genetic material Flashcards
what is gene expression
the flow of genetic information from genotype to phenotype
what is the one gene-one enzyme hypothesis
a single gene controlled the synthesis of a single enzyme
what is the translation process synthesizing
a specific polypeptide by using the information encoded in mRNA on ribosomes
what is the process of transcription
information encoded in DNA is made into complementary RNA
segments of _______ transcribe into _______- molecules that can ________ proteins to produce _______. other segments of ______ are copied into ____ molecules called ___________ _____
DNA, RNA, mRNA, DNA, RNA, non-coding RNA
most genes are ______ into mRNA, than the mRNA is _________ into polypeptide
transcribed, and translated
what is the gene expression in prokaryotes
both transcription and translation occur in cytoplasm due to no nucleus
what is the gene expression in eukaryotes
transcription occurs in nucleus, and translation occurs in ribosomes in rough er
what 4 things are genes composed of
promoter, regulatory sequences, transcribed region, and terminator
what is the function of gene
enables segments of DNA to be transcribed into RNA = formation of functional products
what is a promoter
site in DNA where RNA polymerase binds to begin transcription
what are regulatory sequences
binds to regulatory proteins that control whether genes are turned on or off
what is a transcribed region
region of DNA that is transcribed into RNA
what is a terminator
sequence that causes RNA strand to release from transcription complex
what is a gene
organized unit of DNA
what are the characteristics of genetic material
-replication
-storage of information
-expression of that information
-variation by mutation
what are the three essential components of nucleotides
-nitrogen base
-pentose
-phosphate group
what are nucleosides composed of
nitrogen base and a ribose/deoxyribose sugar
what do the polymerization of mononucleotides form
nucleic acid
what form is DNA in
double-stranded helix
what are the three types of RNA
messenger RNA, transfer RNA, and ribosome RNA
what is messenger RNA
transcript of gene carries information (codon sequence) for synthesis of proteins
what is a transfer RNA
functions as an interpreter between nucleic acid and protein language by picking up amino acid and recognizing appropriate codon in mRNA
what is a ribosome RNA
together with proteins forms the structure ribosomes
how is the genetic information coded in the DNA molecule
information must lie on linear sequence of nitrogenous bases
how does the genetic material function
must be that DNA passes on information(transcription)
what experiment confirmed DNA as genetic material
the hershey-chase experiment
what is the hershey-chase experiment
used t2 that infects bacteria, infected bacteria with radioactive compounds, and and virus DNA entered host not proteins
DNA structure
-molecule consists of two strands (antiparrellel)
-backbone of strand is sugar phosphate linked end to end through phosphodiester bonds
-nitrogenous base connect through h-bond
-two strands are twisted
what is the sugar molecule of RNA
ribose
what are the nitrogen bases in RNA
adenine, guanine, cytosine, and uracil
what is the structure of RNA
single strand of polynucleotide that may fold upon itself
what is DNA replication
DNA is duplicationed DNA-DNA
what are the 3 possible mechanisms of DNA replication
-semiconservative mechanism
-conservative mechanism
-dispersive mechanisms
what is semiconservative mechanism
DNA replication produces DNA molecules with one parental strand and 1 newly made strand
what is conservative mechanism
DNA replication produces 1 double helix with both parental strands, and the other with 2 daughter strands
what is dispersive mechanism
DNA replication produces DNA strands in which segments of new DNA are with parental DNA
what is the meselson and stahl experiment
showed that DNA replication is semi conservative
what is the semi-conservation replication molecular processes
-untwisting of DNA moles (breaking h-bonds)
-stands severes as template
-DNA polymerase helps link free nucleotides to form new strand
–nucleotides added at 3’-end
-template(old) and complementary(new) are anitparellel
-DNA pieces are linked by enzyme called DNA ligase
DNA molecular processes with involvement of what major proteins
-replication fork
-leading strand template
-lagging strand template
-leading strand
lagging strand
-topoisomerase
-dna primase
-single stranded binding protein
-DNA clamp
-okazaki fragment
-DNA polymerase
what is the enzyme helicase responsible for
unwinds DNA helix
what is the enzyme primase responsible for
assembles RNA primers in 5’-3’ direction to initiate new DNA strand
what is the enzyme single-stranded binding protein responsible for
stabilize single stranded DNA and prevent the two strands at the replication fork from reforming
what is DNA polermerase 3 responsible for
main replication enzyme in e-coli, extends that RNA primer by adding DNA nucleotides
what is topoisomerase
avoid twisting of DNA ahead of replication fork
what is DNA polymerase responsible for
removes RNA and replaces in with DNA nucleotides
what is the responsibility of sliding clamp
tethers DNA polymerase3 to DNA template making replication more efficient
what is the responsibility of DNA ligase
seals nick left between adjacent bases after RNA primers replaced with DNA
what is the molecular process of transcription
-initiation of transcription requires transcription factors binding to promoter region
-tf recruits RNA polymerase binding to promoter region
-unwinding DNA
-only one strand acts as template
-transcription ends at termination site
transcription stages
transcription initiation, transcription elongation, and transcription termination
