Analyzing Cell, Molecules, and Systems 2 Flashcards
How many genes do humans have?
26,000
There are 1 in ____ nucleotide differences between two human genomes
1,000
What can SNP variants be?
neutral, pathogenic or predisposing
What are SNPs?
single nucleotide polymorphisms
What do endonucleases do?
cut DNA at specific sites
In agarose gel electrophoresis, it differs from SDS page because _____
DNA is already charged
What does ligase do?
glue DNA together
What do plasmids do?
various functions, such as carry and replicate manipulated gene products
What is a DNA library?
Every gene in the human body can be stored in bacteria indefinitely and propagated at anytime
What is a cDNA clone?
DNA copy of mRNA, n introns and much smaller than original gene, requires viral enzyme
Genes vs gene products
Genes: whole genome, intron and exon
Gene products: no introns, just coding DNA
What does polymerase chain reaction (PCR) do?
amplify isolated DNA regions
What is the purpose of PCR?
- earlier detection of microorganisms: HIV, bacterial and fungal infections
- detection fo specific genetic mutations
What is the process of PCR?
ds DNA obtained
denatured to ss DNA
primers complement sequences that flank each end of DNA in 3-5’ direction
primers anneal
add deoxy nucleotide triphosphate (dNTPs) - all 4
Taq polymerase synthesizes copy of DNA by extending the primers on both ends, DNA doubles in each cycle
What are the advantages to PCR?
very small amount of template DNA needed. 10^9 fold amplification from trace amounts of DNA
What are the disadvantages to PCR?
need to know the sequence of the flanking DNA for primer design, error prone, amplification of contaminating DNA
What is quantitative PCR (qPCR)?
used to quantify copy number of a specific gene in two or more samples in real time
What does qPCR have along with primers?
a probe which fluoresces only in presence of the PCR product
What is qPCR used for?
detect levels of infectious agent
determine levels of gene expression
What are detections of variation in DNA sequences used for?
forensics
diagnostics (newborn screening, genetic carriers, etc)
What is restriction fragment length polymorphism (RFLP)?
When difference in genome occurs in recognition sequences for restriction enzymes, the pattern on the gel is different
DNA fingerprinting
What are variable number of tandem repeats (VNTR)?
pattern of short tandem repeats occurs in genome but varies in individuals
VNTR isolate from genomic samples by flanking restriction sites or through PCR
useful in identification and severity of inherited diseases
What are DNA microarrays used for?
determine overall change in gene expression between two samples
