Ch 7 Microbial Genetics
Base pairs (BP)
-A complementary arrangement of nucleotides in a strand of DNA or RNA
chromosomes
-A molecule of DNA associated with protein and RNA -Main portion of DNA are packaged in 1-2 distinct chromosomes
How is the base pairing in DNA?
-Adenine (A) bonds with thymine (T) -Guanine (G) bonds with cytosine (C)
nucleosomes
-Bead of DNA bound to histone in eukaryotic chromosomes
what are the functions of nucleotides?
-Building block of DNA/RNA -Energy (Nucleotide Triphosphates (ATP))
Bacteriocin plasmid
-Carry genes for proteinacceous toxins called bacteriocins -compound, made by bacteria, kills neighboring bacteria (which lack this plasmid) -Allow bacteria to be able to compete with more bacterias, so they can have more nutrients
Resistance plasmid
-Carry genes for resistance to one or more antimicrobial drugs or heavy metals -allow bacteria resist antibiotics -Bacteria that does not have it respond to antibiotic
Fertility plasmid
-Carry instructions for conjugation -allows bacteria to build pilus or pilli to perform conjugation -Also called F-plasmid, F-Factor, F+ -Always connect pillus with F- bacteria (which does not have fertility plasmid)
Describe the shape of plasmids
-Circular -smaller than chromosomes
Eukaryotic chromosomes are composed of_
-DNA -globular eukaryotic histones, which DNA is wrapped around them
What is the sugar in DNA? what is the sugar in RNA?
-DNA has deoxyribose sugar -RNA has ribose sugar
what does unzips DNA in DNA replication? How? What does this action form? what interaction it has with the strand?
-DNA helicase unzips the double helix - by breaking hydrogen bonds between complementary base pairs (unwinds the double helix) -to form a replication fork. -physical interaction
how plasmid replication is performed in relation with chromosomes?
-Do not link together with the replication of bacterial chromosomes -Do not happen at the same time of chromosome replication -Multiple copies of the same plasmid are found within porkaryotic cells -Plasmids reproduce all the time (not before asexual reproduction as chromosomes) -They have things that help them to replicate more frequently than chromosomes -They have their own information to replicate
what are some of the advantages that plasmids offer? (examples)
-Fertility -Resistance -Bacteriocin -Virulence
what is the difference between the shape, location, and the way is packed DNA in eukaryotes and prokaryotes?
-In prokaryotes, it is circle shape and it is winded to keep it in a compact way around proteins and RNA->into a ball/ They are found in the nucleoid -Linear chomosome is found in eukaryotes around histones within nucleus
what are some of the aspects that Geneticists study?
-Inheritance -Physical structure and function of genetic material -Mutations -The transfer of genetic material among organisms
where is the extranuclear DNA in eukaryotes? which shape DNA have?
-Mitochondria -Chloroplast -circular shape as prokaryotes -Plasmids (some fungi and protozoa have)
Plasmids function
-Not essential for normal bacterial metabolism, growth, or reproduction -Can confer survival advantages -give specific characteristics to bacteria
Describe the ends of a DNA molecule
-One end of a DNA strand is called the 5' end because it terminates in a phosphate group attached to a 5' carbon -the opposite end of the strand is called the 3' end because it terminates with a hydroxyl group bound to a 3' carbon of deoxyribose.
what are nucleotides composed of?
-Phosphate Group -Nitrogenous Bases (A, G, C, T/U) -Pentose sugar (Deoxyribose, Ribose)
What does prokaryotes use as their genetic material? what does eukaryotes use as their genetic material? what does viruses use as their genetic material?
-Prokaryotic and eukaryotic cells use DNA as their genetic material -some viruses use DNA, and other viruses use RNA.
Prokaryotic cells have how many chromosomes? what is the term used for this?
-Prokaryotic cells have a single copy of each chromosome -haploid
What are the two major classes of nucleic acids?
-RNA -DNA
Nucleoid
-Region of prokaryotic cytosol containing the cell's chromosome(s) -It has no membrane
Plasmid
-Small molecules of DNA that replicate (make copies of itself) independently -Carry information required for their own replication, and often for one or more cellular traits
what distinguishes one nucleic acid from other? (within the same categories like distinguish between DNA and an other DNA molecule)
-The length (how many nucleotides are linked together) and sequence of nucleotides (the organization of the nucleotide bases)
antiparallel in DNA
-The two strands are oriented in opposite directions to each other (interact in an opposite direction) -One strand runs in a 3' to 5' direction, while the other runs in a 5' to 3' direction
Why DNA needs to be copied?
-To perform asexual reproduction (make sure DNA goes to daughter cells) -replicate prior asexual reproduction
How are chromosomes in prokaryotes?
-Typically circular and localized in the region of the cytosol called the nucleioid
DNA contains_. In which organisms DNA is found?
-all the information that organism needs to survive -In all organisms
DNA structure is_
-anti-parallel double helix held together by hydrogen bonding between bases -has polarity
What are genes composed of? What does this parts code for?
-are composed of specific sequences of nucleotides that code for polypeptides or RNA molecules.
what are the 4 main macromolecules?
-carbohydrates -proteins -lipids or fats -nucleic acids
Virulence plasmids
-carry instructions for structures, enzymes, and toxins that enable a bacterium to become pathogenic -Related to pathogens (make sick) -measure of how sick can make us -Factors (plasmids) needed to cause diseases -If bacteria have this plasmid, have some cellular trait that allow to make us sick -Create capsule, toxin, digestive enzyme
The haploid genome of a prokaryotic cell consists of_
-chromosomal DNA (single and circular shape) -Extrachromosomal DNA (Plasmids)
DNA exists as_. why?
-chromosomes (DNA wind around proteins) -DNA is packed in a way that is easier to keep inside of the cells -If need DNA unwind it, then wind again after used it
describe prokaryotic chromosomes. Where are they localized within the prokarytic cell?
-circular molecules of DNA associated with protein and RNA molecules -localized in a region of the cytoplasm called the nucleoid.
what plasmids contain? (give examples)
-contain genes that regulate nonessential life functions -Such as: bacterial conjugation; resistance to one or more antimicrobial drugs, heavy metals, or toxins; destruction of competing bacteria; and pathogenicity.
polarity
-directionality -antiparallel -something different at each of the ends of each strand -Used to label
RNA structure
-exists in single strand -has U nucleotide instead of T (DNA) -has ribose sugar -it has polarity
Typically how many chromosomes does eukaryotic cells have? what is the term given to this?
-have more than one nuclear chromosome in their genomes -diploid (two copies of each chromosome)
In addition to DNA, eukaryotic chromosomes contain proteins called_arranged as_, which are_
-histones -nucleosomes -(beds of DNA) ) that clump with other proteins to form chromatin fibers
Genome (describe also what it includes)
-is the sum of all the genetic material in a cell or virus. -the entire genetic complement of an organism; includes its genes and nucleotide sequences
What are the name of the two strands that are formed in DNA replication?
-lagging strand -leading strand
DNA is composed solely of_, whereas RNA is composed of_
-molecules of deoxyribonucleic acid (DNA) -ribonucleic acid
What are the two major characteristics of anabolism?
-start with small molecules and build big molecules -requires energy
what direction does lagging strand is synthesized?
-strand is synthesized in a direction away from the replication fork in fragmented strands that are synthesized in a 5'->3' direction (toward origin of replication)
Deoxyribonucleotides are linked through their_and_to form_(shape)
-sugars -phopshates -two backbones of a helical, double-stranded DNA molecule
Prokaryote genomes consist of_
1-2 chromosomes
how many chromosomes does bacteria have?
1-2 chromosomes but usually they have only one
Can bacteria live without plasmids?
Bacteria can live without plasmids, but if bacteria have they have more benefits by having them
How are chromosomes in eukaryotes?
Chromosomes are threadlike and are most visible during mitosis and meiosis
Define "nitrogenous bases"
Nitrogenous=has nitrogen base: has acid
Phosphodiester bond is what type of bond? hydrogen bond is what type of bond?
Phosphodiester is a covalent bond (strong) Hydrogen bond is a weak interaction or bond (weak interaction)
When are plasmids activated?
Plasmids are activated when they are needed, like the formation of endospores
How the length of DNA is measured?
The lengths of DNA molecules are expressed in base pairs.
what does DNA nucleotides contain?
The nucleotides in DNA contain deoxyribose and A, G, C, and T.
what does RNA nucleotides contain?
The nucleotides in RNA contain ribose and A, G, C, and U
DNA replication is conservative, semiconservative, no conservative? explain why
The process is semiconservative because each daughter DNA molecule is composed of one original strand and one new strand.
How the strands are oriented in relation with each other? (describe them in terms of 5' end and 3' end)
The two strands are oriented in opposite directions to each other: One strand runs in a 3' to 5' direction, whereas the other runs in a 5' to 3' direction
_is the process of by which DNA is copied a. Replication b. Transcription c. Translation d. Mutation e. Recombination
a. replication
The synthesis of RNA from a DNA template is called_ a. Replication b. Transcription c. Translation d. Mutation e. Recombination
b. transcription
Phosphodiester bonds are found between_
between 5' phosphate group and 3' hydroxyl group of another nucleotide
phosphodiester bonds
bonds that are found between nucleotides to form nucleic acids (DNA and RNA)
Eukaryotic genomes consist of_
both nuclear and extranuclear DNA
How the two strands of DNA are held together?
by base-pairs of nucleotides bases connected by hydrogen bonds
How nucleic acids are formed?
by linking nucleotides together by phosphodiester bonds.
What are the two principal genomic structures within prokaryotes?
chromosomes plasmids
what else does eukaryotic cells have? (genetic information) where are they located within the cell?
extrachromosomal DNA in mitochondria, chloroplasts, and plasmids.
plasmids are also called_
factors
what are the bonds found between the base pairs?
hydrogen bonds
The two strands of DNA are held by_
hydrogen bonds between complementary bases of nucleic acids called base pairs (BP)
what does antibiotics do?
inhibits protein synthesis and ribosomes
Genetics
is the study of inheritance and inheritable traits as expressed in an organism's genetic material
what directions does leading strand is synthesized?
it is synthesized toward the replication fork. (5'->3')
DNA in chromosomes function is within_ (in bacteria)
normal bacterial metabolism
nucleic acids are polymers of_
nucleotides
what are the small building blocks of DNA and RNA? (general term)
nucleotides
what other genetic material or extrachromosomal DNA molecules can prokaryotes have?
plasmids
conjugation
process involved in transferring genes from one bacterial cell to another
how are nucleic acids form? (basic process and explain it in terms of catabolic or anabolic)
taking small parts (nucleotides) to putting them together to form a large molecule (anabolic reactions)
DNA synthesis or replication always moves in_
the 5' to 3' direction
Before DNA replication, what happens?
the cell removes histones and other proteins from the DNA molecule
In which organisms does plasmids are found?
they are found only in prokaryotes
how the two DNA strands interact?
through their nucleotide bases
What are the four main types of plasmids?
• Fertility factor • Resistance factor • Bacteriocin factor • Virulence factor
how many hydrogen bonds are found between Guanine and cytosine?
3 hydrogen bonds
5' end will be opposite to the _ in the same chain
3' end
How many base pairs are found in Human genome?
6 billion base pairs in 46 nuclear DNA molecules -Numerous copies of a unique mitochondrial DNA molecule
DNA replication is a simple concept:
A cell separates the two original strands and uses each as a template for the synthesis of a new complementary strand.
what encodes genetic information?
Linear sequence of nucleotides
How the structure of DNA explains its ability to act as genetic material?
1. The linear sequence of nucleotides carries the instructions for the synthesis polypeptides and RNA molecules 2. The complementary structure of two strands allows a cell to make exact copies to pass to its progeny
what are the differences between RNA and DNA?
1. nucleotides in DNA (A,T,G,C) are different from nucleotides in RNA (A,U,G,C) 2. Type of sugar in DNA (deoxyribose) and RNA (ribose)
genes
A specific sequence of nucleotides that codes for a polypeptide or an RNA molecule
How ATP fits within DNA and RNA?
ATP is a building block for nucleic acids
chromatin fibers
An association of nucleosomes and proteins found within the chromosomes of eukaryotic cells
how many hydrogen bonds are found between adenine and thymine (DNA) and adenine and uracil (RNA)?
two hydrogen bonds
what is the function of chromosomes?
way to store and organize DNA in organisms
Haploid (define and tell the type of cell that has it)
• A nucleus with a single copy of each chromosome -1 copy of 1 chromosome • Prokaryotes
Diploid (define and tell the type of cell that has it)
• A nucleus with two copies of each chromosome -2 copies of the same chromosome -Eukaryotes
