2VocabularyDNA (Deoxyribonucleic Acid) – A nucleic acid that contains a deoxyribose sugar. Is a long molecule that is made up of units called nucleotidesNucleotides – Monomer of nucleic acids made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base. The THREE basic units of DNA
3DNADNA contains the genetic code of an organism, with traits expressed through proteins made by cellsDNA can be found in the nucleus and mitochondria.
9Nitrogen BasesThe nitrogen bases of DNA from complementary base pairs with adenine pairing with thymine, and cytosine pairing with guanineThe nitrogen bases spell out a coded message.
10Quiz: DNA 4. What does a double helix look like? 5. What does DNA stand for?Degraded Nucleic AcidDeoxyribose Nitrogenous AcidDeoxyribonucleic acid6. What was Rosaline Franklin known for?Finding out the structure of DNATaking pictures of DNA with a x-rayDiscovering the existence of DNA7. What are Watson and Crick known for?Name the three parts of a nucleotide.Find the complimentary strand for the following DNA strand:ATTTCGTGCAGA??????????????3. Do purines of pyrimidines have two rings?
12ReplicationDNA replication happens in the Synthesis phase of the cell cycleHappens BEFORE mitosisReplication
13DNA ReplicationWhen DNA is replicated or copied, it results in two IDENTICAL strands.Replication happens in three simple steps:The two original strands of DNA are separated by helicaseDNA Polymerase adds complimentary nucleotides to each strand.Two DNA molecules form that are identical to the original.
14Step 1: DNA SeparatesThe DNA helix unwinds with the help of enzymes called DNA helicases.Nucleotide bases separate at an area called the replication fork.
15Step 2: DNA Polymerase adds nucleotides NewStrandsformingAt the replication fork, DNA Polymerase move along each DNA strand and add complimentary nucleotides.Adenine with thymineCytosine with GuanineTwo new strands begin to form.
16Step 3: Two DNA Molecules form DNA polymerase continues adding nucleotides until all the DNA has been copied.DNA polymerase detaches and two new identical DNA molecules are left.
17DNA Polymerases other role… Because errors can occur in DNA replication, DNA polymerase also has a role in fixing the new DNA strands.DNA polymerase fix mismatched nucleotides
18DNA Replication in Eukaryotes Eukaryotes have one long DNA strand for each chromosomesemi conservative model (new double helix has 1 parent strand + 1 new daughter strand)replication forkParent strandDaughter strand
19DNA REPLICATION in Prokaryotes Prokaryotes have one circular DNAreplication fork
20PASTA DNA LAB Follow Procedure I to make a model of DNA. Follow the directions EXACTLY the same EXCEPT instead of tying the noodles on string, GLUE THEM on to notebook paper.In Procedure two, make a model of DNA “unzipping” or separating on another piece of paper.The show 2 identical DNA strands that were made.They should look EXACTLY like the first DNA strand.
23Transcription & Translation Making Proteins……involves a series of steps.Transcription & TranslationmRNA is made in transcription.Protein is made in translation.
24RNA RNA differs from DNA in three ways: Single stranded Has uracil instead of thymine nitrogen basesContains ribose sugar instead of deoxyribose in its backbone.
25Transcription in 3 easy steps Step 1 Transcription starts when RNA polymerase binds to a specific DNA sequence that tells cell to START transcription.Remember, A,T,C, and G “spell” out messages.START
26Next, the RNA polymerase unwinds and separates the DNA. Step 2Next, the RNA polymerase unwinds and separates the DNA.
27Step 3Last, RNA polymerase adds complimentary RNA nucleotides to the DNA strand.The polymerase adds:cytosine to guanine and guanine to cytosineadenine to thymine BUT uracil to adenine.
28Why make Messenger RNA? Messenger RNA When a cell needs a protein, mRNA is created.mRNA carries instructions for building a protein and delivers it out side of the nucleus.Messenger RNA
29ACTIVITY! ^_^Your objective is to take the following DNA strands and transcribe them into RNA.Materials: Pipe cleaners and colored beads.Green: Adenine; Yellow: Guanine; Red: Thymine; Blue: Cytosine; White: Uracil.Procedure: Transcribe the SECOND STRAND of each of the following DNA sequences.Make your DNA and RNA using the pipe cleaner given and the colored beads.Show me your RNA strand. If it is correct then turn into me your RNA sequences written down on paper. Return the beads and pipe cleanersDNA sequence oneStrand one: ATGCTGAAGStrand two: TACGACTTCDNA sequence threeStrand one: TATCGTAGTStrand two: ATAGCATCADNA sequence twoStrand one: CGCTTAAACStrand two: GCGAATTTGDNA sequence fourStrand one: ATGCAATAGStrand two: TACGTTATC
31Vocabulary Amino acids: make PROTEINS Ribosomal RNA are part of the structure of ribosomes.They hold the mRNA and two tRNAs in place during translationtRNA molecules are single strands of RNA that carry a specific amino acid with them.Amino acids: make PROTEINS
32Vocabulary Codons: instructions written as three nucleotide sequences. Each codon corresponds to an amino acid or start or stop signal.Ex:GUA ValineUUC Phenylalanine
33To build a protein……we must move on to our next step that moves our RNA out of the nucleus and into the cytoplasm.
34TranslationmRNA moves into the cytoplasm where it binds with a rRNA, and a tRNA carrying an amino acid.The codon is ready to receive the next tRNA and its amino acid
35PeptidebondOnce mRNA is holding two tRNAs, each carrying specific amino acids, enzymes form peptide bonds between the two amino acids.The tRNA in the first site prepares to detach, leaving behind the amino acid.
36Another tRNA fills in the empty site. This process repeats until a STOP codon is reached (UAG, UAA, or UGA).The amino acid chain is release, forming into a new protein.
37Amino acids form protein. TranscriptionAmino acids form protein.