Quiz (take out a sheet of Quiz (take out a sheet of paperpaper

1.1. T/F DNA can exit the nucleusT/F DNA can exit the nucleus

2.2. Name the bases found in RNAName the bases found in RNA

3.3. Name the enzyme used to construct Name the enzyme used to construct RNA during transcriptionRNA during transcription

4.4. BONUSBONUS► Create the matching RNA sequence for Create the matching RNA sequence for

this DNAthis DNA► ATTGGTACAATTGGTACA

Presentation outlinePresentation outline

►Review of Central Dogma of Molecular Review of Central Dogma of Molecular BiologyBiology

►Codons and anticodonsCodons and anticodons►Overview of TranslationOverview of Translation

RNA RNA protein protein

►Mistakes in DNAMistakes in DNA

Purpose of DNAPurpose of DNA

► DNA holds the genetic information.DNA holds the genetic information. A blueprint for the cellA blueprint for the cell It tells the cell what to buildIt tells the cell what to build

► The purpose of DNAThe purpose of DNA DNA codes for the proteins that make up an DNA codes for the proteins that make up an

organismorganism

► The past two days we talked about DNA The past two days we talked about DNA replication and transcription (DNA to RNA)replication and transcription (DNA to RNA)

► Today, we talk about translation (RNA to Today, we talk about translation (RNA to protein)protein)

Central Dogma of Molecular Central Dogma of Molecular BiologyBiology

1.1. DNADNA

2.2. RNARNA

3.3. ProteinProtein

RNADNA

RNApolymerase

Figure 12–14 Transcription

Section 12-3

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

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Purpose of translationPurpose of translation

►Now that the mRNA is created from Now that the mRNA is created from the DNA during transcription, the DNA during transcription, translation may begin.translation may begin.

► In translation, the appropriate In translation, the appropriate amino amino acidacid is matched with the is matched with the codonscodons (3 (3 bases) in the mRNA sequence to form bases) in the mRNA sequence to form a proteina protein Amino acids are the monomers of a Amino acids are the monomers of a

proteinprotein

Figure 12–17 The Genetic Code

Section 12-3

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The players in translationThe players in translation

► mRNAmRNA Holds the genetic code in the sequence of basesHolds the genetic code in the sequence of bases

► CodonCodon 3 consecutive bases in the mRNA sequence3 consecutive bases in the mRNA sequence

► tRNAtRNA Carries the amino acidCarries the amino acid

► AnticodonAnticodon 3 consecutive bases on the tRNA sequence3 consecutive bases on the tRNA sequence

► Ribosome (made of rRNA and proteins)Ribosome (made of rRNA and proteins) Has two spaces for mRNA and tRNA to meet and Has two spaces for mRNA and tRNA to meet and

join amino acidsjoin amino acids

Translation (slide 1 of 2)Messenger RNA Messenger RNA is transcribed in the nucleus.

Transfer RNATranslation begins at the start codon AUG. The codons match with the complimentary anticodon on the tRNA. Each tRNA has a specific amino acid attached to it. The ribosome moves over one codon

mRNA Start codon

Ribosome

Methionine

Phenylalanine tRNA Lysine

Nucleus

mRNA

Translation (slide 2 of 2)The Polypeptide “Assembly Line”As the ribosome moves along the mRNA, the amino acid chain is built. tRNAs bring in more amino acids. The ribosome (2 car garage) continues to move and read the codons on the mRNA.

mRNARibosome Translation direction

Lysine tRNA

tRNA

Ribosome

Growing polypeptide chain

mRNA Completing the PolypeptideThe process ends when it reaches a stop codon. The amino acid chain (protein) is released.

mRNA to protein (amino acid)mRNA to protein (amino acid)

Determining the Sequence Determining the Sequence of a Geneof a Gene

►DNA contains the code of instructions DNA contains the code of instructions for cells. Sometimes, an error occurs for cells. Sometimes, an error occurs when the code is copied. Such when the code is copied. Such errorserrors are called are called mutations.mutations.

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Substitution InsertionDeletion

Gene Mutations:Substitution, Insertion, and Deletion

Section 12-4

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Overview of translationOverview of translation

► mRNA is created from the DNA during mRNA is created from the DNA during transcription and exits the nucleustranscription and exits the nucleus

► The AUG codon is the starting point for The AUG codon is the starting point for translationtranslation

► Ribosome binds to the mRNA and a tRNA Ribosome binds to the mRNA and a tRNA matches its anticodon with the codonmatches its anticodon with the codon

► The tRNA has the amino acid attached to it The tRNA has the amino acid attached to it which becomes part of the protein chainwhich becomes part of the protein chain

► Translation will occur until a stop codon is Translation will occur until a stop codon is reachedreached

Review Review

1.1. DNA to DNA - Purpose of DNA DNA to DNA - Purpose of DNA replicationreplication

To make copies of the DNA for cell divisionTo make copies of the DNA for cell division

2.2. DNA to RNA – Purpose of transcriptionDNA to RNA – Purpose of transcription To make a copy of the blueprint that To make a copy of the blueprint that

codes for the amino acids (proteins)codes for the amino acids (proteins)

3.3. RNA to protein – Purpose of translationRNA to protein – Purpose of translation► Match codons from mRNA to anticodons Match codons from mRNA to anticodons

on tRNA which has the amino acid to form on tRNA which has the amino acid to form a proteina protein

Homework Homework

►Create an 8 panel cartoon describing Create an 8 panel cartoon describing the steps of TRANSLATIONthe steps of TRANSLATION

►Lab on MondayLab on Monday

Finish 2 day classwork (40 Finish 2 day classwork (40 points)points)

►Create an informational and creative Create an informational and creative poster showing the process and poster showing the process and importance of TRANSLATIONimportance of TRANSLATION

► In colorIn color►4 or less4 or less►You can use analogies to help illustrateYou can use analogies to help illustrate