MOLECULAR BIOLOGY EXAM: LATEST A+ QUESTIONS
AND ANSWERS BREAKDOWN
ATP vs. dATP
ATP has an extra OH which is why d stands for deoxyadenosine
Nucleotides in the DNA chain are covalently linked by these
phosphodiester bonds (between the 3'hydroxy group of one deoxyribose and the 5' phosphate
group of the next deoxyribose)
Draw a phosphodiester bond
Draw the cytosine
Draw thymine (DNA only)
Draw uracil (RNA only)
Draw adenine
Draw guanine
Is DNA right-handed or left-handed double helix?
right
What holds the bases together in DNA?
hydrogen bonds
A always bonds to
T
G always bonds to
C
DNA in the nucleus is bonded how?
double stranded (2) in an antiparallel orietnation (5' end to 3' end of other)
This is the term for binding two complimentary strands of DNA into a double-stranded
structure
annealing or hybridization
What is the term for separation of strands?
melting or denaturation
, What are the pyrimidine bases?
C, T, U (c.u.t pyramid cake)
What are the purine bases?
A, G
These type of interactions between bases in DNA help to stabilize it
hydrophobic
The sum total of an organism's genetic information is called its
genome
Each piece of ds-DNA is called a
chromosome
Prokaryotic (bacterial) genomes are composed of a
singular circular chromosome
How is DNA size in number of base pairs related to animal intelligence?
There is no relation. Amphibians (dumb) have highest number. Most base pairs are repetitive
DNA with no known function.
Prokaryotes use this enzyme to twist the gigantic DNA molecule into a circle called supercoils
DNA gyrase
What are the globular proteins that help are wrapped with eukaryotic DNA to help pack it
away
histones
Partially packed DNA form beads that are called
nucleosomes
Fully packed DNA is called
chromatin
Are histones mostly basic or acidic?
Basic since DNA is acidic (complimentary)
Stained chromosomes produce lighter regions called
euchromatin (higher transcription rates since less dense)
AND ANSWERS BREAKDOWN
ATP vs. dATP
ATP has an extra OH which is why d stands for deoxyadenosine
Nucleotides in the DNA chain are covalently linked by these
phosphodiester bonds (between the 3'hydroxy group of one deoxyribose and the 5' phosphate
group of the next deoxyribose)
Draw a phosphodiester bond
Draw the cytosine
Draw thymine (DNA only)
Draw uracil (RNA only)
Draw adenine
Draw guanine
Is DNA right-handed or left-handed double helix?
right
What holds the bases together in DNA?
hydrogen bonds
A always bonds to
T
G always bonds to
C
DNA in the nucleus is bonded how?
double stranded (2) in an antiparallel orietnation (5' end to 3' end of other)
This is the term for binding two complimentary strands of DNA into a double-stranded
structure
annealing or hybridization
What is the term for separation of strands?
melting or denaturation
, What are the pyrimidine bases?
C, T, U (c.u.t pyramid cake)
What are the purine bases?
A, G
These type of interactions between bases in DNA help to stabilize it
hydrophobic
The sum total of an organism's genetic information is called its
genome
Each piece of ds-DNA is called a
chromosome
Prokaryotic (bacterial) genomes are composed of a
singular circular chromosome
How is DNA size in number of base pairs related to animal intelligence?
There is no relation. Amphibians (dumb) have highest number. Most base pairs are repetitive
DNA with no known function.
Prokaryotes use this enzyme to twist the gigantic DNA molecule into a circle called supercoils
DNA gyrase
What are the globular proteins that help are wrapped with eukaryotic DNA to help pack it
away
histones
Partially packed DNA form beads that are called
nucleosomes
Fully packed DNA is called
chromatin
Are histones mostly basic or acidic?
Basic since DNA is acidic (complimentary)
Stained chromosomes produce lighter regions called
euchromatin (higher transcription rates since less dense)
