understanding rna
DESCRIPTION
Understanding RNA. R ibo n ucleic A cid. A. Sugar ( ribose ). B. Phosphate Group. 1 . Made of Nucleotides:. C. Nitrogen Bases. B. A. C. A. Cytosine Guanine (C G). B. Adenine Uracil (A U). - PowerPoint PPT PresentationTRANSCRIPT
Understanding RNA
Ribonucleic
Acid
1. Made of Nucleotides:
A
B
C
B. Phosphate Group
A. Sugar (ribose)
C. Nitrogen Bases
2. Rules for Base Pairing:
A. Cytosine Guanine
(C G)
Notice that RNA has Uracil (not thymine)
B. Adenine Uracil
(A U)
* helps to make protein
4. Types of RNA
A. Messenger (mRNA)
B. Transfer (tRNA)
C. Ribosomal (rRNA)
3. What is the functionof RNA?
Sugar
(ribose) Phosphate Group
Nitrogen Base
Comparing DNA & RNA
DNA RNA
Sugar is deoxyribose
Sugar is
ribose
Adenine base is present
Cytosine base is present
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DNA RNA
Guanine base is present
Thymine base is present
Uracil base is present
Shape is double helix
Comparing DNA & RNA
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Comparing DNA & RNA
DNA RNA
Shape is single stranded
Located in nucleus only
Composed of nucleotides
Stores genetic information
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Comparing DNA & RNA
DNA RNA
Helps to make proteins √
Protein Synthesis:
How Proteins are Made
Making Proteins is a Two Step
Process:
Transcription – making a mRNA copy of DNA; occurs in the nucleus
Step 1:
Why Transcription?
DNA contains volumes of information about making protein.
Unfortunately, DNA is too huge to leave the nucleus but the protein is made in the ribosomes.
Don’t Write This Slide, Just Read!!!
Summary of Transcription
A. The DNA molecule unzipsat the nitrogen bases
B. mRNA nucleotides pair upwith DNA nucleotides(one side)
Summary of Transcription
C. DNA “rezips” and mRNA
leaves the nucleus
Click Here for Transcription Animation
Translation – amino acids are being assembled into proteins; occurs in the ribosomes
Step 2:
Summary of Translation
A. mRNA enters the ribosome
B. 3 mRNA nucleotides(codons) pair up with 3 tRNA
nucleotides (anticodons)
C. amino acids are added until
the “stop” message is reached
Click Here for Translation Animation
* Codon – three mRNA bases
* Anticodon – three tRNA bases
* 1 codon makes 1 amino acid; 3 nitrogen bases makes
1 amino acid
Example:
DNA: TAC – AGG – GGT - ACG – CCG – AAT – GGG – ATT –
tRNA:
Amino
Acid:
DNA:
mRNA: – UCC – CCA – UGC – GGC – UUA – CCC – UAA - AUG
Example:
DNA: GCA – AAT- TTA
tRNA:
Amino
Acid:
mRNA: CGU – UUA - AAU
Example:
DNA: TAC – AGG – GGT - ACG – CCG – AAT – GGG – ATT –
mRNA: AUG – UCC – CCA – UGC – GGC – UUA – CCC – UAA -
Amino
Acid:
tRNA: UAC – AGG – GGU– ACG– CCG – AAU – GGG– AUU -
Example:
DNA: GCA – AAT- TTA
mRNA: CGU – UUA - AAU
GCA
Amino
Acid:
tRNA: – AAU - UUA
Use mRNA to find the Amino Acid on the Chart
Write this on the bottom of your “Chart of Amino Acids”:
U C A G
UPhenylalaninePhenylalanineLeucineLeucine
SerineSerineSerineSerine
TyrosineTyrosineStopStop
CysteineCysteineStopTryptophan
UCAG
C LeucineLeucineLeucineLeucine
ProlineProlineProlineProline
HistidineHistidineGlutamineGlutamine
ArginineArginineArginineArginine
UCAG
A IsoleucineIsoleucineIsoleucineMethionine
ThreonineThreonineThreonineThreonine
AsparagineAsparagineLysineLysine
SerineSerineArginineArginine
UCAG
GValineValineValineValine
AlanineAlanineAlanineAlanine
Aspartic AcidAspartic AcidGlutamic AcidGlutamic Acid
GlycineGlycineGlycineGlycine
UCAG
FirstmRNA Base
Second mRNA Base
ThirdmRNABase
Example:
DNA: TAC – AGG – GGT - ACG – CCG – AAT – GGG – ATT –
mRNA: AUG – UCC – CCA – UGC – GGC – UUA – CCC – UAA -
tRNA: UAC – AGG – GGU – ACG – CCG – AAU – GGG – AUU -
Amino
Acid:Met – Ser – Pro – Cys – Gly – Leu – Pro - STOP
Codon
Anticodon