Amino Acids Frederick Sanger 1952: - proteins consist of
__________ of molecules called amino acids - specific sequence of
________ _______determines chemical properties of each protein -
proteins produced by cell determine __________, ________ &
______________ of cell Proteins responsible for ____________ traits
Sequence of _________ _________ in DNA makes up genetic code of
organism Genetic code determines how amino acids strung together
(how proteins are made)
Slide 3
Genetic Code In a gene: each set of 3 bases is a _________
Genetic code always ____________ in terms of _________ codon rather
than original DNA sequence Each mRNA codon ________ for a specific
________ ______ Only 20 amino acids found in proteins, depend on
combination of bases in codon _________ and __________ codons
initiate or terminate protein synthesis
Slide 4
Ex) A U G C U U A A A G C C U G A
Slide 5
Gene Expression Way information in a gene is _________ into a
specific trait through production of a _____________ (protein) -
products of all genes = polypeptides ___________ is utilized to
convert ______ into ________ - __________ RNA (mRNA) - __________
RNA (tRNA) - __________ RNA (rRNA) 2 stages of gene expression:
__________ and ___________ Transcription: genetic information
converted from ______ __________ into mRNA, __________ information
from _______ to __________ Translation: genetic _________ from mRNA
used to _________ polypeptide chains of specific amino acids
Slide 6
Gene Expression Central Dogma: 2 step process of ________
genetic information from ________ to ________, then from ________
to _________
Slide 7
Transcription Overview DNA sequence _________ (transcribed)
into the ________ of a _______ stranded ________ molecule THREE
PROCESSES: 1. Initiation: RNA ________ binds to DNA at _______ site
near ________ of gene 2. Elongation: RNA polymerase uses DNA as
_______ to build ____________ molecule 3. Termination: RNA
polymerase ______ the end of ______ and ________ mRNA then
_________ from template strand _________ through _________ pores,
into _________ of cell
Slide 8
Transcription Initiation Only one strand of the double-stranded
DNA is ____________ for each gene - template strand: one that is
transcribed - _______ strand can serve as the _________ strand for
different genes ________ _____________ binds to segment of DNA -
________ double helix - binds in front of _______ to be
transcribed
Slide 9
Transcription - Elongation DNA strand to be transcribed =
template RNA _________ moves along template strand of DNA and
begins _________ __________ in 5 to 3 direction mRNA strand
_____________ to DNA template strand EXCEPT _________ is _________
with ____________
Slide 10
Transcription - Termination RNA polymerase reaches _____ of
________ Termination sequence: RNA polymerase ___________ it as end
Transcription stops, mRNA ______________ from DNA template strand
RNA polymerase free to bind to another promoter site - transcribe
another gene mRNA free and _________ out of nucleus into
cytoplasm
Slide 11
Review Transcription
Slide 12
Translation Overview mRNA now in the __________ needs to be
_________ - puts _______ __________ together according to genetic
information and creates ________ ____________: site of translation
- composed of 2 subunits: ________ together around mRNA, ________
______ mRNA THREE PROCESSES: 1. Initiation 2. Elongation 3.
Termination
Slide 13
Translation - Initiation Occurs when _____________ recognizes
specific sequence on mRNA ______ to it Ribosome _______ along mRNA
in 5 to 3 direction - ____ amino acids to polypeptide chain once it
reads a ________ Must start reading in correct ________ on mRNA -
_________ codon (AUG) - ensures ribosome ______________ code using
reading frame of mRNA molecule - results in _________ sequence of
amino acids __________ RNA (tRNA) carries amino acids back to
ribosome structure of tRNA contains an _________________ -
___________ to _________ of mRNA - tells tRNA which amino acid to
bind to - amino acid _________ to opposite end - tRNA ___________
amino acid to ribosome
Slide 14
tRNA Structure
Slide 15
Translation - Elongation Start codon recognized by ribosome -
codes for _____________ 2 sites for tRNA to attach - A (aminoacyl)
- P (peptidyl) tRNA with anticodon complementary to start codon
_______ P site Next tRNA carrying required amino acid enters the
_______ site - peptide bond formed between both amino acids
Ribosome _____________ over one codon so that _________ tRNA is now
in P site _________ first tRNA from P site and allowed THIRD tRNA
to enter ___________ A site - like a tickertape! Released tRNAs
__________ back into cytoplasm
Slide 16
Slide 17
Translation - Termination Ribosome reaches one of THREE ______
CODONS - UGA, UAG, UAA Do not _______ for an amino acid, no
____________ tRNAs Protein release _______ recognizes that ribosome
has stalled and helps release _____________ chain from ribosome
TERMINATION. Translation Transcribe & Translate!