Biology Chapter 17 Part I

Front 1

5' cap

Back 1

5' end of a pre-mana molecule modified by the addition of a cap of guanine nucleotide

Front 2

A Site

Back 2

tRNA Translation, A site holds the tRNA carrying the next amino to be added to the polypeptide chain

Front 3

anticodon

Back 3

base triplet at one end of a tRNA molecule that recognized a particular complementary codon on an mRNA molecule

Front 4

base-pair substiution

Back 4

type of point mutation - replacement of one nucleotide and its partner in the complementary DNA strand by another pair of nucleotides

Front 5

codon

Back 5

three nucleotide sequence which specializes amino acids, and the stopping and starting of protein synthesis (BASIC UNIT OF GENETIC CODE)

Front 6

deletion

Back 6

loss of one or more nucleotide pairs

Front 7

e site

Back 7

tRNA during translation, place where discharged tRNA leave ribosome

Front 8

Exon

Back 8

coding region of a eukaryotic gene

Front 9

frameshift mutation

Back 9

when the number of nucleotides inserted or deleted results in improper grouping

Front 10

insertion

Back 10

mutation involving addition of one or more nucleotide pairs to a gene

Front 11

intron

Back 11

noncoding intervening sequence in a eukaryotic gene

Front 12

mRNA

Back 12

synthesized from DNA and attaches to ribosomes in the cytoplasm and specifies primary structure of protein

Front 13

missense mutation

Back 13

most common type of mutation, base substitution where new codon makes sense and still codes for an amino acid

Front 14

mutation

Back 14

rare change in the DNA of a gene, genetic diversity

Front 15

nonsense mutation

Back 15

mutation that changes amino acid codon to one of the three stop codons which shortens protein (usually not functional)

Front 16

P Site

Back 16

tRNA during translation, holds tRNA carrying growing polypeptide chain

Front 17

point mutation

Back 17

change in a gene at a single nucleotide pair

Front 18

poly-A tail

Back 18

modified end of the 3' end of an mRNA molecule consisting of the addition of some 50-250 adenine

Front 19

primary transcript

Back 19

initial RNA transcript, p-mRNA

Front 20

promoter

Back 20

specific nucleotide sequence on DNA that binds RNA polymerase and indicated where to create RNA

Front 21

reading frame

Back 21

nucleotides into codons, reading it specifies what amino acids are coded

Front 22

rRNA

Back 22

most abundant RNA, forms with proteins and forms structure of ribosomes

Front 23

Ribosome

Back 23

constructed in nucleolus, and functioning as the site of protein synthesis in cytoplasm

Front 24

RNA Polymerase

Back 24

enzyme that links together growing chain of ribonucleotides during transcription

Front 25

RNA Processing

Back 25

modification of RNA before it leaved nucleus, process unique to Eukaryote

Front 26

RNA Splicing

Back 26

removal of noncoding portions (introns) of the RNA molecule after initial synthesis

Front 27

TATA Box

Back 27

promoter DNA sequence crucial in forming the transcription inititation complex

Front 28

template strand

Back 28

DNA strand that provides the template for ordering sequence of nucleotides in an RNA transcript

Front 29

Transcription factor

Back 29

regulatory protein that binds to DNA and stimulates transcription of specific genes

Front 30

Transcription initiation complex

Back 30

completed assembly of factors and RNA polymerase bound to promotor

Front 31

Transcription unit

Back 31

region of dan molecule transcribed into RNA molecule

Front 32

tRNA

Back 32

molecule that functions as an interpreter between nucleic acid and protein language by picking up specific amino acids and attaching to appropriate codons of mRNA

Front 33

Translation

Back 33

synthesis of polypeptide using genetic info encoded in an mRNA molecule

Front 34

Triplet code

Back 34

three-nucleotide long words that specify amino acids for poly chains