MOLECULAR DIAGNOSTICS EXAM #1 QUESTIONS AND ANSWERS
3 common parts of a nucleotide - (answer)1) 5 carbon sugar
2) phosphate group
3) nitrogenous base
Purines - (answer)Adenine & Guanine
Pyrimdines - (answer)Cytosine, Uracil, and Thymine
Nucleotide subunits are linked together by - (answer)Phosphodiester bonds
List three structural differences between DNA and RNA - (answer)1) on the sugar: RNA has an OH on the
2' C (ribose). DNA has an H on the 2' C (deoxyribose)
2) Nitrogenous base: RNA uses Uracil instead of Thymine
3) RNA is typically single stranded, DNA is double stranded
What is the overall charge of DNA and where on the structure does it come from? - (answer)Negatively
charged- this is due to the oxygen on the phosphate backbone
What is the difference between the leading and the lagging strand in DNA replication? - (answer)-
Leading strand is the continuous strand that copies in the 5' to 3' direction of the opening double helix
-Lagging strand discontinuosly copies the DNA in the 5' to 3' direction on the stran moving in the
opposite direction of the opening double helix. This generates Okazaki fragments
What enzyme opens up the two strands of DNA? - (answer)helicase
Which direction is a DNA sequence always written - (answer)5'-3' direction. If it was not standardized
this would lead to incorrect interpretation of protein sequences and presentation of sequence data.
,MOLECULAR DIAGNOSTICS EXAM #1 QUESTIONS AND ANSWERS
What is a plasmid, and how does it differ from chromosomal DNA? - (answer)A plasmid is an
extrachromosomal (not extraneous), circular piece of DNA found in bacteria. They cary genes that help
bacteria survive in a wide range on environments.
Write the complimentary sequence:
5' ATTGGCC 3' - (answer)5' GGCCAAT 3'
What is Ethidium Bromide? - (answer)an "intercalating agent"
a flourescent dye that binds DNA
Denaturing agents - (answer)-formamide
- high pH (NaOH)
- High temps
what is a Tm - (answer)temp at which 1/2 the bases dsDNA sample have denatured
Human chromosomes - (answer)46 of them
#1 is biggest
#22 is the smallest
Bacteria chromosome - (answer)only 1
circular and much smaller
DNA replication is - (answer)semiconservative
Topoisomerase - (answer)untwists helix
Ligase - (answer)joins the okazaki fragments
, MOLECULAR DIAGNOSTICS EXAM #1 QUESTIONS AND ANSWERS
For DNA replication you need: in vivo - (answer)1) polymerase
2) DNA template
3) primers
4) dNTPs
For PCR Rxn: in vitro - (answer)1) Taq DNA polymerase
2) DNA template
3) 2 primers
4) dNTPs
5) buffers
PCR is an - (answer)artificial way of doing DNA replication
What is Karyotyping - (answer)looks for large scale chromosomal defects
ex: down syndrome
What is the charge on proteins? - (answer)positive or negative. Because the R group is always different
What is the purpose of southern hybridization? - (answer)to identify a gene/sequence within a mix of
DNA
To DNA sequence, use: - (answer)DNA sequencing
To amplify DNA, use: - (answer)PCR
To preform protein analysis, use: - (answer)Western hybridization
To identify the genes expressed, use: - (answer)northern hybridzation
3 common parts of a nucleotide - (answer)1) 5 carbon sugar
2) phosphate group
3) nitrogenous base
Purines - (answer)Adenine & Guanine
Pyrimdines - (answer)Cytosine, Uracil, and Thymine
Nucleotide subunits are linked together by - (answer)Phosphodiester bonds
List three structural differences between DNA and RNA - (answer)1) on the sugar: RNA has an OH on the
2' C (ribose). DNA has an H on the 2' C (deoxyribose)
2) Nitrogenous base: RNA uses Uracil instead of Thymine
3) RNA is typically single stranded, DNA is double stranded
What is the overall charge of DNA and where on the structure does it come from? - (answer)Negatively
charged- this is due to the oxygen on the phosphate backbone
What is the difference between the leading and the lagging strand in DNA replication? - (answer)-
Leading strand is the continuous strand that copies in the 5' to 3' direction of the opening double helix
-Lagging strand discontinuosly copies the DNA in the 5' to 3' direction on the stran moving in the
opposite direction of the opening double helix. This generates Okazaki fragments
What enzyme opens up the two strands of DNA? - (answer)helicase
Which direction is a DNA sequence always written - (answer)5'-3' direction. If it was not standardized
this would lead to incorrect interpretation of protein sequences and presentation of sequence data.
,MOLECULAR DIAGNOSTICS EXAM #1 QUESTIONS AND ANSWERS
What is a plasmid, and how does it differ from chromosomal DNA? - (answer)A plasmid is an
extrachromosomal (not extraneous), circular piece of DNA found in bacteria. They cary genes that help
bacteria survive in a wide range on environments.
Write the complimentary sequence:
5' ATTGGCC 3' - (answer)5' GGCCAAT 3'
What is Ethidium Bromide? - (answer)an "intercalating agent"
a flourescent dye that binds DNA
Denaturing agents - (answer)-formamide
- high pH (NaOH)
- High temps
what is a Tm - (answer)temp at which 1/2 the bases dsDNA sample have denatured
Human chromosomes - (answer)46 of them
#1 is biggest
#22 is the smallest
Bacteria chromosome - (answer)only 1
circular and much smaller
DNA replication is - (answer)semiconservative
Topoisomerase - (answer)untwists helix
Ligase - (answer)joins the okazaki fragments
, MOLECULAR DIAGNOSTICS EXAM #1 QUESTIONS AND ANSWERS
For DNA replication you need: in vivo - (answer)1) polymerase
2) DNA template
3) primers
4) dNTPs
For PCR Rxn: in vitro - (answer)1) Taq DNA polymerase
2) DNA template
3) 2 primers
4) dNTPs
5) buffers
PCR is an - (answer)artificial way of doing DNA replication
What is Karyotyping - (answer)looks for large scale chromosomal defects
ex: down syndrome
What is the charge on proteins? - (answer)positive or negative. Because the R group is always different
What is the purpose of southern hybridization? - (answer)to identify a gene/sequence within a mix of
DNA
To DNA sequence, use: - (answer)DNA sequencing
To amplify DNA, use: - (answer)PCR
To preform protein analysis, use: - (answer)Western hybridization
To identify the genes expressed, use: - (answer)northern hybridzation
