eating habits - 13th set Flashcards
Genome (genetic…and the exception) ex.
is the cell’s genetic information; mainly composed of DNA . exception is in a group of viruses belonging to RNA family of viruses - they have RNA as the genome instead of DNA. ex. covid, flu, HIV.
Chromosomes (hist)
are thread like structures within cells
- contains DNA and associated protein. in bacterial cells, it includes non-histone protein. in human cells, its histone and non-histone proteins.
Gene (specific - little piece)
is segment of DNA that codes for a specific functional product; many genes forms a genome
Gene expression (transcr. tranlat. dogma)
(includes transcription and translation) and Central Dogma.
translation in humans and bacteria always occurs in the…
cytoplasm.
transcription - bacteria - always occurs in (location)
cytoplasm. in humans, or eukaryotes, it occurs inside the nucleus.
every time a cell divides, 2 things occur - (copy and pass)
1) DNA replication and 2) gene expression in daughter cells
Viruses breaks the rule of central dogma (RNA to…CDM)
some viruses that have RNA genome make cDNA, then they make mRNA, then they make protein. this is reverse transcriptase.
central dogma holds good in biological world except…(retro)
for a group of viruses that belongs to retroviruses. they don’t follow the rule, they encode a reverse transcriptase.
retroviruses includes…(retro alphabet)
some DNA viruses, hep B (DNA virus) C D and E are all RNA.
among RNA viruses - the retroviruses are…
HIV.
reverse transcriptase is exclusively encoded by the…(sick)
viral genome. this means uninfected, normal cells dont have reverse transcriptase
reverse transcriptase is RNA is copied to…
DNA, not the other way around
viruses that are RNA genome can be…(double in Rio)
1) double-strand of RNA, as in reovirus family
2) single-stranded RNA genome
all RNA genome containing viruses….(his fav thing to say)
that code for RNA dependent RNA polymerase (different from DNA dependent RNA polymerase)
DNA inside cells exists as…(DNA inside cleaners)
linear polymer of deoxynucleotides
3 and 5 (strands of DNA) - (highway)
running opposite directions.
strands are in helix like structure (dimmers - Pony and pyramids)
2 strands are anti-parallel (?) A always with T, and G always with the C. purine always with pyrimidins bc it provides stable structure
helix backbone is made of…(mentos backbone)
pentose sugar and phosphate groups
the four bases forms the…(up)
steps of the ladder
base pairing occurs in a specific way
the 2 strands are complimentary
strands are held together by hydrogen bonds between…(baseball)
the bases
DNA structure is susceptible to…(morge)
heat or chemical (treat with urea or formaldyhde) denaturation (melting) melting is just separation of the 2 strands
it’s not the number but the…
sequence of nucleotide is important
DNA is distributed equally between…(me and lane)
DNA replicates after…
the daughter cells - dna replicates after cell division. both daughter cells get equal amount of DNA
DNA replication : 3 steps (spool - H and mom guessed)
a. Unwinding: hydrogen bond breaks
b. Complimentary base pairing
c. Bond formation - hydrogen bond and phosphodiester bond
Replication is semi-conservative
- one strand serves as template for the new strand
- each of the 2 new DNA molecules contains one of the original parental strand
DNA replication is asymmetric - leading and lagging strand (race)
one strand is synthesized at a faster rate (called the leading strand)- 2nd one at a slower rate (lagging strand).
DNA replication is..(bi)
bi-directional
DNA replication is a very…(poly replicate reporter)
accurate process - is due to proof-reading ability of the DNA polymerase
DNA replication requires not ATP, but…(STP)
energy ; fueled by participation of dNTP’s
Replication initiates from…(it’s literally in the question)
the origin of replication
Replication encompasses…(ripley replicates)
collaborative effort of many components:
proteins and non - proteins part, complexed as replisome - replisome is involved in DNA replication
Bacterial DNA is methylated (meth changes genes)
methylation 1. plays role in gene expression - turning on or off gene expression. 2) plays role in DNA replication initiation
DNA polymerase I : (copy strand - prof. ease)
Uses one strand as a template to generate the other strand. has proof reading exonuclease activity. elongates DNA chain only in one direction.
Replication fork (fork in the road)
is where active DNA replication occurs in replication bubble - parental strand are no more paired at the replication fork - get separated
Bacterial Genetics - no…
NO SEXUAL REPRODUCTION IN BACTERIA - yet they evolve
Vertical gene transfer (generations) - what is it, and who is doing it?
also called longitudinal gene transfer. it occurs in all higher plants and animals. genes are passed from one generation to the next.
Horizontal gene transfer -
lateral gene transfer. the genes are transferred from the members of the same generation - occurs in lower forms of life.
Some features of the above (above is horizontal gene transfer) DNA transfer processes: it requires a…
donor and a recipient cell.
Griffith’s Experiment (capsule in cabin)
trying to develop a vaccine against pneumonia. he used s. pneumonia (2 strains) 1 had capsule (the virulent one - pathogenic) and non-capsulated (non-virulent).
Transformation (Dan mediator)
This is horizontal gene transfer. DNA transfer occurs because of competence factor
transformation is possible only when….
the recipient cell is competent. works when donor and recipient cell’s DNA are closely related cells can be made to transform by artificial transformation
electroporation - when the cells are treated for a brief (electroshock)
time (1 ml sec) with high voltage electric current - it momentarily opens up some pores allowing DNA entry into the cells.
transformation - subtle alternations in p.m./ cell wall…(transform at salon)
that permits small pieces of DNA uptake. even a small piece of dna has high molecular weight and can’t diffuse across p.m. or the cell wall in non-competent cells.
Conjugation: complex process (pili)
DNA transfer done through pili; occurs when bacteria are in close contact.
conjugation Differs from transformation in four ways (contact, opposite, large transfer, only one way)
i. contact between donor and recipient cell is necessary
ii. cells must be of opposite mating type - F+ and F-
iii. larger piece and quantity of DNA is transferred
IV. There is polar/directional transfer of DNA = always goes from F+ to F- cells.
Transduction -who mediates and the 2 types (the real conductors - selective)
Transduction: recombining bacteria in which genes from a host cell (a bacterium) are incorporated into the genome of a phages and then carried to another host cell when the bacteriophage initiates another cycle of infection. Are of 2 main types: Generalized transduction and Specialized transduction
bacterial conjugation in e.coli (reassignment - wear it, cure it - plasmid)
F+ (because they have the F plasmid, which codes for sex pili) are male, F- are female. F - turns into F + cell when it acquires the plasmid. curing of plasmid - it throws off the plasmid.
HFR - high frequency of recombination (recombine F)
Just means an F plasmid was integrated into DNA.
F plasmid intact. short, small piece of DNA.
F plasmid is intact bc it didn’t receive the complete F plasmid. conjugation is short, just a small piece of DNA exchanged.
Central dogma is (simple)
linear path of decoding the genetic information. Replication is DNA is copied to RNA
Replication is
DNA is copied to RNA - this is transcription.
Translation is just (pb)
protein synthesis.
retroviruses ex. (blame it on REO - retro)
is respiratory virus, enteric virus, orphan viruses.
RNA genome - single stranded RNA genome (translation) (R+ can be)
can be +RNA or -RNA. RNA + can be immediately translated - it acts as a messenger RNA.
deoxynucleotides - is made of 3 parts (first part in the answer - oxy)
deoxyribose sugar (5 carbon pento sugar), phosphate group, nitrogenous bases (can be pyrimdins or purines) purines include AG - pyridimines are the T.C.
griffith’s experiment - capsule helped…(saved it..capsulated and non-capsulated)
bacteria from being phagocytized. capsulated also called S cells bc they formed smooth colonies on agar plate. no capsulated called R cells because they formed rough colonies.
griffith’s experiment - R cells (R-recognized)
r cells could be easily recognized and phagocyotized and eliminated.
retrovirus has..(80s backward) RIP
protease, reverse transcriptase, and integrase
Herpes virus and human papillomavirus are..
DNA viruses
Influenza, common cold and hepatitis A are…
RNA viruses
Competence factors make…(mostly competent, but..)
subtle changes in membrane including DNA binding protein expression.
Interpretation of Griffith results by Avery, Mc Carty and Mac Leod. (1st - butterfly)
that DNA carries genetics.
DNA is the transforming agent and carries the genetic information, 1st experimental evidence proving DNA is the genetic material
How cells can be artificially transformed? (electrol)
Electroporation
How’s conjugation different from transformation? (jasmine)
Polar transfer ( aka unidirectional transfer ) of genetic material in conjugation from male to female only.
where is Origin of transfer coded? (___plasmid)
the F plasmid codes for the origin of transfer
artificial transformation (artificial milk)
chemical. means - you use cold calcium chloride plus brief heat shock OR electroporation.
conjugation - complex - only one strand is…
transferred to the recipient.
Generalized transduction (general)
no specific portion of the gene is transferred
Specialized transduction (selective for a few)
specific portion and few genes are transferred
difference btwn conjugation and sexual reproduction? (think physio)
In conjugation no gamates are involved, unlike sexual repro.
Translation is just…(pb)
protein synthesis.
Heat shock…(after a burn…open pores)
is followed immediately by cooling in ice - this opens some of the pores in the plasma membrane and cell wall and DNA gets inside. (DNA is in the test tube)
horizontal or above gene transfer (integration)
the donor’s DNA is integrated into the recipient cell’s genome.
horizontal or above gene transfer is NOT a…(very little)
frequent event - occurs at a low frequency
5 is 5th carbon atom…
pento sugar.
3 is 3rd carbon atom…
pento sugar.
DNA polymerase I - 5 and 3 strand can only add…(nucle to nucle)
nucleotide to an existing fragment of nucleic acids
5 is the…
leading strand.
how does horizontal gene transfer occur? (TTC (transform the conjugate)
Occurs in bacteria by several ways: transformation, conjugation and transduction
conjugation complex process - either the plasmid…(both transferred)
or the complete genome can be transferred (this is theoretical. in practical sense, no)
orphans
we know they are present, but we do not know what disease they cause in humans.
competent factor in transformation means…(competent pb)
the proteins that are made when bacterial cells are competent (a physiological state of cell when bacterial cells can pick foreign dna)
There is no competence factor or competent cells in…
conjugation.
griffith’s experiment - provided evidence that…(DNA and R cells)
that DNA is the genetic material. DNA fragments, R cells, still had capsid info. even though the cells were heat killed.
single strand RNA genome - it acts as a…(single message)
messenger RNA. RNA (-) is not a messenger RNA, has to be copied to a positive and then translated
during horizontal gene transfer, only a..(hair transfer)
single stranded region replaces similar position of genes in recipient cells.
in the conjugation complex process, the…(complex requires 2)
the second strand of the transferred plasmid is synthesized in the recipient cell.
transformation
first reported by griffith. when bacteria take up foreign genetic material (naked DNA) from the environment
competent cells
ones that can transform - pick up bacteria.
transformation is..___gene transfer
horizontal
