Genetics Exam 2 Flashcards
only DNA transforms
transformation of bacteria
only radio labeled DNA is passed to offspring viruses
Hershey-Chase experiment
composed of deoxyribose sugar, phosphates, and nitrogenous bases
nucleotides
two DNA strands intertwine to form a double helix with base pairing between antiparallel strands
DNA double helix
phosphodiester bonds between nucleotides in DNA backbone
single DNA strand
A and G
Purines
T and C
Pyrimidines
What kind of bonds between bases in complementary DNA strands
hydrogen bonds
Which experiment proved that DNA synthesis is semiconservative
Messelon-Stahl experiments
Catalyzes the synthesis of DNA
DNA polymerase
Synthesizes RNA primers that initiate DNA replication
Primase
Joins DNA strands together by forming phosphodiester bonds
Ligase
adds telomeres to the ends of chromosomes
Telomerase
unzips double-stranded DNA
helicase
unwinds DNA creating temporary breaks in DNA helix
topoisomerase
DNA->RNA->protein
central dogma
DNA->RNA
Transcription
RNA->protein
translation
RNA polymerase synthesizes RNA using what template
DNA
1) Initiation 2) Elongation 3) Termination
Transcription steps
Cap 5’ end with
7-methylguanosine
splice to remove introns and glue-
exons together
a cellular process that allows a single gene to produce multiple mRNA transcripts, which can be translated into different proteins.
alternative splicing
varying amino acid sequences, potentially altering protein domains, sub cellular localization, and interaction capabilities
alternative splicing effect on protein structure and function
RNA transcript (introns) are removed and remaining (exons) are spliced together
mechanism of splicing
basic structure of proteins can consist of how many different amino acids
20
different general amino acid structures
Primary, Secondary, Tertiary, and Quaternary
linear order of amino acids in a protein
Primary structure
arrangement of amino acids that are near each other in a polypeptide (or protein) into alpha helices and beta pleated sheets
Secondary structure
spacial arrangement of amino acids (and secondary structures) that are far apart in the linear sequence
Tertiary structure
spacial arrangement of amino acids (or proteins) that associate with each other to form a multi-subunit molecule
Quaternary structure
in eukaryotes, one gene codes for one protein
one gene-one enzyme hypothesis
nucleotide sequence in DNA or RNA read in three groups called codons, directly correspond to amino acids in proteins
genetic code during translation
three nucleotides in mRNA encode a single amino acid
codon
three nucleotides in tRNA that are complementary to codon in mRNA
Anti-codon
start codon
AUG
stop codons
UAA, UAG, UGA
some amino acids are specifies by more than one codon (UUU and UUC both code for phenylalanine)
degenerate code
catalyzes peptide bond formation
large ribosomal subunit
decodes genetic message on mRNA- matching codons on anti-codons to tRNA molecules
small ribosomal subunit
translate genetic information into proteins
rRNA
links mRNA to amino acids during protein synthesis
tRNA
contain information that directs cells to make proteins
mRNA
tRNA brings amino acid into
A site
anti codon in tRNA pairs with codon in
mRNA
peptide transferase makes a peptide bond between the amino acids in
the P and A sites
uncharged tRNA falls out of the P site and the ribosome moves one codon along the
mRNA
growing polypeptide attached to tRNA are now in
P site
a change in a single nucleotide can change amino acids in a protein or result in a
premature stop codon
can tell about protein structure because it determines protein function- zinc finger motifs bind DNA
X-ray crystallography- used to determine 3D structure of proteins
refers to all proteins in cell, tissue, or organism
proteome
isolate DNA, Cut DNA- 3 types of restriction enzymes, insert target DNA into DNA vector, transform bacteria with vector and isolate individual clones
steps of making and cloning recombinant DNA
isolate mRNA from a specific tissue, then reverse transcribe it into cDNA, and insert cDNA fragments into vectors
how cDNA libraries are made
detects and measures specific DNA sequences in a sample; digesting DNA, separating fragments, transferring fragments, probing, and analyzing
southern blots
detects specific proteins in a sample; separate proteins, transfer proteins, detect proteins, and analyze
western blots
detect and measure amount of RNA in a sample; separate RNA, transfer RNA, hybridize, wash and detect
northern blots
used to study gene expression, site directed mutagenesis, and genetic testing; denaturation, annealing, and extension
PCR
read starting at the bottom; extraction, library preparation, sequencing, and analysis
DNA sequencing
individual base pair substitutions, insertions, or deletions
how site directed mutagenesis is used to dissect gene function in vitro (in cell culture)
two or more identical protein monomers exchange structural elements and fold into dimers or multimers
deletion or exchange (domain swapping) of large DNA segments
cloning viral RNA genomes into bacterial plasmids or artificial chromosome vectors
reverse genetics
a molecular genetics approach that identifies the genetic basis of a phenotype or trait of interest
forward genetics
reating genetically modified organisms (GMOs) where a specific gene of interest is altered or introduced
how recombinant DNA technology is used to study gene function in vivo (in whole organisms)
introduced from species to another
transgenes
substitute a null (nonfunctional) allele for a normal allele
gene knockouts
replacement substitutes a modified allele for a wild type allele
gene replacement
