PROTEIN SYNTHESIS TRANSLATION Explain the basic processes of

PROTEIN SYNTHESIS: TRANSLATION Explain the basic processes of transcription and translation, and how they result in the expression of genes EQ: Why are the sequence of nucleotides in DNA so important?

� Protein Synthesis: building proteins (from our genes) � Last class we used � Transcription to turn DNA RNA. � Today, we are going use � Translation to turn RNA Protein.

THE PLAYERS – WHO IS INVOLVED IN PROTEIN SYNTHESIS? • DNA: Deoxyribose Nucleic Acid, Genetic Code to Life • m. RNA: Copy of the message of the DNA, carries information in DNA out of the nucleus to make proteins. • r. RNA: Located on the ribosome. Reads the m. RNA instructions. • t. RNA: Brings amino acids to m. RNA in the ribosomes to create polypeptide chain. • Amino Acids: Monomers of proteins. • Polypeptide Chain: Polymer of proteins.

STEP 1: TRANSCRIPTION (DNA RNA) • What happens? • m. RNA is made (copied from DNA). • Where? • Occurs in the nucleus. • How? • The DNA strand is the template • RNA Bases are matched up • Why? • C G ; G C • To get the genetic information • T A out of the nucleus • A U (Instead of T) • m. RNA leaves the nucleus

Practice with Transcription: Complete on LEFT � Let’s practice transcription! I’ll give you one strand of DNA, and you complete the complementary strand of RNA. (Remember, in RNA replace A with U). � DNA strand: ATT AGG CCG GAT TAG CCT ATT � RNA strand: UAA UCC k �l

Practice with Transcription Let’s practice transcription! I’ll give you one strand of DNA, and you complete the complementary strand of RNA. (Remember, in RNA replace A with U). DNA strand: ATT AGG CCG GAT TAG CCT ATT RNA strand: UAA UCC GGC CUA AUC GGA UAA

WHAT DOES IT MEAN TO TRANSLATE SOMETHING? DNA is a Common Language: ◦ Almost all organisms share the same genetic code

TRANSLATION (TRANSLATING THE RNA PROTEINS) • What? • Turns m. RNA into Protein. • Where? • Occurs in the ribosome in the cytoplasm of the cell. • How? 1. m. RNA is read (decoded) in groups of 3 nucleotides called codons. 2. Codons are used to translate the message in m. RNA to amino acids. 3. Amino acids bond together to make protein

WHO IS INVOLVED IN TRANSLATION? • Messenger RNA (m. RNA) carries the message or instructions • ribosome (r. RNA) reads the message • transfer RNA (t. RNA) Transport/transfer the amino acid • The product amino acid (polypeptide chain) ribosome m. RNA A C C A U G U C G A U C A GU A GC A U GG t. RNA aa aa aa U A C t. RNA aa A G t. RNA aa U AG t. RNA aa

CODONS – THE CODE OF LIFE • m. RNA has the instructions, the instructions are CODONS. • A Codon is… • 3 Nucleotides (one codon) • 1 codon = 1 Amino Acid • An amino acid can have more than 1 codon code for it • Ribosomes “read” the m. RNA codons and the t. RNA retrieves the appropriate amino acid. • Some codons are special… • Start Codon: Signals the start of translation… (AUG) • Stop Codon: Signals the end of translation… (UGA, UAG)

We can use a codon chart to decode RNA. 2 nd Nucleotide 1 st Nucleotide 3 rd Nucleotide

CHECK FOR UNDERSTANDING: AUG, GGU, AND CAA, • You Try: I NEED VOLUNTEER S! Start codon • AUG • methionine Stop codons • UGA, UAG

DIFFERENT LOOK, SAME IDEA • Use this chart to Decode the following: ACC - Tht CUC - Leu GAA - Glu UGA - Stop

Protein Synthesis: All together now! TACGCACATTTACGCGG DNA codon m. RNA AUGCGUGUAAAUGCGCC ribosome AUGCGUGUAAAUGCGCC ? protein aa Met Arg Val Asn Ala Cys Ala aa aa How do we know which amino acid it codes for ?

The Genetic Code – universal! • DNA is a code for building proteins but cannot leave the nucleus so Transcribed to m. RNA • m. RNA is decode (translated) into amino acids in the ribosomes • 3 Nucleotides = 1 Codon = 1 Amino Acid • Proteins are the physical expression of our genes (DNA) • They are responsible for the visible variety of life found on Earth. • Proteins synthesis is the SAME for all living organisms.

HOW DNA MAKES PROTEINS 1. DNA 2. Transcription 3. RNA 4. Translation 5. Proteins

PRACTICE WITH PROTEIN SYNTHESIS • Let’s practice transcription! I’ll give you one strand of DNA, and you complete the complementary strand of RNA. (Remember, in RNA replace A with U). • DNA strand: TAC GCA TTA TCG ATA ATC • m. RNA strand: AUG CGU AAU AGC UAU UAG • Amnio Acid chain: Met - arg - asp - ser – tyr- stop

PROTEIN SYNTHESIS: LET’S BRING IT ALL TOGETHER! DNA Replication: (not part of P. S. ) DNA copies itself. Transcription: m. RNA is made from DNA in the nucleus. Translation: • m. RNA (from the nucleus) goes to the ribosome in the cytoplasm. • r. RNA reads the m. RNA code (from the start codon) • t. RNA transfers the correct amino acid until the stop codon is reached. The chain of amino acids builds a protein.

TRANSLATION PRACTICE �Let’s practice translation! �(Remember, 3 nucleotides=1 amino acid) • C- level 2 voice • H – ask three before me, then raise your hand • A – Complete the translation practice worksheet with your group • M- Remain seated with your pod (butt on the stool) • P- complete your own copy of the practice sheet • Success (15 min)

TRANSLATION EXIT: DNA template: TAC GGG AAG CTT GTC ATT 1. m. RNA strand: 2. amino acid chain: 2. Use the terms to describe protein synthesis: (underline each word) • Amino acid • Nucleus • Translation • Transcription • Ribosome • codon • DNA/RNA • Protein