Presentation on theme: "Bellringer- Write down 3 interesting things about DNA that you didn’t know before. On page 15. You should have learned at least 3 things."— Presentation transcript:
1 Bellringer- Write down 3 interesting things about DNA that you didn’t know before. On page 15. You should have learned at least 3 things.
2 Protein Synthesis What is protein synthesis? Is protein synthesis important?What is RNA?Where is RNA found?Is RNA similar to DNA?What is translation?
3 What is Protein Synthesis? *Protein synthesis is the buildingof proteins following theinstructions of DNA.*The instructions of DNA arewritten by the order of thebases.Example of instructions on DNA:A - G - A - T - C - T - A - G
4 Why is protein synthesis important? *Proteins make up the structure of an organism AND control all of theorganism’s chemical reactions to keep it alive.Examples of proteins:Walls of arteries, ligaments, hair, nails, muscles , bones and antibodies.
5 Protein Structure A protein is made up of a chain of AMINO ACIDS in a particular order,held together by PEPTIDE BONDS.
6 Example of Protein: *a chain of Amino Acids AlaninePhenylalanineGlutamineValineProlineLysineNAMES OF AMINO ACIDSActual Sequence and namesof AMINO ACIDSIn Blood (Hemoglobin)
7 Shapes of Proteins*the shape of a protein depends on its function & its order of amino acids.
8 Where does protein synthesis occur? DNA in the nucleus is safe !!DNA in the cytoplasm can be destroyed*The DNA never leaves the nucleus.*RNA copies the DNA in the nucleus.*RNA carries the instructions fromDNA out to the ribosome.*The protein is built on the ribosomein the cytoplasm.
9 RNA (ribonucleic acid) What is RNA?RNA (ribonucleic acid)*It is the nucleic acid responsible forthree things in protein synthesis:1 – copying instructions from DNA2 – carrying the instructions formaking proteins to the ribosome,3 – putting the protein together onthe ribosome.
10 What makes up RNA?Bases in RNASugar in RNARiboseStrands in RNA“ONE”
11 3 Types of RNA Messenger RNA (mRNA) Transfer RNA (tRNA) Ribosomal RNA (rRNA)mRNAtRNArRNA
12 Messenger RNA (mRNA) Function: Goes into the nucleus and makes a copy of DNA using RNA bases.Takes the copy to the ribosomes.Contains the “CODON” (group of 3 bases on mRNA)
13 Transfer RNA (tRNA) Function: - carries amino acids to mRNA at the ribosome to (make) the protein.- contains “ANTICODON” (3 bases that match up w/codon on mRNA)
14 Ribosomal RNA (rRNA) *ribosomal RNA major structural part of the ribosome whereprotein synthesis occurs.
15 Comparison of DNA and RNA *DNA* * RNA*Strands:Sugar: deoxyribose riboseA, G, C, T A, G, C, U Bases: *Thymine *Uracil (A – T) (A – U)
16 Steps in Protein Synthesis Part I – TranscriptionPart II – Translation:
17 Step 1: Transcription Location: in the nucleus Purpose: to copy the DNA code (order of bases) onto mRNA.Events:1.) DNA is unwound and DNA helicase unzips DNA strand.2.) RNA polymerase reads the complementary base and adds the new nucleotides along the DNA strand.3.) mRNA is made, leaves the nucleus to go to ribosome.
18 Step 1: Transcripton Location: in the nucleus Main Event: mRNA comes into thenucleus and makes acopy of the order of thebases on DNA.
19 RNA polymerase Function: Enzyme that recognizes the complementary base of RNA to DNA, and gluesthem together.Examples:Guanine with CytosineAdenine with Thymine*Uracil with Adenine
20 Step 2: Translation Location: in the cytoplasm, on the ribosome. Purpose: to convert the instructions of RNA (order of bases) into amino acids, to make proteins.
21 Step 2: Translation Events of translation: 1.) The first three bases of mRNA (codon) join the ribosome.Usually (AUG – considered the start codon).2.) tRNA brings the “amino acid” down to the ribosome. The three bases on tRNA (anticodon) match the complementary bases on mRNA.
22 Step 2: Translation … (final stage) Events of translation:3.) Each tRNA has an AMINOACID, that is determined byits anticodon.Ex: codon (AUG)Amino Acid - methionine4.) The amino acids arejoined by polypeptide bonds.5.) The resulting chain ofamino acids are called aPROTEIN.
23 Codons & Anticodons Codon – def: three nucleotides of mRNA. Start codon - AUGcodons signals the start of a polypeptide chainSTOP codons - UAA, UAG, UGA - all three ofthese codons signal the end of a polypeptide chainCodons - *C U A - *G G C - *A A C - *U U A Amino Acids Leucine - Glycine - Asparagine - LeucineANTICODON - segment of three bases on tRNAthat are complementary to the mRNA codon.