BMSC 200 Module 10 Exam Questions
and Answers
Nomenclature of nucleosides and nucleotides - ANSWER--Which nitrogenous base
is present (base name)
-Whether he sugar is ribose or deoxyribose (deoxy prefix)
-Whether there are phosphoryl groups
-An alternate method for naming nucleotides is so specify the number and position of
the phosphoryl groups
Suffix of nucleosides - ANSWER--Osine
Suffix for nucleotides - ANSWER--Ylate
Energy transfer - ANSWER--Anhydride linkages in ATP are high energy bonds
-The energy release from hydrolysis of these bonds drives many biochemical
reactions
Signal Transduction - ANSWER--Cyclic AMP, formed from ATP in a reaction
catalyzed by adenylyl cyclase
-Common intracellular messenger produced in response to hormones
Phosphodiester bonds join nucleotides in nucleic acids - ANSWER--Nucleotides
form linear nucleic strands through 3'-5' phosphodiester linkages
-3'-5' phosphodiester bonds are identical in DNA and RNA
-3'-5' phosphodiester linkages are identical, independent of the nucleotides being
joined
-The strand of sugars linked by phosphodiester bridges is called the backbone of
nucleic acid
Sequence information within nucleic acids - ANSWER--It is the sequence of bases
that uniquely characterizes a nucleic acid
-Nucleic acid strands have a direction and their sequences are presented 5'--> 3'
-Sequences of bases is a form of linear information
RNA differs from DNA in that - ANSWER--RNA contains ribose rather than
deoxyribose
-RNA is single stranded but can adopt complex 3D structures
Ribosomal RNA - ANSWER--An integral part of ribosomes ~80% of RNA in cells
Transfer RNA - ANSWER--Carry activated amino acids to ribosomes for protein
synthesis (small molecules 73-95 nucleotides long)
, Messenger RNA - ANSWER--Code for proteins; contains triplet codons that specify
the amino acid sequence of a protein
Micro RNA - ANSWER--Are short oligonucleotides (22-24 nts in length) that function
in transcriptional and post-transcriptional regulation of gene expression
Discovering the double helix - ANSWER--James Watson and Francis Crick
postulated the double helix structure of DNA in 1953
- This model explained all the known experimental data and predicted the
mechanism for storing and replicating the genetic information
-Rosalind Franklin and Maurice Wilkins obtained the X-ray diffraction data that
showed that DNA is a helix
-Their efforts set the stage for Watson and Crick
-Watson, Crick, and Wilson shared the 1962 Nobel prize
Bases of the double helix - ANSWER--Two helical DNA strands coiled around a
common axis forming a right-handed double helix
-The strands run in opposite directions
-The strands are complimentary to each other
-Sugar-phosphate backbones are on the outside of the helix, nitrogenous bases on
the inside
-Base pairs are perpendicular to helix
-Watson-Crick base pairing matches a purine with a pyrimidine to give a constant
helix diameter
Base pairing in the double helix - ANSWER--Adenine base pairs with Thymine
-Guanine base pairs with Cytosine
-The specificity of Watson-Crick base pairing is largely determined by the hydrogen
bonding groups of the nitrogenous bases
-Chargaff's rules: A+G = T+C
-Number of purine equals the number of pyrimidines in duplex DNA
-The A-T and G-C hydrogen bonded pairs are planar and have the same dimensions
Hydrophobic effects - ANSWER--Burying purine and pyrimidine rings in the interior
Stacking interactions - ANSWER--Stacked base pairs form van der waals contacts
Hydrogen bonds - ANSWER--Hydrogen bonding between base pairs
Charge- charge interactions - ANSWER--Electrostatic repulsion of negatively
charged phosphate groups is decreased by cations and cationic proteins
Major and minor grooves - ANSWER--Many proteins bind DNA in a sequence-
specific fashion (restriction enzymes, transcription)
-A double helix has two grooves of unequal width; major groove and minor groove
-Within each groove base pairs are exposed and are accessible to interactions with
other molecules
-DNA-binding proteins can use these interactions to read a specific sequence
and Answers
Nomenclature of nucleosides and nucleotides - ANSWER--Which nitrogenous base
is present (base name)
-Whether he sugar is ribose or deoxyribose (deoxy prefix)
-Whether there are phosphoryl groups
-An alternate method for naming nucleotides is so specify the number and position of
the phosphoryl groups
Suffix of nucleosides - ANSWER--Osine
Suffix for nucleotides - ANSWER--Ylate
Energy transfer - ANSWER--Anhydride linkages in ATP are high energy bonds
-The energy release from hydrolysis of these bonds drives many biochemical
reactions
Signal Transduction - ANSWER--Cyclic AMP, formed from ATP in a reaction
catalyzed by adenylyl cyclase
-Common intracellular messenger produced in response to hormones
Phosphodiester bonds join nucleotides in nucleic acids - ANSWER--Nucleotides
form linear nucleic strands through 3'-5' phosphodiester linkages
-3'-5' phosphodiester bonds are identical in DNA and RNA
-3'-5' phosphodiester linkages are identical, independent of the nucleotides being
joined
-The strand of sugars linked by phosphodiester bridges is called the backbone of
nucleic acid
Sequence information within nucleic acids - ANSWER--It is the sequence of bases
that uniquely characterizes a nucleic acid
-Nucleic acid strands have a direction and their sequences are presented 5'--> 3'
-Sequences of bases is a form of linear information
RNA differs from DNA in that - ANSWER--RNA contains ribose rather than
deoxyribose
-RNA is single stranded but can adopt complex 3D structures
Ribosomal RNA - ANSWER--An integral part of ribosomes ~80% of RNA in cells
Transfer RNA - ANSWER--Carry activated amino acids to ribosomes for protein
synthesis (small molecules 73-95 nucleotides long)
, Messenger RNA - ANSWER--Code for proteins; contains triplet codons that specify
the amino acid sequence of a protein
Micro RNA - ANSWER--Are short oligonucleotides (22-24 nts in length) that function
in transcriptional and post-transcriptional regulation of gene expression
Discovering the double helix - ANSWER--James Watson and Francis Crick
postulated the double helix structure of DNA in 1953
- This model explained all the known experimental data and predicted the
mechanism for storing and replicating the genetic information
-Rosalind Franklin and Maurice Wilkins obtained the X-ray diffraction data that
showed that DNA is a helix
-Their efforts set the stage for Watson and Crick
-Watson, Crick, and Wilson shared the 1962 Nobel prize
Bases of the double helix - ANSWER--Two helical DNA strands coiled around a
common axis forming a right-handed double helix
-The strands run in opposite directions
-The strands are complimentary to each other
-Sugar-phosphate backbones are on the outside of the helix, nitrogenous bases on
the inside
-Base pairs are perpendicular to helix
-Watson-Crick base pairing matches a purine with a pyrimidine to give a constant
helix diameter
Base pairing in the double helix - ANSWER--Adenine base pairs with Thymine
-Guanine base pairs with Cytosine
-The specificity of Watson-Crick base pairing is largely determined by the hydrogen
bonding groups of the nitrogenous bases
-Chargaff's rules: A+G = T+C
-Number of purine equals the number of pyrimidines in duplex DNA
-The A-T and G-C hydrogen bonded pairs are planar and have the same dimensions
Hydrophobic effects - ANSWER--Burying purine and pyrimidine rings in the interior
Stacking interactions - ANSWER--Stacked base pairs form van der waals contacts
Hydrogen bonds - ANSWER--Hydrogen bonding between base pairs
Charge- charge interactions - ANSWER--Electrostatic repulsion of negatively
charged phosphate groups is decreased by cations and cationic proteins
Major and minor grooves - ANSWER--Many proteins bind DNA in a sequence-
specific fashion (restriction enzymes, transcription)
-A double helix has two grooves of unequal width; major groove and minor groove
-Within each groove base pairs are exposed and are accessible to interactions with
other molecules
-DNA-binding proteins can use these interactions to read a specific sequence
