Ex 4

Front 1

Adenine

Back 1

a double-ring nitrogenous base found in DNA and RNA

Front 2

AIDS

Back 2

the late stages of HIV infection. Characterized by reduced number of T Cells; usually results in death caused by opportunistic infections

Front 3

Anticodon

Back 3

on a tRNA molecule, a specific sequence of three nucleotides that is complementary to a codon triplet on mRNA

Front 4

Bacteriophage

Back 4

a virus that infects bacteria.

Front 5

Carcinogen

Back 5

a cancer-causing agent, either high-energy radiation or a chemical

Front 6

Codon

Back 6

a three-nucleotide sequence in mRNA that specifies a particular amino acid or polypeptide termination signal; the basic unit of the genetic code

Front 7

Cytosine

Back 7

a single-ring nitrogenous base found in DNA and RNA

Front 8

Deletion

Back 8

the loss of one or more nucleotides from a gene by mutation; the loss of a fragment of a chromosome

Front 9

DNA Polymerase

Back 9

an enzyme that assembles DNA nucleotides into polynucleotides using a preexisting strand of DNA as a template

Front 10

Double Helix

Back 10

the form of native DNA, referring to its two adjacent polynucleotide strands wound into a spiral shape

Front 11

Duplication

Back 11

Reptition of part of a chromosome resulting from fusion with a fragment from a homologous chromosome; can result from an error in meiosis or from mutagenesis

Front 12

Guanine

Back 12

a double-ring nitrogeneous base found in DNA and RNA

Front 13

HIV

Back 13

The retrovirus that attacks the human immune system and causes AIDS

Front 14

Inversion

Back 14

a change in a chromosome resulting from reattachment in a reverse direction of a chromosome fragment to the original chromosome. Mutagens and errors during meiosis can cause inversions

Front 15

Lysogeneic Cycle

Back 15

a bacteriophage replication cycle in which the viral genome is incorporated into the bacterial host chromosome as a prophage. New phages are not produced, and the host cell is not killed or pysed unless the viral genome leaves the host chromosome

Front 16

Lytic Cycle

Back 16

A viral replication cycle resulting in the release of new viruses by lysis of the host cell

Front 17

Messenger RNA

Back 17

the type of ribonuclieic acid that encodes genetic information from DNA and conveys it to ribosomes, where the information is translated into amino acid sequences

Front 18

Mutagen

Back 18

a chemical or physical agent that interacts with DNA and causes a mutation

Front 19

Mutation

Back 19

a change in the nucleotide sequence of DNA; the ultimate source of genetic diversity

Front 20

Nucleotide

Back 20

an organic monomoer consisting of a five-carbon sugar covalently bonded to a nitrogenous base and a phosphate group. Nucleotides are the building blocks of nucleic acids

Front 21

Oncogene

Back 21

a cancer-causing gene; usually contributes to malignancy by abnormally enhancing the amount or activity of a growth factor made by the cell

Front 22

Pathogen

Back 22

a disease-causing organism

Front 23

Peptide Bond

Back 23

the covalent linkage between two amino acid units in a polypeptide; formed by dehydration synthesis

Front 24

Purine

Back 24

one of two families of nitrogenous bases found in nucleotides. Adenine and Guanine are purines

Front 25

Pyrimidine

Back 25

one of two families of nitrogenous bases found in nucleotides. Cytosine, Thymine, and Uracil are pyrimidines

Front 26

Retrovirus

Back 26

an RNA virus that reproduces by means of a DNA molecule. It reverse-transcribes its RNA into DNA, inserts the DNA into a cellular chromosome, and then transcribes more copies of the RNA from the viral DNA. HIV and a number of cancer-causing viruses are retroviruses

Front 27

Reverse Transcriptase

Back 27

an enzyme that catalyzes the synthesis of DNA on an RNA template

Front 28

Ribosome

Back 28

a cell organelle consisting of RNA and protein organized into two subunits and functioning as the site of protein synthesis in the cytoplasm. The ribosomal subunits are constructed in the nucleolus

Front 29

Ribosomal RNA

Back 29

The type of ribonucleic acid that, together with proteins, makes up ribosomes; the most abundant type of RNA.

Front 30

RNA polymerase

Back 30

an enzyme that links together the growing chain of RNA nucleotides during transcritpion, using a DNA strand as a template

Front 31

Stop Codon

Back 31

In mRNA, one of the three triplets (UAG, UAA, UGA) that signal gene translation to stop

Front 32

Sugar-phosphate backbone

Back 32

the alternating chain of sugar and phosphate to which DNA and RNA nitrogenous bases are attached

Front 33

Thymine

Back 33

a single-ring nitrogenous base found in DNA

Front 34

Transcription

Back 34

the synthesis of RNA on a DNA template

Front 35

Transfer RNA

Back 35

a type of ribonucleic acid that functions as an interpreter in translation. Each tRNA molecule has a specific anticodon, picks up a specific amino acid, and conveys the amino acid to the appropriate codon on mRNA.

Front 36

Translation

Back 36

the synthesis of a polypeptide using the genetic information encoded in an mRNA molecule. There is a change of "language" from nucleotides to amino acids

Front 37

Translocation

Back 37

During protein synthesis, the movement of a tRNA molecule carrying a growing polypeptide chain from the A site to the P site on a ribosome.

Front 38

Uracil

Back 38

a single-ring nitrogenous base found in RNA