Lecture 6 Flashcards
DNA and RNA are composed of a series of smaller molecules called
nucleotides
the three components of a nucleotide include the .. and … and a …
phosphate; sugar groups; nitrigenous base
phosphate units link to .., forming … that make up the backbone of a polynucleotide molecule
sugar units; phosphodiester bonds
the sugar group is a
pentose
nucleoside: nucleotide without
phosphate
nucleotide: …
AMP
nucleotide di-phosphate:
ADP
nucleotide tri-phosphate
ATP
all polynucleotides contain an alternating … backbone. This backbone is formed when the 3’ end of one nucleotide attaches to the … of an adjacent nucleotide by way of a …
sugar-phosphate; 5’ phosphate; phosophodiester bond
nitrogenous bases are classified into … and …
purines; pyrimidines
a pyrimidine is a …-carbon ring connected by … atoms at the 1 and 3 positions
4; N
the pyrimidines … and … are found in DNA, and … and …. are found in RNA
cytosine; thymine; cytosine; uracil
A purine molecule is a pyrmidine ring connected to an …; the overall structure is a ….
imidazole ring; double ring
…. and … are the purines in both RNA and DNA
adenine; guanine
chargaff’s second rule: guanine can pair only with …, using … hydrogen bonds, and adenine can pair only with .., using … hydrogen bonds. These are the base= pairing rules of the DNA double helix
cytosine; three; thymine; two
the directionality of the sugar-phosphate backbone results in one strand running
opposite to the other
DNA and RNA nucleotides differ in the type of …
In RNA, the base … is used instead of …
RNA is typically …; in some roles its folded shape is essential to its function
sugar; U; T; single-stranded
The DNA double helix features two polynucleotide strands with sugar-phosphate bacbones linked by …. pairs. The secondary structure of DNA is a …: two intertwined strands of DNA. This structure is made up of a phosphate-sugar backbone with paired nucleotide bases on the interior of the molecule. The only pairs of nucleotide bases in dNA are between … and ….
puripyrimidine; double helix; purines; pyrimidines
A complete strand of human DNA has about 3 billion base pairs; uncoiled, it would be about … long
2 m
histones are basic (…) proteins that bind DNA. DNA wraps around the histone, forming … that coil into a … Further condensation leads to a ….
positively charged; nucleosomes; chromatin fiber; chromosome
eukaryotic chromosomes are
linear
prokaryotic DNA is
circular
prokaryotes have no … so the DNA is int he cytoplasm
nucleus
For eukaryotes, the DNA is packaged as chromatin in the nucleus, but for prokaryotes it’s a … (…) in the cytoplasm
nucleoid; folded chromosome
… hold the bacterial chromosomal loops in place
proteins
topoisomerase helps DNA
coil
DNA gyrase = …, and offers many practical applications in …
topoisomerase II; medicine
cipro is an antibiotic that inhibits … but does not affect …
bacterial gyrase; eukaryotic topoisomerases
we’ve discovered that DNA is the heritable material through various experiments, starting with Griffith’s experiments on bacterial transformation
Griffith’s hypothesis: material in dead cell can …
transform living cells
Griffith injected virulent living S strain in mice, causing them to …
He then injected living nonvirulent R strain in them, leaving them …
he then injected heat-killed S strain, and the mouse was …
He injected dead S strain cells + living R strain cells, and the mouse …, and … was found int he mouse
die; healthy; healthy; died; living S strain
Griffith’s experiment showed that a bacteria’s strain and virulence must be encoded in a … chemical, as this information can be transferred from … to … bacteria
nonliving; dead; living
Avery-Macleod-McCarty transformation experiments confirmed which material was the DNA. They treated virulent, heat-killed S strain with various … They added treated S strain to living R strain and injected into mice. DNAse was the only enzyme that …
digestive enzymes; did not kill the mice
