Lecture 6

Question 1

DNA and RNA are composed of a series of smaller molecules called

Answer 1

nucleotides

Question 2

the three components of a nucleotide include the .. and … and a …

Answer 2

phosphate; sugar groups; nitrigenous base

Question 3

phosphate units link to .., forming … that make up the backbone of a polynucleotide molecule

Answer 3

sugar units; phosphodiester bonds

Question 4

the sugar group is a

Answer 4

pentose

Question 5

nucleoside: nucleotide without

Answer 5

phosphate

Question 6

nucleotide: …

Answer 6

AMP

Question 7

nucleotide di-phosphate:

Answer 7

ADP

Question 8

nucleotide tri-phosphate

Answer 8

ATP

Question 9

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 …

Answer 9

sugar-phosphate; 5’ phosphate; phosophodiester bond

Question 10

nitrogenous bases are classified into … and …

Answer 10

purines; pyrimidines

Question 11

a pyrimidine is a …-carbon ring connected by … atoms at the 1 and 3 positions

Answer 11

4; N

Question 12

the pyrimidines … and … are found in DNA, and … and …. are found in RNA

Answer 12

cytosine; thymine; cytosine; uracil

Question 13

A purine molecule is a pyrmidine ring connected to an …; the overall structure is a ….

Answer 13

imidazole ring; double ring

Question 14

…. and … are the purines in both RNA and DNA

Answer 14

adenine; guanine

Question 15

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

Answer 15

cytosine; three; thymine; two

Question 16

the directionality of the sugar-phosphate backbone results in one strand running

Answer 16

opposite to the other

Question 17

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

Answer 17

sugar; U; T; single-stranded

Question 18

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 ….

Answer 18

puripyrimidine; double helix; purines; pyrimidines

Question 19

A complete strand of human DNA has about 3 billion base pairs; uncoiled, it would be about … long

Answer 19

2 m

Question 20

histones are basic (…) proteins that bind DNA. DNA wraps around the histone, forming … that coil into a … Further condensation leads to a ….

Answer 20

positively charged; nucleosomes; chromatin fiber; chromosome

Question 21

eukaryotic chromosomes are

Answer 21

linear

Question 22

prokaryotic DNA is

Answer 22

circular

Question 23

prokaryotes have no … so the DNA is int he cytoplasm

Answer 23

nucleus

Question 24

For eukaryotes, the DNA is packaged as chromatin in the nucleus, but for prokaryotes it’s a … (…) in the cytoplasm

Answer 24

nucleoid; folded chromosome

Question 25

... hold the bacterial chromosomal loops in place

Answer 25

proteins

Question 26

topoisomerase helps DNA

Answer 26

coil

Question 27

DNA gyrase = ..., and offers many practical applications in ...

Answer 27

topoisomerase II; medicine

Question 28

cipro is an antibiotic that inhibits ... but does not affect ...

Answer 28

bacterial gyrase; eukaryotic topoisomerases

Question 29

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 ...

Answer 29

transform living cells

Question 30

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

Answer 30

die; healthy; healthy; died; living S strain

Question 31

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

Answer 31

nonliving; dead; living

Question 32

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 ...

Answer 32

digestive enzymes; did not kill the mice