PROTEIN SYNTHESIS

REVIEW OF PROTEINS 1. Proteins are long polymers of amino acids

_____ amino acids make up proteins in living things. 3. The only difference in amino acids is the ___________ 20 “R” group

Remember proteins make up all parts of your body, including the brain, that controls learning and behavior! Proteins coded for in your DNA are hormones, enzymes, clotting factors, antibodies, contractile proteins and transport proteins. So how your body functions is also coded for by your DNA!

Transport Clotting factors (fibrin) Antibodies Enzymes Hormones

COLLAGEN ANTIBODY LUCIFERASE AMYLASE TRANSCRIPTASE DNA POLYMERASE

Twenty amino acids make up all of the proteins in the world: a) b) by being put in different orders or sequences by being put in different lengths of chains

The DNA code tells the cell three things about the protein: 1) _______ amino acids to get to make the protein, 2) ____________ to put those amino acids in to make the correct protein and 3) _____________of the amino acid chain. Which What order The length

THE GENETIC CODE AND PROTEINS REVIEW An organism’s genetic code is: in the sequence of the bases in the DNA molecule. The genetic code is for proteins—: So how your body functions is also coded for by your DNA!!!!!

Hence, our cells putting amino acids in the correct The order of the amino acids determines how a protein folds--this determines its shape and its function!!! Hence, our cells putting amino acids in the correct order for our proteins to function is crucial!!!

Hemoglobin polypeptide/protein val his leu thr pro glu glu lys ser ala val thr ala leu tyr gly lys val asn val asp glu val gly gly glu ala leu gly arg leu leu val val tyr pro try thr gln arg phe phe glu ser phe gly asp leu ser thr pro asp ala val met gly asn pro lys val lys ala his gly lys lys val leu gly ala phe ser asp gly leu ala his leu asp asp leu lys gly thr phe ala thr leu ser gln leu his cys asp lys leu his val asp pro glu asn phe arg leu leu gly asn val leu val cys val leu ala his his phe gly lys glu phe thr pro pro val gln ala ala tyr gln lys val val ala gly val ala asp ala leu ala his lys tyr his

TACCCCGGGTTTAAAATCCAGCGGTACATAGCTATC DNA’s protein code is read in groups of three base pairs called a ________. Each triplet is the code for _____ of the 20 amino acids that make up living things. A group of triplets that code for the amino acids needed to make 1 protein is called a _______. codon one gene TACCCCGGGTTTAAAATCCAGCGGTACATAGCTATC GENE = 1 PROTEIN GENE = 1 PROTEIN TRIPLET = 1 AMINO ACID

DNA which resides in the nucleus THE PROBLEM: The code for making your proteins is in: The sites to actually make proteins are on the: DNA which resides in the nucleus ribosomes that are out in the cytoplasm DNA RER RIBOSOME NUCLEUS SER DNA is too large to move through the nuclear membrane and take the code for the proteins out to the ribosomes…. so how did the cell solve this problem?

THE SOLUTION: Another smaller molecule, that can go through the nuclear membrane was created, that takes the code from: DNA, goes through the nuclear membrane and takes the code to the ribosomes. This new molecule, messenger RNA or mRNA is one of the three forms of: RNA or ribonucleic acid mRNA

RNA: THE OTHER NUCLEIC ACID. DIFFERENCES BETWEEN DNA AND RNA DNA RNA 1. DEOXYRIBOSE SUGAR 1. RIBOSE SUGAR 2. DOUBLE STRANDED 2. SINGLE STRANDED 3. THYMINE 3. URACIL 4. ONE FORM 4. THREE FORMS

DNA C●G G●C A●T T●A RNA

MESSENGER RNA--mRNA TYPES OF RNA There are three types of RNA. They all have different shapes, different functions and are located in different areas of the cell. MESSENGER RNA--mRNA Messenger RNA (mRNA) is created using a DNA molecule and thus will contain: Messenger RNA’s function is to take the protein code from DNA DNA’S protein codes or “messages” for the ribosomes. out of the nucleus to a ribosome so it can make the appropriate proteins.

Every group of three bases on mRNA is called a codon which is a code for one amino acid. codon

RIBOSOMAL RNA—rRNA large ribosomal G A C G Ribosomal RNA or rRNA is located inside a ribosome. Its function is to: large ribosomal subunit Read the code in mRNA and tell tRNA to go get amino acids that are floating in the cytoplasm. rRNA Ribosome Small ribosomal subunit

TRANSFER RNA--tRNA Transfer RNA is a cloverleaf shaped molecule that is free floating in the cytoplasm. Its function is to: The three bases on tRNA are called an ________________ Amino acid G C C pick up amino acids in the cytoplasm and bring them to mRNA to make the appropriate protein. anticodon anticodon

PROTEIN SYNTHESIS CENTRAL DOGMA (MAIN IDEA) The central dogma of protein synthesis is that DNA’s code goes from DNA to mRNA to a protein. This means that DNA will give its code to mRNA, then the mRNA, ___________________________________ are used to actually put the protein together. This process of protein synthesis includes three steps, _______________________________________________________ with the help tRNA and rRNA transcription, mRNA splicing and translation

WATCH THE ANIMATIONS…. Red part is the mRNA

Red part is the mRNA

Red part is the mRNA

WATCH THE ANIMATION…. ONE MORE TIME!

PROTEIN SYNTHESIS STEP 2: mRNA SPLICING

B. PROTEIN SYNTHESIS: mRNA SPLICING Remember, DNA has sections called INTRONS that do not code for any proteins. Since mRNA is created on DNA, it will also have introns. It would be a waste of the cell’s energy to send an mRNA molecule, full of non-coding sections, through translation which creates proteins. Before mRNA moves through the nuclear membrane: the mRNA transcript goes through a process called mRNA splicing: introns are cut out with enzymes called ribozymes. WATCH THE ANIMATIONS ON NEXT SLIDE…..

WATCH THE ANIMATIONS BELOW….

READING THE mRNA CODE

C. PROTEIN SYNTHESIS--READING mRNA’S CODE AUGCCUACUGAGUAA mRNA Each group of three bases, called a codon, codes for one of the 20 amino acids. The mRNA can be read using a codon chart. Most proteins start with the initiator, or START codon: while proteins end with one of the: AUG for the amino acid methionine. stop codons—UAA, UAG, or UGA.

This is what a codon chart looks like. CODON CHART (mRNA)

PROTEIN SYNTHESIS STEP 3: TRANSLATION

WATCH THE ANIMATION BELOW….

CYTOPLASM TRANSLATION A U G C A U G C U A U C A C A C G G A U A A I I I I I I I I I I I I I I I I I I E P CGUA G a u A G U C C C A U U G u g C c u uac AMINO ACID tRNA MET GLY SER LEU HIS PRO ANTICODON PEPTIDASE E, P AND A SITES LRS NUCLEUS STOP CODON rRNA SRS CODON mRNA

uac A G U C C C A U U C c u G a u G u g U A C G A U A G U G U G C C U TRANSLATION MET uac HIS LEU GLY A G U C C C A U U C c u SER G a u G u g PRO PEPTIDASE PEPTIDE BOND PROTEIN A U G C U A C MET G A U ● LEU ● SER A G U G U G ● HIS ● GLY C C U A U U RELEASE FACTOR E P A A U G C U A U C A C A C G G A U A A I I I I I I I I I I I I I I I I I I CGUA STOP CODON

uac A G U A U U C c u G a u G u g C C C U A C G A U A G U G U G C C U MET TRANSLATION ELONGATION uac HIS LEU GLY A G U A U U C c u SER G a u G u g C C C PRO PEPTIDASE PEPTIDE BOND PROTEIN A U G C U A C MET G A U ● LEU ● SER A G U G U G ● HIS ● GLY C C U A U U RELEASE FACTOR E P A CGUA A U G C U A U C A C A C G G A U A A I I I I I I I I I I I I I I I I I I STOP CODON