370 likes | 380 Views
Explore the purpose of using alcohol in the lab, decoding DNA clumps, and learning about protein synthesis through transcription and translation processes. Get ready for quizzes with essential questions answered. Dive into the central dogma of biology and the role of different nucleic acids. Understand the importance of RNA in protein synthesis. Discover the significance of amino acids in forming proteins and the consequences of errors in transcription or translation. Uncover the secrets of DNA strands and their role in synthesizing proteins.
E N D
Warm-Up #10 2/13/13 1) What was the purpose of using alcohol in yesterday’s lab? 2) What was the purpose of using the buffer in yesterday’s lab? 3) When you looked at the DNA in the test tube, what made up the stringy-clumps? 4) Why could you not see a double helix when you look at the DNA under the microscope?
Fruit DNA Lab • We will go back to the lab today for a short amount of time • You will repeat the lab from yesterday with a different type of fruit
Warm-Up #5 2/6/12 1) Nucleotides are composed of what three things? - Phosphate, Sugar (Deoxyribose) & Nitrogen bases 2) Where is DNA located at in a Eukaryotic cell vs a Prokaryotic cell? • Eukaryote= Chromosomes in Nucleus • Prokaryote= Floating in Cytoplasm 3) List the 4 nitrogen bases of DNA. - Adenine, Guanine, Thymine, Cytosine 4) What bonds hold together a DNA molecule? - Hydrogen bonds at the bases and covalent bonds on the backbone
Warm-Up #7 2/8/12 • What is the central dogma of biology? • What is a codon? • tRNA matches a mRNA during translation this is called? • What is a promotor region? Quiz Today!
What are these structures called? Purines Pyrimidines
Using the base pairing rules, complete the following sequence of DNA. Original DNA: ATCGTTAGGCTAACCTAG Matching Strand:TAGCAATCCGATTGGATC
RNA Structure and Protein Synthesis: Transcription and Translation Chapter 12-3
Essential Question • How are proteins made during translation?
RNA • DNA cannot leave the nucleus. • Damage • Changes • It sends RNA out. • RNA is a disposable copy.
RNA Ribose Uracil Single stranded Leaves nucleus 3 types Disposable copies DNA Deoxyribose Thymine Double stranded Stays in nucleus 1 type Master copy Nucleic acids Nucleotides-nitrogen base, sugar, phosphate Adenine Guanine Cytosine
RNA • 3 types of RNA • Messenger RNA—mRNA • Carries code out of nucleus • Transfer RNA—tRNA • Transfers amino acids • Ribosomal RNA—rRNA • Ribosomes are site of protein synthesis
Central Dogma • THE BIG IDEA! • DNA RNA Protein • ReplicationTranscriptionTranslation
Protein Synthesis • Two steps: • Transcription • Translation
Transcription • Step 1: RNA polymerase (enzyme) unzips section of DNA. • Step 2: RNA nucleotides attach to DNA template. • Step 3: mRNA is assembled and detaches—leaves the nucleus to go to ribosomes in the cytoplasm.
p. 301 Adenine (DNA and RNA) Cystosine (DNA and RNA) Guanine(DNA and RNA) Thymine (DNA only) Uracil (RNA only) RNApolymerase DNA RNA
Transcription • Step 4: DNA strands zip back up. • RNA polymerase will only bond to a promoter region on the DNA—it is the starting point • RNA must be edited: Introns are out and exons are in!
Transcription • Complete the transcription of the following DNA strand: DNA: AAT CGT AGG TAC ACT CGA mRNA: UUA --- --- --- --- ---
Transcription DNA: AAT CGT AGG TAC ACT CGA mRNA: UUA GCA UCC AUG UGA GCU
Translation • Converts mRNA sequence into amino acid sequence of particular protein. • Codon: • Set of 3 mRNA bases that specifies one amino acid. • Some are start or stop codons.
Translation • tRNA also has sets of three unpaired bases which are called the anticodon. • The anticodon is complementary to one mRNA codon.
Translation • Step 1: mRNA carries message to the ribosome. • Step 2: tRNA brings the correct amino acid to the mRNA being read by the ribosome. • Step 3: rRNA holds the tRNA on the mRNA.
Translation • Step 4: Amino acids bond to form a polypeptide—a protein. The amino acid will then be released by the tRNA. • Step 5: When a stop codon is reached, the polypeptide will be released from the ribosome.
Translation Section 12-3
Practice DNA: TAC CTA AAA CCT GTA ACT transcription RNA: AUG --- --- --- --- --- translation AA: meth ___ ___ ___ ___ ___
Practice DNA: TAC CTA AAA CCT GTA ACT transcription RNA: AUG GAU UUU GGA CAU UGA translation AA: meth aspa phen glyc hist stop
Protein Synthesis • The order of the amino acids determines the properties of the proteins. • There are 20 different amino acids.
Protein synthesis • Mistakes in transcription or translation will result in a protein that is unable to do its intended job. • The whole cell will suffer and possibly the organism!
Proteins are: -Polypeptide chains of amino acids