molecular Bio Flashcards
central dogma
genetic material is transcribed into RNA and then translated into protein
Frederick Griffith
bacterial transformation
smooth strains with capsule vs rough strains without capsule
Avery, MacLeod, and McCarthy
used purification methods to reveal that DNA is the genetic material
Crick and watson
double helix DNA stucture
Rosaline Franklin
X-ray results showed shape of chromosome
Erwin Chargaff
A=T, G=C
number of units are the same
relative amounts of A, T, G, C bases varies from one species to another
Structure of a nucleic acid
polymer consisted of a chain of nucleotide that contain phosphate, sugar and nitrogenous base
Nitrogenous base
Purine (double ring): Adenine & Guanine
Pyrimidine (single ring): Cytosine & Thymine, Uracil in RNA
Transcription
Produces RNA copy or transcript of gene. Structural genes produce mRNA for amino acid sequence of a polypeptide
Translation
process of synthesizing specific polypeptide on a ribosome
what is a genome?
all of a living think’s genetic material.
chromosome, gene, DNA, mitochondrial DNA, plasmids, plastids
plasmid
small, circular ds DNA that is distinct from a cell’s chromosomal DNA and can replicate independently
plastid
a major double-membrane organelle found in plants and algae. site of manufacture and storage of important chemical compounds used by the cell
DNA hybridization/southern blotting
detection of a specific DNA sequence from DNA samples
RNA hybridization/ northern blotting
to study gene expression by detection of RNA or isolated mRNA in a sample
western blotting
to identify specific proteins from a complex mixture of proteins extracted from cells or an organ
PCR- polymerase chain reaction
amplify specific DNA fragments from genomic DNA
Components of PCR Reaction
template DNA,
oligonucleotide primers (complementary ss DNA),
DNTP (deoxynucleotides- A,T,G,C),
tag polymerase (a very thermostable polymerase),
correct conditions (eg buffers)
RT-PCR (reverse transcription) one-step
combines first strand cDNA synthesis reaction and PCR reaction in same tube,
simplifies reaction setup and reduces possibility of contamination
RT-PCR (reverse transcription) two-step
CDNA is transferred to a separate tube for PCR step.
Detects multiple messages from a single RNA sample, greater flexibility when choosing primers and polymerase
Real time PCR- quantitative PCR
monitors amplification of a targeted DNA molecule during PCR instead of at the end.
used sequence-specific DNA probes that are fluorescent labeled that flashed after hybridization between the probe and its complementary sequence. counts each flash
origin of replication
site of start point for replication
leading strand
forms one long continuous molecule
lagging strand
makes okazaki fragments that have to be connected later
