BIOL 3110 Test 1 Questions and Verified
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DNA - Correct Answers ✅deoxyribonucleic acid
polymer of nucleotides, aka - Correct Answers ✅DNA
A nucleotide consists of - Correct Answers ✅phosphate
group, pentose sugar, nitrogenous base
what are 2 major diff btw purine and pyrimidine? - Correct
Answers ✅1) purine is larger bc it has 2 infused C rings
2) purine = AG
pyrimidine = CUT
nucleosides are:_____________________________, attached by
__________________ bonds. they can have either syn or anti
conformations but are more sterically favourable in the ____
position. - Correct Answers ✅sugars + nitrogenous bases
attached by B-glycosidic bonds, anti. (Lec 1, Fig 1)
furanose ring - Correct Answers ✅5 member ring with 4 C
and 1 O
phosphate groups attach to the C-5' position of nucleosides
to form nucleotides through what type of bond?
,BIOL 3110 Test 1 Questions and Verified
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phosphate groups at C-5' position attach to OH groups at C-3'
position to link nucleotides thru what type of bond? - Correct
Answers ✅phosphoester bond, phosphodiester bond
what are Chargaff's 2 rules? - Correct Answers ✅1) there is
variability in DNA from one species to another
2) there is equal amounts of pyrimidine and purine in DNA
why were watson and crick incorrect when stating that like
bases paired eg. A-A - Correct Answers ✅dna has a
constant width. pairing purines together (which are larger
than pyrimidines), and then pairing 2 pyrimidines (smaller)
wouldn't result in a constant width. Thus purines pair with
pyrimidines (Lec 1 - Fig 2)
each helix of DNA has major and minor grooves. What is their
purpose? - Correct Answers ✅-they allow small proteins to
bind to the dna w/o disrupting the double helix
-help regulate transcription or replication
what're 2 diff btw major and minor groves? - Correct
Answers ✅1)major groove is rich in chemical information
whereas the minor groove is not
,BIOL 3110 Test 1 Questions and Verified
Answers, 100% Score Guarantee Pass
(Latest 2025)
2)major grooves are larger (2.2 nm compared to 1.2 nm
minor)
-thus major grooves allow for insertion of large proteins, such
as aa side chains, whereas minor grooves don't
what're the 3 forms of DNA helices? explain their differences.
which are right-handed helices & which are left-handed
helices? where are they usually found? (Lec 1 - Fig 7) -
Correct Answers ✅1)A-form
-shorter & wider, thus bases are closer together + it's harder
to distinguish major and minor groves
-found in less hydrates conditions
-has a hole in centre bc BP are not interacting perfectly
-right-handed helix
2)B-form
-is dna found under physiological conditions/normal
conditions
-very ordered structure
-right-handed helix
3)Z-form
-narrow & longer, thus bases are further apart
, BIOL 3110 Test 1 Questions and Verified
Answers, 100% Score Guarantee Pass
(Latest 2025)
-zig-zag pattern
-only found in prokaryotes
-left-handed helix
how are the 2 strands of dna kept close to one another
despite the electrostatic repulsion (ie. neg charged phosphate
groups)? - Correct Answers ✅-h-bonding btw base pairs
and base stacking keeps the strands together
-these effects are stronger than the repulsion effects
what is responsible for the specificity of base pairing? -
Correct Answers ✅h-bonding bc A-T have 2 H-bonds and G-
C have 3
ss DNA absorbs 30-40% more UV light than ds DNA. why?
(Lec 1 - Fig 3) - Correct Answers ✅-ssDNA have exposed
nitrogenous bases which are able to absorb UV light, dsDNA
has base stacking which hides the bases
Hyperchromic shift - Correct Answers ✅the increase in UV
absorption of heated dsDNA in solution(Lec 1 - Fig 4)
what does the midpoint of the hyperchromic shift (aka
melting temperature/Tm) show? - Correct Answers ✅shows
the temp at which 50% of the ds DNA has melted
Answers, 100% Score Guarantee Pass
(Latest 2025)
DNA - Correct Answers ✅deoxyribonucleic acid
polymer of nucleotides, aka - Correct Answers ✅DNA
A nucleotide consists of - Correct Answers ✅phosphate
group, pentose sugar, nitrogenous base
what are 2 major diff btw purine and pyrimidine? - Correct
Answers ✅1) purine is larger bc it has 2 infused C rings
2) purine = AG
pyrimidine = CUT
nucleosides are:_____________________________, attached by
__________________ bonds. they can have either syn or anti
conformations but are more sterically favourable in the ____
position. - Correct Answers ✅sugars + nitrogenous bases
attached by B-glycosidic bonds, anti. (Lec 1, Fig 1)
furanose ring - Correct Answers ✅5 member ring with 4 C
and 1 O
phosphate groups attach to the C-5' position of nucleosides
to form nucleotides through what type of bond?
,BIOL 3110 Test 1 Questions and Verified
Answers, 100% Score Guarantee Pass
(Latest 2025)
phosphate groups at C-5' position attach to OH groups at C-3'
position to link nucleotides thru what type of bond? - Correct
Answers ✅phosphoester bond, phosphodiester bond
what are Chargaff's 2 rules? - Correct Answers ✅1) there is
variability in DNA from one species to another
2) there is equal amounts of pyrimidine and purine in DNA
why were watson and crick incorrect when stating that like
bases paired eg. A-A - Correct Answers ✅dna has a
constant width. pairing purines together (which are larger
than pyrimidines), and then pairing 2 pyrimidines (smaller)
wouldn't result in a constant width. Thus purines pair with
pyrimidines (Lec 1 - Fig 2)
each helix of DNA has major and minor grooves. What is their
purpose? - Correct Answers ✅-they allow small proteins to
bind to the dna w/o disrupting the double helix
-help regulate transcription or replication
what're 2 diff btw major and minor groves? - Correct
Answers ✅1)major groove is rich in chemical information
whereas the minor groove is not
,BIOL 3110 Test 1 Questions and Verified
Answers, 100% Score Guarantee Pass
(Latest 2025)
2)major grooves are larger (2.2 nm compared to 1.2 nm
minor)
-thus major grooves allow for insertion of large proteins, such
as aa side chains, whereas minor grooves don't
what're the 3 forms of DNA helices? explain their differences.
which are right-handed helices & which are left-handed
helices? where are they usually found? (Lec 1 - Fig 7) -
Correct Answers ✅1)A-form
-shorter & wider, thus bases are closer together + it's harder
to distinguish major and minor groves
-found in less hydrates conditions
-has a hole in centre bc BP are not interacting perfectly
-right-handed helix
2)B-form
-is dna found under physiological conditions/normal
conditions
-very ordered structure
-right-handed helix
3)Z-form
-narrow & longer, thus bases are further apart
, BIOL 3110 Test 1 Questions and Verified
Answers, 100% Score Guarantee Pass
(Latest 2025)
-zig-zag pattern
-only found in prokaryotes
-left-handed helix
how are the 2 strands of dna kept close to one another
despite the electrostatic repulsion (ie. neg charged phosphate
groups)? - Correct Answers ✅-h-bonding btw base pairs
and base stacking keeps the strands together
-these effects are stronger than the repulsion effects
what is responsible for the specificity of base pairing? -
Correct Answers ✅h-bonding bc A-T have 2 H-bonds and G-
C have 3
ss DNA absorbs 30-40% more UV light than ds DNA. why?
(Lec 1 - Fig 3) - Correct Answers ✅-ssDNA have exposed
nitrogenous bases which are able to absorb UV light, dsDNA
has base stacking which hides the bases
Hyperchromic shift - Correct Answers ✅the increase in UV
absorption of heated dsDNA in solution(Lec 1 - Fig 4)
what does the midpoint of the hyperchromic shift (aka
melting temperature/Tm) show? - Correct Answers ✅shows
the temp at which 50% of the ds DNA has melted
