Name ____________________________________ Date ____________ Period _____
PROTEIN SYNTHESIS: TRANSCRIPTION
Raven Ch. 15
Big Idea 3: Living systems store, retrieve, transmit, and respond to information essential to
life processes.
Essential Knowledge:
 Heritable information provides for continuity of life.
 Expression of genetic information involves cellular and molecular mechanisms.
 The processing of genetic information is imperfect and is a source of genetic variation.
 Cells communicate by generating, transmitting and receiving chemical signals.
 Transmission of information results in changes within and between biological systems.
Central Dogma

The “Central Dogma”

Flow of genetic information in a cell

How do we move information from DNA to proteins?

____________________ taught us about genes

Inheritance of metabolic diseases

suggested that genes coded for __________________

each disease (phenotype) is caused by _______________________ gene product

lack of an enzyme
 Tay sachs
 PKU (phenylketonuria)
 albinism
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_Metabolic Pathway_
_______
_________
_______
_______
_______
Beadle & Tatum

one gene : one enzyme hypothesis

3 Wild-type
parts
X rays or ultraviolet light
Neurospora
 _____________________ (C-N ring)

_____________________(5C)

_____________ in RNA
asexual
Minimal
 ________________ in DNA
spores
medium
 __________________________ (PO4) group
Base pairing in DNA

spores
_____________________
Select one of

double ring
N base
the
spores

_____________________ (A)

_____________________ (G)

_____________________ (T)

_____________________ (C)
Grow on
complete medium
Test on minimal
medium to_____________________
confirm
presence of mutation
single ring N base

Minimal media supplemented only with…
__________________


Growth on
complete
medium
2 hydrogen bonds
__________________
Choline
Nucleic
Arginine
3 hydrogen bonds
Niacin
Inositol acid Folic
p-Amino
acid
benzoic acid

2
Minimal
control
Thiamine
Transcription

From ___________ nucleic acid language to ____________ nucleic acid language
RNA

________________

________________

___________ instead of thymine

U:A

C:G

________________

lots of RNAs


mRNA, tRNA, rRNA, siRNA…
Making mRNA

transcribed DNA strand = ___________________

untranscribed DNA strand = ___________________


synthesis of complementary RNA strand


same sequence as RNA
___________________ bubble
enzyme

____________ polymerase
3
RNA polymerases

3 RNA polymerase enzymes


RNA polymerase 1

only transcribes ___________ genes

makes ______________________
RNA polymerase 2


RNA polymerase 3


transcribes genes into _________________
only transcribes ___________ genes
each has a specific ________________sequence it recognizes
Which gene is read?

_________________ region

binding site before beginning of gene

_______________ box binding site

binding site for _________________________________
& ___________________________________________

________________________ region

binding site far upstream of gene

turns transcription
on _________________
Transcription Factors

Initiation complex


transcription factors bind to promoter region

suite of _________________ which bind to DNA

__________________________?

turn ______________________________________
trigger the _________________________________ of RNA polymerase to DNA
4
Match RNA bases to DNA bases on one of the DNA strands
Eukaryotic genes have junk!

Eukaryotic genes are _________________________

______________ = the real gene


expressed / coding DNA
______________ = the junk

____________________ sequence
mRNA splicing

________________________________________

eukaryotic mRNA needs work after transcription

_____________________________ = _________________________________

mRNA splicing


edit out ____________________
make ___________________________ transcript
5
Splicing must be accurate

No room for mistakes!

a single base added or lost throws off the _________________________________
RNA splicing enzymes


_______________

small nuclear RNA

proteins
________________________

several snRNPs

recognize splice site sequence

cut & paste gene
Alternative splicing

Alternative ________ produced from ____________________

when is an intron not an intron…

different segments treated as exons
More post-transcriptional processing

Need to protect mRNA on its trip from nucleus to ________________

___________________ in cytoplasm attack mRNA

protect the ends of the molecule

add _____________________

add _____________________
 longer tail, mRNA lasts longer: produces more protein
6