molecular biology Flashcards
what are two kinds of nitrogenous bases
purines (A,G)
Pyrimidines (C, T, U)
what was the experiment where they used mice to conduct an experiment about prokaryotic bacterium transformation
Frederick Griffiths Experiment
what was the hypothesis of the Frederick Griffiths experiment
macromeolcule from S bacteria, which functions as the genetic material, will be able to convert type R bacteria into type S
what was the bacteriophage infection experiment called
The Hershey-Chase Experiments
what did they do in the Hershey-Chase Experiments
they fed T2 infected bacteria with radioactive compounds (phosphorus and sulphur) and added them into viral DNA and proteins, respectively
what were the results of the Hershey-Chase Experiments
the virus DNA, not the proteins entered the host bacterial cells
what do nucleotides consist of
a nitrogenous base
a pentose (5 carbon sugar)
a phosphate group
what does a nucleotide structure consist of
phosphate, thymine, deoxyribose
in RNA, what replaces thymine
Uracil
what bonds the sugar-phosphate backbone
phosphodiester bonds
what is the DNA sequence prime
read from the 5’ end to the 3’ end
who discovered that the structure of DNA was a double-stranded helix
James Watson and Francis crick
DNA molecules consist of two strands running in what direction
opposite
how do nitrogenous bases connect in the middle
through H-bonds
t or f RNA is double stranded
false it’s single stranded
what does mRNA do
a transcript of the gene that carries information for the synthesis of proteins
what does tRNA do
translater between nucleic acid and protein by picking up specific amino acids and recognizing the appropriate codons in mRNA
what does rRNA do
most abundant type of RNA
together with proteins forms the structure of ribosomes
how is genetic information coded in the DNA molecule
information must lie on the linear sequence of nitrogenous bases, (arrangement of bases)
How is the information passed on from one cell to the next
because of the complementary base pairing of nitrogenous bases
that one strand serves as a template to form a new strand (DNA replication)
how does the genetic material function
the DNA passes on its information (transcription) used in cell function
what are the three possible mechanisms for DNA replication
semiconservative
conservative
dispersive
what happens during the semiconservative mechanism
DNA replication produces DNA molecules with 1 parent strand and 1 newly made strand
what happens during the conservative mechanism
dna réplication produces 1 double helix with both parental stands, and the other with 2 daughter strands
what happens during dispersive mechanism
segments of new DNA are with the parental DNA
what experiment showed that DNA replication is semi-conservative
meselson and stahl experiment
what is the untwisting of the DNA molecule
breaking H-bonds between N-bases by certain enzymes
what enzyme helps in linking of free nucleotides to form a new strand
DNA polymerase
what end are nucleotides added at
3’
What links DNA pieces
DNA ligase
what is a gene expression
flows of genetic information from the genotype to the phenotype
what is transcription
information encoded in DNA is made into complementary RNA. Said to produce mRNA
what is translation
process of synthesizing a specific polypeptide by using information encoded in the mRNA on a ribosome
in transcription what does the promoter do
site where RNA polymerase binds to begin transcription
in transcription: what does regulatory sequences do
site binding to regulatory proteins control whether a gene is turned on or off
in transcription what is the transcribed region
a region of DNA that is transcribed into an RNA molecule
in transcription what is the terminator
sequence that causes the RNA strand to be released from the transcription complex
