RNA and Protein RNA and Protein SynthesisSynthesis

Write these terms in your journalWrite these terms in your journal Ribosome Ribosome — makes proteins— makes proteins

RNA polymeraseRNA polymerase — enzyme that puts together — enzyme that puts together RNARNA

PromoterPromoter —the gene on DNA to which RNA —the gene on DNA to which RNA polymerase binds and transcription beginspolymerase binds and transcription begins

Amino acidAmino acid — monomers of proteins — monomers of proteins

PolypeptidePolypeptide — protein — protein

GenesGenes — sections of DNA that code for — sections of DNA that code for somethingsomething

What is RNA?What is RNA? RNA: RNA: RRiboibonnucleic ucleic AAcidcid

Usually single-strandedUsually single-stranded

Monomers are nucleotides (like DNA)Monomers are nucleotides (like DNA)Contains base, ribose (sugar), and Contains base, ribose (sugar), and

one phosphateone phosphate

Bases: A, Bases: A, UU, C, G ( U = Uracil ), C, G ( U = Uracil )

3 Types of RNA3 Types of RNA rRNA: ribosomal RNA—makes up ribosomerRNA: ribosomal RNA—makes up ribosome

Makes the proteins and works with tRNAMakes the proteins and works with tRNA

mRNA: messenger RNA—in the nucleus mRNA: messenger RNA—in the nucleus The The messengermessenger from DNA to rest of the cell from DNA to rest of the cell

tRNA: transfer RNA—in the cytoplasmtRNA: transfer RNA—in the cytoplasm TransfersTransfers amino acids to the ribosome to make amino acids to the ribosome to make

proteinsproteins

Protein SynthesisProtein Synthesis

Making proteinsMaking proteins

2 main steps:2 main steps: TranscriptionTranscription— written in same — written in same

“language”. “language”. DNA (nucleic acid) to DNA (nucleic acid) to mRNA (nucleic acid)mRNA (nucleic acid)

TranslationTranslation—put in a different —put in a different “language”. “language”. mRNA (nucleic acid) to mRNA (nucleic acid) to proteinprotein

TRANSCRIPTION Cont’dTRANSCRIPTION Cont’d

OCCURS IN NUCLEUS OCCURS IN NUCLEUS

(because DNA cannot leave the nucleus!)(because DNA cannot leave the nucleus!)

RNA Bonding RulesRNA Bonding Rules

(A) Adenine = (U) Uracil(A) Adenine = (U) Uracil

(G) Guanine = (C) Cytosine(G) Guanine = (C) Cytosine

TRANSCRIPTION Cont’dTRANSCRIPTION Cont’d RNA polymerase binds to the RNA polymerase binds to the

promoterpromoter, then starts bonding , then starts bonding nucleotides to make the RNA nucleotides to make the RNA strandstrand

There is a gene on DNA that There is a gene on DNA that codes for RNA polymerase to codes for RNA polymerase to stopstop

TRANSCRIPTIONTRANSCRIPTION

RNADNA

RNApolymerase

Adenine (DNA and RNA)Cystosine (DNA and RNA)Guanine(DNA and RNA)Thymine (DNA only)Uracil (RNA only)

RNA SPLICINGRNA SPLICING mRNA has to be proofread because parts of it mRNA has to be proofread because parts of it

do not code for anything. This process is called do not code for anything. This process is called RNA splicingRNA splicing..

IntronsIntrons:: parts of the mRNA strand that are useless parts of the mRNA strand that are useless and are taken and are taken OUTOUT of the mRNA strand of the mRNA strand

ExonsExons:: parts of mRNA that code for proteins and parts of mRNA that code for proteins and are left are left ININ the mRNA strandthe mRNA strand

CODONS and ANTICODONSCODONS and ANTICODONS CodonCodon:: 3 nucleotide 3 nucleotide

sequence of sequence of mRNAmRNA AnticodonAnticodon:: 3 nucleotide 3 nucleotide

sequence of sequence of tRNAtRNA that is that is complimentary to mRNAcomplimentary to mRNA

Example:Example: AUG-CGG (codons)AUG-CGG (codons) UAC-GCC (anticodons)UAC-GCC (anticodons)

START CODON: AUGSTART CODON: AUG

TRANSLATIONTRANSLATION OCCURS IN THE CYTOPLASMOCCURS IN THE CYTOPLASM ON A RIBOSOME ON A RIBOSOME

““translates” translates” nucleic acids to amino nucleic acids to amino acidsacids

mRNA is read by ribosomemRNA is read by ribosomeRibosome “translates” message Ribosome “translates” message

(mRNA) to protein(mRNA) to proteintRNA brings corresponding amino tRNA brings corresponding amino acid to ribosomeacid to ribosome

Ribosome bonds amino acids Ribosome bonds amino acids together (peptide bonds)together (peptide bonds)

TRANSLATION Cont’dTRANSLATION Cont’d When the amino acid chain lengthens, this When the amino acid chain lengthens, this

is called is called elongationelongation..

Translation stops when the ribosome Translation stops when the ribosome reads a stop codon (UAG, UAA, or UGA)reads a stop codon (UAG, UAA, or UGA)

TRANSLATIONTRANSLATION

TRANSLATIONTRANSLATION

DNADNA BOTHBOTH RNARNA

Double strandDouble strand Nucleotides: Nucleotides: (phosphate, sugar, base)(phosphate, sugar, base)

Single strandSingle strand

Base: TBase: T Bases: A, C, GBases: A, C, G Base: UBase: U

DeoxyriboseDeoxyribose SugarSugar RiboseRibose

DNA polymeraseDNA polymerase Requires Requires enzymes to make enzymes to make

moleculesmolecules

RNA polymeraseRNA polymerase

Made by Made by replicationreplication

Hydrogen and Hydrogen and covalent bondscovalent bonds

Made by Made by transcriptiontranscription

Codes for the Codes for the organismorganism

Used to make Used to make proteinsproteins

VideosVideos

Replication, Transcription, and TranslationReplication, Transcription, and Translation http://

www.youtube.com/watch?v=TSv-Rq5C3K8&feature=related

DNA TranslationDNA Translation http://www.youtube.com/watch?NR=1&feature=e

ndscreen&v=TfYf_rPWUdY

Can you identify the following in this Can you identify the following in this diagram?: DNA, mRNA, tRNA, rRNAdiagram?: DNA, mRNA, tRNA, rRNA

Can you identify the following in this Can you identify the following in this diagram?: DNA, mRNA, tRNA, rRNAdiagram?: DNA, mRNA, tRNA, rRNA

Were you right?

rRNA

Can you identify the following in this Can you identify the following in this diagram?: mRNA, tRNA, rRNA, amino diagram?: mRNA, tRNA, rRNA, amino

acids, proteinsacids, proteins

Can you identify the following in this Can you identify the following in this diagram?: mRNA, tRNA, rRNA, amino diagram?: mRNA, tRNA, rRNA, amino

acids, proteinsacids, proteins

Were you right?rRNA