Molecular genetics Flashcards
At which carbon of ribose is the base attached in RNA/DNA?
C1
What makes up a nucleosome?
eight histones + DNA
Name the purines. Name the pyrimidines.
purines: adenine, guanine
pyrimidines: thymine, cytosine, uracil
Where are purines and pyrimidines synthesized?
liver, brain
In what part of the cell cycle does DNA replicate?
S phase
What is a nucleoside? What is a nucleotide?
nucleoside = purine/pyrimidine base + sugar
nucleotide = nucleoside + phosphate
During which phase of the cell cycle does the cell rest between divisions?
interphase
Name the 3 subdivisions of interphase.
G1, S, G2
Name the phase of the cell cycle that certain cells (e.g. muscle and nerves) can rest indefinitely in.
G0
A sample of double-stranded DNA has 10% G. What is the percentage of T?
40%
During which phase of the cell cycle do daughter cells form?
M phase
Are histones positively or negatively charged?
positively charged
Name the phase of the cell cycle in which newly synthesized DNA is checked for errors.
G2
Name the bonds that hold strands of DNA together.
Hydrogen bonds: adenine to thymine (2 bonds) and guanine to cytosine (3 bonds)
Which has two rings: the pyrimidines or the purines?
purines have two rings
pyrimidines have only one ring
Where in the cell does DNA replication occur?
nucleus
In what part of the cell does transcription occur?
nucleus
Name the phase of the cell cycle that immediately precedes DNA synthesis.
G1
Name the phase of the cell cycle in which DNA replication occurs.
S
How many carbons are in ribose?
5
At which carbons of ribose is the phosphodiester bond formed?
C3 and C5
At which end of a DNA sequence is the hydroxy group? At which end is the free phosphate group?
3’
5’
What is the functional difference between euchromatin and heterochromatin?
euchromatin is loosely packaged and readily transcribed
heterochromatin is tightly wound and cannot be transcribed
At physiological pH, is DNA/RNA positively or negatively charged?
negative
Which carbon of ribose is lacking a hydroxy group in DNA?
C2
Which has a higher melting point: DNA with a lot of A=T or DNA with a lot of G=C?
High G=C content
Name the only part of the cell cycle that is not part of interphase.
M phase
In what part of the cell does translation occur?
cytoplasm
At which carbon are the phosphates attached in ATP?
C5
