800 likes | 894 Views
Today in Biology. Homework : Lab report Due Nov 19 Tomorrow. Week #6 Quarter 2 ( 11/18) . Biology Learning Goal: Overview of chapter 6 – Genes, DNA, Chromosomes and chromatids. Warm Up Question : Guanine pairs with _______________ Thymine pairs with _______________.
E N D
Today in Biology Homework: Lab report Due Nov 19 Tomorrow Week #6 Quarter 2 (11/18) Biology Learning Goal: Overview of chapter 6 – Genes, DNA, Chromosomes and chromatids Warm Up Question: Guanine pairs with _______________ Thymine pairs with _______________ Fact of the Day It takes about 12 hours for food to entirely digest Cytosine Adenine To Do Today: 5 min to finish pg.16&17 Concept map Pg. 18 reading DNA replication
Today in Biology Homework: Quiz Friday Week #6 Quarter 2 (11/19) Biology Learning Goal: Overview of chapter 6 – Genes, DNA, Chromosomes and chromatids Warm Up Question: What is the complementary strand of the following DNA strand: TATTTCCGGACGCGGAAT ? Fact of the Day The length of your thumb is about the same as that of your nose. ATAAAGGCCTGCGCCTTA To Do Today: Lab Report due Complete and check concept map Read pgs. 198-200 Complete handouts pg.19&20
WATSON & CRICK FRANKLIN & WILKINS AMOUNT OF BASE PAIRS DOUBLE HELIX REPLICATION PURINE PYRAMIDINE DNA PLOYMERASE NITROGEN BASE PHOSPHATE 5 CARBON SUGAR 5 handout
Read pgs. 198-200 Complete handouts pg.19&20
Today in Biology Homework: Quiz Friday Week #6 Quarter 2 (11/20&21) Biology Learning Goal: Overview of chapter 6 – Genes, DNA, Chromosomes and chromatids Warm Up Question 1. Who first photographed DNA? 2. What is the shaped of DNA? Fact of the Day With more than 80,000 arms, the Basket Starfish has the greatest number of arms. Rosalind Franklin Double Helix To Do Today: *complete handouts from Tuesday Read/skim pages 208-219 Notes on protein synthesis *handout *Transcription and Translation coloring handout
How DNA decides our traits… • A gene, is a section of the DNA strand that gives the code for one protein. • The proteins coded for in each gene dictate how an organism will develop: regulate cell processes, construct muscle & bone, fight diseases…
Protein Synthesis • The production (synthesis) of polypeptide chains (proteins) • Two phases: Transcription & Translation • mRNA must be processed before it leaves the nucleus of eukaryotic cells 2
DNA RNA Protein DNA Transcription mRNA Ribosome Translation Protein Prokaryotic Cell 3
DNA RNA Protein Nuclear membrane DNA Transcription Pre-mRNA RNA Processing mRNA Ribosome Translation Protein Eukaryotic Cell 4
First We Need RNA • Ribose Nucleic Acid • Similar to DNA but: • smaller and single stranded • The sugar is ribose instead of deoxyribose • Contains all the same bases except thymine is replaced with uracil (so RNA has G, C, A, U)
There are 3 kinds of RNA used in protein synthesis: • mRNA (messenger RNA) • tRNA (transfer RNA) • rRNA (ribosomal RNA)
Now that we know about DNA and RNA we can learn Protein Synthesis. • Protein Synthesis is the process of making a protein from DNA. • It has 2 parts: Transcription and Translation.
Transcription- Write (scribe) • The synthesis of mRNA from a DNA blueprint. • This occurs in the nucleus, then the mRNA travels out of the nucleus.
Translation - Read • The information in the mRNA is translated by a ribosome (made of rRNA), who “reads” it. • Transfer RNA (tRNA) enters the ribosome to drop off an amino acid. • A chain of amino acids then exits the ribosome and folds into a protein.
How does the tRNA match up to the mRNA:Codon & Anticodon • CODON: three consecutive nucleotides in mRNA. Each codon codes for a single amino acid. • ANTICODON: three consecutive nucleotides in tRNA that pair to a codon.
copy How DNA determines everything in our body. DNA Replication DNA Transcription Protein Synthesis RNA Translation Protein
Transcription Translation 28
Start & Stop Codons • START CODON= tells the ribosome to start translating the mRNA. • STOP CODON= tells the ribosome to stop translating the mRNA.
Messenger RNA (mRNA) • Carries the information for a specific protein • Made up of 500 to 1000 nucleotides long • Sequence of 3 bases called codon • AUG – methionine or startcodon • UAA, UAG, or UGA – stopcodons 40
start codon Primary structure of a protein stop codon Messenger RNA (mRNA) protein methionine glycine serine isoleucine glycine alanine codon 1 codon 2 codon 3 codon 4 codon 5 codon 6 codon 7 A U aa2 G G G aa3 C U C C aa4 A U C G aa5 G C G aa6 C A U A A aa1 mRNA peptide bonds 41
Transfer RNA (tRNA) • Made up of 75 to 80 nucleotides long • Picks up the appropriate amino acid floating in the cytoplasm • Transports amino acids to the mRNA • Have anticodons that are complementary to mRNA codons • Recognizes the appropriate codons on the mRNA and bonds to them with H-bonds 42
amino acid attachment site Transfer RNA (tRNA) methionine amino acid U A C anticodon 43
Ribosomal RNA (rRNA) • Made up of rRNA is 100 to 3000 nucleotides long • Made inside the nucleus of a cell • Associates with proteins to form ribosomes 44
Ribosomes • Made of a large and small subunit • Composed of rRNA (40%) and proteins (60%) • Have two sites for tRNA attachment --- P and A 45
mRNA Ribosomes A U G C U A C U U C G Large subunit P Site A Site Small subunit 46
Translation Synthesis of proteins in the cytoplasm Involves the following: 1.mRNA (codons) 2.tRNA (anticodons) 3.ribosomes 4.amino acids 47
Translation Three steps: 1.initiation: start codon (AUG) 2.elongation: amino acids linked 3.termination: stop codon (UAG, UAA, or UGA). Let’s Make a Protein ! 48
mRNA mRNA Codons Join the Ribosome A U G C U A C U U C G Large subunit P Site A Site Small subunit 49
Initiation aa1 aa2 1-tRNA 2-tRNA U A C G A U anticodon A U G C U A C U U C G A hydrogen bonds codon mRNA 50
aa3 3-tRNA G A A Elongation peptide bond aa1 aa2 1-tRNA 2-tRNA anticodon U A C G A U A U G C U A C U U C G A hydrogen bonds codon mRNA 51
aa3 3-tRNA G A A aa1 peptide bond aa2 1-tRNA U A C (leaves) 2-tRNA G A U A U G C U A C U U C G A mRNA 52 Ribosomes move over one codon
aa4 4-tRNA G C U peptide bonds aa1 aa2 aa3 2-tRNA 3-tRNA G A U G A A A U G C U A C U U C G A A C U mRNA 53
aa4 4-tRNA G C U peptide bonds aa1 aa2 aa3 2-tRNA G A U (leaves) 3-tRNA G A A A U G C U A C U U C G A A C U mRNA 54 Ribosomes move over one codon
aa5 5-tRNA U G A peptide bonds aa1 aa2 aa4 aa3 3-tRNA 4-tRNA G A A G C U G C U A C U U C G A A C U mRNA 55
aa5 5-tRNA U G A peptide bonds aa1 aa2 aa3 aa4 3-tRNA G A A 4-tRNA G C U G C U A C U U C G A A C U mRNA 56 Ribosomes move over one codon
aa5 aa4 Termination aa199 aa200 aa3 primary structure of a protein aa2 aa1 terminator or stop codon 200-tRNA A C U C A U G U U U A G mRNA 57
End Product –The Protein! aa5 aa4 aa3 aa2 aa199 aa1 aa200 • The end products of protein synthesis is a primary structure of a protein • A sequence of amino acid bonded together by peptide bonds 58
SUMMARY OF PROTEIN SYNTHESIS • A section of DNA opens • Free floating nucleotides connect up to one side of the DNA making mRNA (Transcription). • The mRNA travels out of the nucleus & into the cytoplasm. • A ribosome “reads” the mRNA and pairs the codon of mRNA with the anticodonof tRNA, which drops off amino acids to make a chain. (Translation) • The chain of amino acids exits the ribosome and folds up = protein!
Today in Biology Homework: Quiz Monday Week #6 Quarter 2 (11/22) Biology Learning Goal: Overview of chapter 6 – Genes, DNA, Chromosomes and chromatids Warm Up Question–warmup reflection Fact of the Day There are more insects in a single square mile of fertile soil than there are people on the entire earth. Why do you think protein synthesis research has been focused to prokaryotes rather than eukaryotes? To Do Today: Review notes Turn in Protein Synthesis Act. Begin coloring review
Today in Biology Homework: None Week #7 Nov 25-27 Quarter2 (11/25) Biology Learning Goal: Overview of chapter 6 – Genes, DNA, Chromosomes and chromatids Warm Up Question– What enzyme unzips the DNA double helix? The point where the DNA is apart is called the Fact of the Day Dolphins only "sleep" half awake - keeping one eye open while consciously breathing and floating on surface. Helicase Replication Fork • To Do Today: • Review Protein Synthesis Notes • Finish coloring Transcription and Translation • Quiz
Proteins • Proteins are made of 20 different amino acids. • The sequence of amino acids varies between each protein, and tells it how to fold, giving the protein its shape.
What if something goes wrong in coding? • MUTATIONS (an error in DNA) • CAN OCCUR WITH JUST A SINGLE BASE PAIR CHANGE. • BASE SUBSTITUTION- when a TA pair is replaced by a GC pair in DNA. -If it occurs in a specific location, for instance, in the CFTR gene, it will cause cystic fibrosis. • BASE DELETIONS & INSERTIONS- when base pairs are added or removed from the gene.
MUTATIONS OCCUR DURING DNA REPLICATION. • MUTATIONS (an error in DNA) • USUALLY THE ERROR IS EDITED OUT BY THE DNA POLYMERASE (proof-reader), AND FIXED BY THE REPAIR ENZYMES. • MUTAGENS- An environmental factor that damages DNA and are most likely to blame for mutations. EX: ultra violet rays & chemicals in cigarette smokenuclear radiation
Mutation is the alteration of DNA sequence, whether it be in a small way by the alteration of a single base pair, or whether it be a gross event such as the gain or loss of an entire chromosome. It may be caused through the action of damaging chemicals, or radiation, or through the errors inherent in the DNA replication and repair reactions. One consequence may be genetic disease. However, although in the short term mutation may seem to be a BAD THING, in the long term it is essential to our existence. Without mutation there could be no change and without change life cannot evolve. If it had not been for mutation the world would still be covered in primeval slime! stop