Exam I Vocabulary A

Question 1

Nucleotide

Answer 1

building blocks of DNA and RNA; consists of phosphate, nitrogenous base, and a sugar

Question 2

Nucleoside

Answer 2

consists of sugar and nitrogenous base (nucleotide without phosphate group)

Question 3

Deoxyribose Sugar

Answer 3

sugar found in DNA; pentose with 3’ and 5’ end; missing O at 2’ carbon

Question 4

Ribose Sugar

Answer 4

sugar found in RNA; pentose with 3’ and 5’ end; has OH at 2’ carbon

Question 5

Adenine

Answer 5

a purine, nitrogenous base; forms two hydrogen bonds with thymine in DNA and Uracil in RNA

Question 6

Guanine

Answer 6

a purine, nitrogenous base; forms three hydrogen bonds with cytosine in DNA and RNA

Question 7

Cytosine

Answer 7

a pyrimidine, nitrogenous base; forms three hydrogen bonds with guanine in DNA and RNA

Question 8

Thymine

Answer 8

a pyrimidine, nitrogenous base; forms two hydrogen bonds with adenine in DNA and RNA

Question 9

Uracil

Answer 9

a pyrimidine, nitrogenous base; forms two hydrogen bonds with adenine in RNA

Question 10

Purine

Answer 10

adenine or guanine; slightly larger, double ringed nitrogenous base

Question 11

Pyrimidine

Answer 11

cytosine, thymine, and uracil; slightly smaller, single ringed nitrogenous base

Question 12

Major Groove

Answer 12

wider opening to read the DNA; due to the angle of bonds more accessible for proteins

Question 13

Minor Groove

Answer 13

smaller opening to read the DNA; due to the angle of bonds, less accessible for proteins

Question 14

mRNA

Answer 14

messenger RNA; carrier information from DNA; template for protein synthesis; short life span; small percentage of cellular RNA

Question 15

tRNA

Answer 15

adaptor molecule that decodes mRNA; each tRNA is specific for a single AA; classic cloverleaf shape; accounts for 10% of cellular RNA

Question 16

rRNA

Answer 16

critical part of ribosome; contains catalytic activity as a ribozyme; accounts for 85% of cellular RNA

Question 17

Griffith’s Experiment

Answer 17

1920s; studied two types of streptococcus, rough (nonvirulent) and smooth (virulent) caused by gene for capsule coating; discovered that heat killed smooth cells combined with live rough cells killed mouse, where either one separately did not

Question 18

Avery’s Experiment

Answer 18

determined transforming factor; treated with DNases, RNases, and proteases; only the sample treated with DNase prevented transformation

Question 19

Hershey Chase Experiment

Answer 19

used radioactive labeling to determine whether proteins or DNA was the genetic material; determined that the when the DNA was radiolabelled caused the pellet to be radioactive

Question 20

Bacteriophage

Answer 20

bacterial virus; embodies central principles of molecular biology

Question 21

Phage Ghost

Answer 21

leftover vessel that infected the bacteria

Question 22

Supernatant

Answer 22

after blending and centrifugation of bacteria and phage, the liquid above the pellet that is from the phage

Question 23

Pellet

Answer 23

after blending and centrifugation of bacteria and phage, the pellet that is at the bottom formed by the bacterial cells

Question 24

Denaturation

Answer 24

the “melting” of DNA, causing it to be separated into two single strands; can be due to heat, extreme pH

Question 25

Annealing

Answer 25

the recombining of two single strands of DNA that have been denatured; lower temperature, normal pH

Question 26

Probe Hybridization

Answer 26

a fragment of DNA or RNA of variable length which can be radioactively labeled; can be used in DNA or RNA samples to detect the presence of nucleotide sequences that are complementary to the sequences