Biology Key Terms Chap. 9 & 10

Front 1

substance prepared from killed or weakened pathogens and introduced into a body to produce immunity

Back 1

vaccine

Front 2

referring to the deadlines of a disease-causing agent

Back 2

virulent

Front 3

the transfer of genetic material from one organism to another; first obvserved by Griffith

Back 3

transformation

Front 4

virus that infects bacteria

Back 4

bacteriophage

Front 5

spiral-staircase structure characteristic of the DNA molecule

Back 5

Double helix

Front 6

subunit of nucleic acids consisting of a nitrogenous base, a sugar, and a phosphate group

Back 6

nucleotide

Front 7

five-carbon sugar that is a component of DNA nucleotides

Back 7

deoxyribose

Front 8

the rule stating that in DNA adenine on one strand always pairs with a thymine on the opposite strand and guanine on one strand always pairs with cytosine on the opposite strand

Back 8

base-pairing rules

Front 9

characterisitc of nucleic acids in which th esequence of bases on one strand determines the sequence of bases on the other

Back 9

Complementary

Front 10

the process of making a copy of DNA

Back 10

DNA replication

Front 11

enzyme that breaks the hydrogen bonds between bases during DNA replication

Back 11

DNA helicase

Front 12

a Y-shaped point that results when a double helix of DNA separates so that it can be copied

Back 12

Replication fork

Front 13

enzyme that catlyzes the replication of DNA by adding complementary nucleotides

Back 13

DNA polymerase

Front 14

a type of nucleic acid involved in protein synthesis

Back 14

RNA

Front 15

nitrogen-containing base of RNA, complementary to adenine when RNA base pairs with DNA

Back 15

Uracil

Front 16

stage of protein synthesis in which the information in DNA for making a protein is transferred to an RNA molecule

Back 16

transcription

Front 17

stage of gene expression in which the information in mRNA is used to make a protein

Back 17

Translation

Front 18

two-stage processing of information encoded in DNA to produce proteins

Back 18

gene expression

Front 19

enzyme that adds and links complementary RNA nucleotides during transcription

Back 19

RNA polymerase

Front 20

RNA copy of a gene used as a blueprint for the making of a protein during translation

Back 20

Messenger RNA

Front 21

a three nucleotide sequence in DNA or mRNA that encodes an amion acid or signifies a stop signal

Back 21

codon

Front 22

sequence of nucleotides that specifies the amino acid sequence of a protein

Back 22

genetic code

Front 23

RNA molecule that temporarily carries a specific amino acid to a ribosome during translation

Back 23

Transfer RNA

Front 24

a three-nucleotide sequence on tRNA that recognizes a complementary codon on mRNA

Back 24

anticodon

Front 25

type of RNA molecule that plays a stuctural role in ribosomes

Back 25

Ribosomal RNA

Front 26

region of DNA that controls RNA polymerase's access to a set of genes with related functions

Back 26

operator

Front 27

segment of DNA that controls gene regulation in a set of genes with related functions in prokaryotes

Back 27

operon

Front 28

gene system with a promoter, an operator gene, and three structural genes that control lactose metabolism

Back 28

lac operon

Front 29

protein that binds to the operator in an operon to switch off transcription

Back 29

repressor

Front 30

segment of mRNA transcribed form eukaryotic DNA but removed before translation of mRNA into a protein

Back 30

intron

Front 31

sequence of nucleotides on a gene that gets transcribed and translated

Back 31

exon

Front 32

mutation in which on or just a few nucleotides in a gene are changed

Back 32

point mutation