Presentation on theme: "DNA and RNA DNA was the first three-dimensional Xerox machine – Kenneth Ewart Boulding."— Presentation transcript:
1 DNA and RNADNA was the first three-dimensional Xerox machine – Kenneth Ewart Boulding
2 Essential StandardsBio.3.1 Explain how traits are determined by the structure and function of DNA.Bio Explain the double-stranded, complementary nature of DNA as related to its function in the cell. Bio Explain how DNA and RNA code for proteins and determine traits. Bio Explain how mutations in DNA that result from interactions with the environment (i.e. radiation and chemicals) or new combinations in existing genes lead to changes in function and phenotype.Bio.3.2 Understand how the environment, and/or the interaction of alleles, influences the expression of genetic traits.Bio Explain the role of meiosis in sexual reproduction and genetic variation. Bio Predict offspring ratios based on a variety of inheritance patterns (including dominance, co-dominance, incomplete dominance, multiple alleles, and sex-linked traits). Bio Explain how the environment can influence the expression of genetic traits.Bio.3.3 Understand the application of DNA technology.Bio Interpret how DNA is used for comparison and identification of organisms. Bio Summarize how transgenic organisms are engineered to benefit society. Bio Evaluate some of the ethical issues surrounding the use of DNA technology (including cloning, genetically modified organisms, stem cell research, and Human Genome Project).
3 Structure and Function of DNA We have come a long way on that old molecule [DNA].Structure and Function of DNA
4 Brief Review: Nucleic acid Nucleotides What type of macromolecule is DNA or RNA?What monomer makes up DNA?What are the components of this monomer?What organelle houses DNA?What is the division of this organelle called?What part of the cell cycle is DNA replicated in?Nucleic acidNucleotidessugar, phosphate, nitrogenous baseNucleusMitosisInterphase, S phase
5 How was DNA discovered?James Watson and Francis Crick won the race to find the structure of DNA, and a Nobel prize in 1962Maurice Wilkins was later also added to the prize list for his contributions
6 How was DNA discovered? cont’d Wilkins was also working on the problemRosalind Franklin worked in Wilkins lab taking X-ray diffraction pictures of DNAHer pictures supported the DNA structureShe was never given credit as she died before Wilkins name was added due to X-ray exposure
7 How is DNA structured? DNA is double stranded Backbone made of alternating phosphates and deoxyribose sugarsContains 4 bases (“rungs of the ladder”)Adenine (A)Thymine (T)Cytosine (C)Guanine (G)Looks like a twisted ladder
8 How is DNA studied? Genetics –branch of biology that studies heredity Heredity – how traits are passed from parent to offspringTraits – characteristics of an organismex. body shape, cell shape, proteins producednucleic acids contain information that determine traitsmade of?
9 What are nucleic acids? Macromolecules made of nucleotides nucleotides are made up of a sugar backbone, a phosphate, and a nitrogenous basecells contain 2 typesDNA (deoxyribonucleic acid)RNA (ribonucleic acid)Both contain 5 carbon sugars arranged in a ring
10 What is the function of DNA? Carries genetic informationinstructions for cellular activity and making necessary proteinsWhat are the different structures of proteins?How do those structures interact?
11 Where is DNA? Where do you find DNA in prokarotes? What are small circular pieces of DNA in prokaryotes called?Where do you find DNA in eukaryotes?In eukaryotes, DNA is coiled into structures called chromosomesWhat is DNA normally when it is uncoiled?chromatin
12 How is DNA structured? made of linked nucleotides nucleotides are all the same except with a different nitrogenous baseACTGshaped like a twisted ladder = double helixstrands of alternating deoxyribose sugars and phosphatesrungs are one of four bases
14 How do the bases of DNA work? Chargaff’s rule:A always pairs with TC always pairs with GThese are called complementary base pairsHeld together by weak hydrogen bondssequence of bases stores genetic information
16 How does DNA determine traits? traits are based on proteins produced in an organismproteins are not made directly by DNAinformation is copied from DNA to an RNA molecule (transcription)RNA carries information to ribosomes (translation)What do these make?What to they make proteins from?
17 Why is DNA replicated? Cells are alive so what must they do? During the cell cycle, when is DNA replicated?DNA is replicated so that each daughter cell has identical DNA to the parent cell
18 How is DNA replicated?Step 1: helicase enzymes break H bonds and unwinds DNA down the middle2 going in opposite directionsStep 2: DNA polymerase enzymes from cytoplasm join complementary base pairs to make a matching strandsynthesized from 5’ to 3’
19 What is the result of DNA replication? 2 strands of identical DNAeach strand is half old DNA and half new DNAsemiconservative processBuild a DNA Molecule
20 Assignment! DNA replication worksheet Use your notes to help you with the information… IT IS ALL HERE
21 What are chromosomes?chromosomes – are structures of containing genetic information passed down from parent to offspringDNA is a long molecule, nucleus of a human contains over a meter of DNA!coiled to save space so DNA can fit in the nucleus
22 How are chromosomes and genes related? Each specie has a specific number of chromosomessegments of chromosomes (or DNA) that code for proteins are called genesmany genes on 1 chromosomeorganisms have many more inherited genes that chromosomes
23 How is DNA compared between species? Genetic information varies between speciesDNA of all organisms have some things in commonThe more common things they share the more closely related they areSimilarity determined by how many genes are shared AND how alike those genes areSmaller variations are also present among members of the same species
24 Assignment! DNA extraction You will need: strawberry ziploc bag DNA extraction buffercheeseclothfunneltest tubestirring rodalcohol
26 Brief Review What are traits determined by? What are proteins made of? Where do instructions to make proteins come from?What type of macromolecule is RNA?So what are the monomers of RNA?Proteins!Amino Acids!DNA!Nucleic Acid!Nucleotides!
27 What is the structure of RNA? Single strandedRibose sugar and phosphate backboneNucleotides, which are made of what?Adenine (A)Uracil (U)Guanine (G)Cytosine (C)C pairs with GA pairs with U
28 How are proteins made? RNA copies information from DNA (transcription) RNA leaves the nucleus and takes information to the ribosomeRibosome reads RNA and assembles protein (translation)
29 What types of RNA make proteins? Messenger RNA (mRNA) – carries information from the nucleus to the proteinTransfer RNA (tRNA) – carries amino acids to the ribsomeRibosomal RNA (rRNA) – makes part of the ribosme
30 What exactly is transcription? Instructions to make proteins are encoded on DNA in nucleotide basesBases are arranged in triplets (groups of 3)64 possible triplets (4x4x4)transcription – uses a DNA template to make a complementary RNA strand
31 How is transcription different than DNA replication? RNA Polymerase – enzyme that copies RNA from DNA, DNA Polymerase replicates DNAOnly produces 1 strand of nucleotidesUracil is used in place of thyminetranscription
32 How does transcription happen? Cell releases chemical signals to start transcriptionPortion of DNA to be used for transcription is separatedRNA polymerase binds at promoter region of DNAComplementary nucleotides are added to RNA strandmRNA is producedDNA reconnects
33 Where does mRNA go?From the nucleus to the cytoplasm to a ribosome (translation)Where you find ribosomes in a eukaryotic cell?Instructions on mRNA arranged in codons – groups of 3 consecutive basesa codon codes for a certain amino acid or the end of a protein
34 How are codon charts used? Practice:AUGGUC ACCGACUCGUUAAUCAAUCUAAAAGUAGGUAGACAUGUGGAGGGGUAAFind the first letter in the row “first base”Find the second letter in the row “second base”Find the third letter in the row “third base”Find where the lines intersect = amino acid
35 Assignment! Complete the transcription translation worksheet Complete the DNA coloring worksheet
36 What exactly is translation? Translation – conversion of the information on mRNA into a sequence of amino acids to make a proteinbegins after mRNA moves out of the nucleus into the cytoplasmmRNA joins with a ribosomeinformation translated into codons and to amino acids
37 How does the amino acid chain form? Transfer RNA (tRNA) – carries amino acids to mRNA in the ribosomemRNA codons join with anticodons, complementary bases to codons found on tRNASequence of the anticodon determines the amino acid it carries - based on shape
38 What does the ribosome do? Ribosomes assembles amino acid into proteinRibosomal RNA (rRNA) – makes up part of the ribosome structure and assists in translation
39 How does tRNA work in the ribosome? up to 2 tRNA molecules can attach to mRNA at oncetRNA enters through the A site (aminoacyl) bringing amino acidtRNA moves to P site (peptidyl) where the peptide bond is formed between amino acidstRNA moves to E site (exit)
40 What happens to tRNA when it leaves the ribosomes? tRNA releases from E site after amino acid is attached so another anticodon can be attached to mRNAfree tRNA bonds with free floating amino acid in the cytoplasm and can be reusedRibosome continues to attach tRNA until a stop codon is reached
41 Assignment!With your group complete the paper pencil transcription protein synthesis labYou will needquestion guidetemplatelong paperglueAt least 1 page of each basetRNAsCodon chartscissorsGTP capHonors’ – design your own ribosome with A, P, and E sites
42 What is gene expression? What is a gene?main function of a gene is to control production of proteingene expression – process by which information carried in genes is used to make protein or direct cell activities
43 How does gene expression affect differentiation? multicellular organisms have many cells with the same DNACells are not identical due to differences in how genes are expressedonly a fraction of genes are expressed at a given timeGene regulation – complex mechanism - determines if a gene is expressed or not
44 Do cells produce different amounts of protein? Yes, the proteins produced depend in part on the environmentcells responding to an injury by producing proteins for repairantibodies produced when a pathogen is detectedlength of poly A tail at the end of mRNA determines how long it can survive in cytoplasm
45 What happens when errors occur? Producing too much or too little protein, producing at the wrong time can lead to problemsoverproduction of some proteins lead to cancerCancer occurs when the cell cycle is disrupted causing old or damaged cells to reproduce faster than healthy cells
Your consent to our cookies if you continue to use this website.