces hairpin loop, which creates tension, loosening the grip of the polymerase on DNA
3b. Rho-dependent temination: Rho pushes between polymerase and DNA. This causes release of polymerase, RNA transcript and Rho.
Translation is the making of ____ from ____
a protein, mRNA
The 5 steps involved in translation are:
1. Ribosomes attaches to mRNA
2. tRNA anticodon attaches to the matching mRNA codon
3. A second tRNA attaches at next codon on mRNA
4. Peptide bond forms enzymatically between first two amino acids
5. Ribosomes move along mRNA as next tRNA attaches to next codon
What does an operon consist of?
a promoter and a series of genes
An inducible operon must be activated by _____. The _____ operon is example of an inducible operon.
Repressible operons are transcribed _____, and must be deactivated by _____. The _____ operon is an example of a repressible operon.
continually, repressors, tryptophan
Name a disease that can occur from lack of the ability to repair UV-induced DNA damage
skin cancer, xeroderma pigmentosum
exchange of nucleotide sequences between 2 DNA molecules that are composed of identical nucleotide sequences homologous sequences
horizontal gene transfer
getting genes from other microbes of the same generation; donor cell contributes part of the genome to a recipient cell which may species from the donor
Heat-killed, smooth pneumococci with capsule only:
Live, smooth pneumococci, with capsule only
mouse is killed
Live, rough pneumococci, no capsule only
Heat-killed, smooth pneumococci with capsule + live, rough pneumococci without capsule together
mouse is killed
Who discovered the process of transduction?
Joshua Lederberg and Norton Zinder
What are the two bacteriophage cycles and how do they work?
Lytic cycle: phage inject its DNA into the bacteria causing the host DNA to break apart. leaving the DNA alone. The phage replicates into more viruses lysing the cell
Lysogenic: phage inserts its DNA and intergrates itself into the host's DNA. The cell replicate(divide transfering it's DNA
the sum of all genes in an organism
the nucleic acid sequence that encodes for a specific phenotype
observable characteristics of an organism
What is changed as a result of mutations?
What is a genetic mutation?
a change in the nucleic acid sequence of an organism
What is a point mutation?
a genetic mutation affecting one or a few base pairs in a genome
What is the name of the disease that is caused by a single point mutation and confer some resistance to malaria?
Sickle cell anemia
What is the amino acid change that leads to sickle cell anemia?
hydrophilic glutamic acid becomes hydrophobic valine
What are two ways mutations occur?
Spontaneous mutation, induced mutations
-occur in absence of chemical inducer
-impossible to predict
-can be a result of error in DNA replication
-occur as a result of exposure to a mutagen
-chemical that induces changes in DNA
-increases rate of mutation ABOVE spontaneous mutation rate
5-Bromouracil is an example of what kind of mutation?
How does 5-Bromouracil cause mutations?
alter sequences of bases in DNA
The longer the wavelength the ____ the energy
The shorter the wavelength the ____ the energy
Is UV light a shorter or longer wavelength than visible light?
the transfer of LARGE amounts of DNA from one bacterium to another that requires physical contact between the two bacteria
transfer of "naked" DNA from one bacterium to another, results in a change of the organism's characteristics
-encodes for F pilus(aka: sex pilus or conjugation pilus)
-Also contains other genes that get transferred to the F-cell
How are F' plasmids formed?
When Hfr plasmids separate from the chromosome and take chromosomal DNA with them
contain genes that direct synthesis of the conjugation pilus
Resistance plasmids (R plasmids)
carry genes that provide resistance to antibiotics
carry genes that cause disease signs and symptoms (ex: neruotoxin of Clostridium tetani)
produce growth inhibiting bacteriocins effect strains of the same species
What are four most commonly used antibiotics that a few bacteria have gained resistance to?
Sulfanilamide, Chloramphenicol, Tetracycline, Streptomycin
What do the two types of transduction correspond to these 2 cycles(lytic and lysogenic)?
Generalized: any gene can be incorporated in the phage
Specialized: specific bacterial genes (one or two) are transferred in the phage
DNA replication is _____
2. DNA synthesis is bidirectional
What type of organisms were recovered from the mouse after the experiment?
live smooth pneumococci (with capsule) plus live rough pneumococci (without capsule)
resistance genes move to plasmids and/or chromosomal DNA
Do F' plasmids get incorporated into the chromosomal DNA?
The F' plasmids generally do not get incorporated into the chromosomal DNA
How are F' cells formed?
F' cells conjugate with F- cells transferring the whole plasmid (along with chromosomal DNA)
What two mechanisms do some organisms have to repair UV induced DNA damage?
Which type of cells become Hfr cells? After conjugation, are these cells F+ or F-?
enzyme that adds RNA primer
DNA polymerase I
DNA polymerase III
adds DNA nucleotides to a growing chain
glues okazaki fragments together
unwinds double-stranded DNA
The lac orperon:
Can only be induced when _____ is present and _____ is absent.
When lactose is NOT present, the lac operon is ______.
When lactose(inducer) is present, it binds to the ____ and induces the lac operon.
When glucose is absent, ____ will bind to ____ (the regulatory protein) that helps RNA polymerase bind to the promoter of the lac operon.
cyclic AMP, CAP(catabolic activator protein)
The tryptophan operon:
The operon is continually turned __1__. Unless __2__ is present.
If __3__ is present, it will bind to the __4__ and block RNA polymerase from transcribing the tryptophan biosynthesis genes.
The enzyme responsible for transcription is called ____.
The purpose of DNA replication is:
to transfer genetic information to the next generation
What are three characteristics about R factors that contribute to the spread of antibiotic resistance?
1. R factors are transferred very rapidly to nonresistant organisms
2. R factors can be transferred between closely related organisms
3. The more frequently antibiotics are used, the quicker the selection for resistant strains
YOU MIGHT ALSO LIKE...
Microbiology: Bacterial Genetics. CH. 8
Ch 7 Microbial Genetics
AP Biology Chapter 16
AP Biology Chapter 9; DNA and Its Role in Heredity…
OTHER SETS BY THIS CREATOR
Chapter 14a Host-Microbe Relationships and Disease…
Chapter 10: Antimicrobial Drugs