Ap Bio (Chapter 17 - Rna Transcription/translation)

Front 1

gene expression

Back 1

DNA directs synthesis of proteins indrectly.

Front 2

1909 - Archibald Garrod

Back 2

Proposed that genes dictated phenotypic expressions through enzymes that catalyze specific chemical reactions.
Disease = inability to make enzyme.

Front 3

George Beadle and Borris Ephrussi (1930's)

Back 3

tested in Drosphilia and mold to find that, when DNA was damaged, a certain protein could not be produced depending on what stage was halted by X rays.

Front 4

One gene-one polypeptide

Back 4

the law made by Beadle and Ephrussi that states that each gene codes for a polypeptide (because genes make both enzymes and proteins, and sometimes more than one polypeptide makes a protein.

Front 5

Transcription

Back 5

synthesis of mRNA that carries genetic message to protein-synthesizing machine.

Front 6

Translation

Back 6

the process of synthesizing polypeptide chains under the direction of mRNA and ribosomes.

Front 7

Triplet Code/codon

Back 7

3 nucleotide bases code for 1 amino acid on the mRNA.

Front 8

template strand

Back 8

one of the 2 DNA strands that is used for transcription and is read from 3' to 5'.

Front 9

Marshall Nirenberg (1961)

Back 9

first deciphered a codon.

Front 10

AUG

Back 10

start codon, coding for the amino acid Methanine.

Front 11

RNA polymerase II

Back 11

takes apart DNA strands and hooks RNA on, assembling RNA in 5' to 3' direction. no primer needed.

Front 12

Promoter

Back 12

DNA sequence where RNA polymerase attaches and initiates.

Front 13

TATA box

Back 13

where the transcription factors bind so the RNA polymerase can bind to them.

Front 14

Transcription Factors

Back 14

proteins that help RNA polymerase bind to the promoter.

Front 15

Terminator

Back 15

sequence signaling the end of transcription.

Front 16

Transcription Unit

Back 16

The complex in which the RNA is transcribed (stretch of DNA)

Front 17

Transcription-Initation complex

Back 17

RNA polymerase with Transcription factors and promoter.

Front 18

Elongation

Back 18

when RNA nucleotides are added to the 3' end, exposing only 10-20 DNA bases at a time.

Front 19

Polyadenylation Signal Sequence
(AAUAAA)

Back 19

the sequence that signals the pre-mRNA to leave the complex and continue to processing. the RNA polymerase doesn't detach until further downstream.

Front 20

5' cap

Back 20

at the 5' end of mRNA to protect it, there is a G3P or Guanine 3 Phosphate attached.

Front 21

Poly A Tail

Back 21

50-250 Adenines that are added at the 3' end of mRNA to protect it.

Front 22

UTR

Back 22

untranslated regions that help with binding but not with translation in RNA.

Front 23

RNA splicing

Back 23

when the Introns (noncoding sequences) are taken out and the Exons (coding sequences) spliced together.

Front 24

Small Nuclear Ribonuclearproteins
(snRNP's - "snurps")

Back 24

RNA and Proteins that help in splicing RNA.

Front 25

Spliceosome

Back 25

joins with "Snurps" and splices RNA.

Front 26

tRNA

Back 26

RNA on an amino acid with anticodon

Front 27

anticodon

Back 27

matches to codon and is found on the tRNA

Front 28

amino acid attachment site

Back 28

3' end of mRNA

Front 29

aminoacyl tRNA synthetase

Back 29

enzyme that creates aminoacyl tRNA (active tRNA (tRNA with amino acid))

Front 30

wobble

Back 30

relaxed base pairing rule, mostly relevant to the third base.

Front 31

A site (aminoacyl tRNA binding site)

Back 31

first binding place on ribosome where the tRNA can bind.

Front 32

P site (peptidyl tRNA binding site)

Back 32

second ribosome binding site where the tRNA deposits its amino acid.

Front 33

E (Exit) site

Back 33

site on the ribosome where the tRNA without the amino acid is ejected.

Front 34

Ribosomal RNA (rRNA)

Back 34

RNA that makes up ribosomes; made in nucleolus.

Front 35

exit tunnel

Back 35

where the popypeptides exit the ribosome.

Front 36

initiator tRNA

Back 36

contains the start codon AUG with the amino acid Methionine

Front 37

initiation factors

Back 37

bring together components for translation.

Front 38

reading frame

Back 38

established by first codon and keeps reading 3 codons at a time.

Front 39

GTP

Back 39

energy to form complex for translation

Front 40

Elongation factors

Back 40

proteins that help with the process of translation. hydrolyze G3P

Front 41

codon recognition

Back 41

anticodon pairs with RNA at A site and use 2GTP for energy.

Front 42

peptide bond formation

Back 42

when the new amino acid covalently bonds with the amino acid chain. GTP used.

Front 43

translocation

Back 43

when the used up or "empty" tRNA in the P site is moved to the E site and ejected and the tRNA in the A site is moved to the P site.

Front 44

stop codon

Back 44

UAG, UAA, or UGA
enters A site to end translation

Front 45

polyribosomes

Back 45

strings of ribosomes working on the same mRNA

Front 46

chaperomin

Back 46

helps the protein fold correctly after translation

Front 47

polysomes

Back 47

polyribosomes

Front 48

signal recognition particle (SPR)

Back 48

binds fto signal peptide and stops synthesis for a moment in the cytosol, allowing it to bind to receptor protein in ER membrane.

Front 49

translocation complex

Back 49

the protein, ribosome, ER complex where the protein is synthesized into the ER.

Front 50

mRNA (messanger RNA)

Back 50

carries information specifying amino acid sequences for proteins from DNA.

Front 51

tRNA (transfer RNA)

Back 51

adaptor molecule in protein synthesis that translates mRNA into amino acids.

Front 52

Primary transcript (pre-mRNA)

Back 52

precursor to mRNA, rRNA and tRNA. intron RNA acts as ribosome to catalyze its own splicing.

Front 53

SPR RNA

Back 53

signal recognition particle RNA. protein RNA complex recognizing signal peptides of polypeptides targetted to ER>

Front 54

small nuclear RNA (snRNA)

Back 54

makes splicosomes with proteins that splice introns in pre-mRNA.

Front 55

small nucleolar RNA (snoRNA)

Back 55

processing pre-rRNA in the nucleolus.

Front 56

small interfering RNA (siRNA) or micro RNA (miRNA)

Back 56

regulation of gene expression.

Front 57

mutations

Back 57

changes in genetic material of a cell.

Front 58

point mutations

Back 58

chemical changes in one base pair of a DNA sequence.

Front 59

substitution mutations

Back 59

when a single base is substituted for another base.

Front 60

silent mutations

Back 60

mutations with no effect

Front 61

missense mutations

Back 61

altered codon codes for amino acid that makes sense but not right sense or amino acid.

Front 62

nonesense mutations

Back 62

mutated codon codes for stop mutation and translation is terminated prematurely.

Front 63

insertion mutation

Back 63

addition of nucleotide pair or codon.

Front 64

deletion mutation

Back 64

deletion of a nucleotide pair or codon.

Front 65

frame shift mutation

Back 65

when the reading frame is shifted and all codons downstream are misread.

Front 66

mutagens

Back 66

causes DNA mutations

Front 67

spontanious mutations

Back 67

errors in DNA

Front 68

gene

Back 68

region of DNA whose final product is either a polypeptide or an RNA molecule.