th period DNA means deoxyribonucleic acid early 1900snot thought very important because so simple DNA is inherited from your parentsbasis for genetics discovered in 1940s Mutations mess up DNA amp can cause birth defects or diseases ID: 932119
Download Presentation The PPT/PDF document "What do I know about DNA? 4" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
What do I know about DNA? 4th period
DNA means deoxyribonucleic acid early 1900’s—not thought very important because so simpleDNA is inherited from your parents—basis for genetics discovered in 1940’sMutations mess up DNA & can cause birth defects or diseases discovered in 1970’sDNA is passed in sex cells discovered in 1950’sDNA makes up chromosomes-we have 20 somethingIt’s twisty—like a twisted ladder—called a double helix Discovered 1951 nobel prize
Slide2What do I know about DNA? 5th period
DNA is found in the nucleus You can identify a person by DNA analysis—unique for every personDouble helix structureDNA is needed to make proteinsDNA controls everything happening in cellEach child’s DNA comes from the parents basis of genetics parent’s got it from their parents sex passes it on
Slide3DNA Structure and Replication Notes
November 19, 2015
Slide4http://www.hhmi.org/biointeractive/double-helix
Who discovered dna?
Slide5Questions 4th period
Why do older women have more babies with birth defects?Why can blond mom and dad have red head kid?
Slide6DNA Structure Notes
http://www.hhmi.org/biointeractive/chemical-structure-dna
Slide7Extract DNA from a strawberryhttps
://www.youtube.com/watch?v=vPGKv53zSRQPour DNA extract solution (dishwashing soap, NaCl, distilled water) into a sealable plastic bag with a strawberry. Seal … no leaks!Gently mash strawberry until it’s a smooth solution. (5 minutes)Line a funnel w/ cheesecloth, then filter mashed strawberry into a tube; mash juice but not chunks through cheesecloth. Throw out cloth; wash funnel. Gently layer (pour slowly down side of angled tube) cold alcohol onto top of strawberry solution. Watch 2 minutes as strands of DNA (chromosomes, each millions of nucleotides long!) rise into the top layer. Pull out some of the DNA with a plastic pipet, then add it to the class flask that is filled with alcohol (to make the DNA easier to see)Pour remaining solution down sink, rise tubes/stoppers & place in dish tray.
Slide8I. Functions of DNA = “Blueprint of Life”
Storing InformationStore the genes that code for basic instructions for cells and cell parts, physical traits, diseases, etc.Eye color, blood type, skin color, diabetes, etc.Copying InformationBefore a cell divides, it must make a copy of every one of its genesProcess called DNA replicationTransmitting Information Genes are transmitted from one generation to the nextDNA must be carefully sorted and passed along during mitosis and meiosis
Slide9II. Basics of DNA Structure
DNA - stands for deoxyribonucleic acidB. double-strandedC. 3-D model is called = double helixDiscovered by James Watson & Francis Crick (Received Nobel Prize 1962) with the help of Rosalind Franklin’s data
Slide10Long double helices of DNA, each millions of nucleotides long, form chromosomes. Each chromosome contains hundreds of genes. Humans cells have 46 chromosomes.
Slide11III. Nucleic Acid Structure
DNA is a type of molecule called a nucleic acidThe building blocks of DNA are known as nucleotidesAll nucleotides have three “parts” in common: PhosphateSugar (deoxyribose) Nitrogen
base
Slide12NUCLEOTIDE
Slide13B. Nitrogen Bases
Four types:AdenineGuanineCytosineThymine2. The order of these bases = the genetic code!
Slide14Complementary Base Pairing
A-T and C-G pairs are the only ones physically possibleHydrogen bonds between nitrogen bases2. Adenine and Thymine must form two hydrogen bonds to be stable while Guanine and Cytosine
must form
three
hydrogen bonds
Slide15LET’S PRACTICE! Write the complementary sequence of bases to this strand of DNA.
A T C C G G A T
Slide16DNA Structure (more details)
Sugar/Phosphate “Backbone”Sides of ladderCovalent bond between sugar and phosphateNitrogen Bases in centerSteps of ladderHydrogen bond between Nitrogen basesDouble Helix Twisted ladderAnti-paralleltwo strands of DNA run in opposite directions
Slide17DNA is Anti-ParallelThe two strands
of DNA run inopposite directions This allows for the bases to come in contact at the center of the molecule
Slide18Slide19DNA Replication Notes
November 19, 2015
Slide20I. DNA Replication
PurposeAll cells must divide to make new cellsBefore cell division DNA is replicated so it can be passed to the new cellThis process of copying the DNA in the chromosomes is called DNA ReplicationWithout this process, new cells would have only half the DNA of their parents
Slide21Each new DNA molecule has one original “parent” strand and one new strand!
Slide22B. Process of DNA Replication
Occurs in the nucleus prior to any cell divisionEnzyme is used to “unzip” or “unwind” the DNA into two single strandsEnzyme breaks hydrogen bonds between nitrogen basesThis occurs along several sections of the whole molecule of DNA
Enzyme
Slide23B. Process of DNA Replication (cont.)
Another enzyme, DNA polymerase, bonds a complementary nucleotide to each strand of template DNANitrogenous bases pair upA – TC - GEach strand is replicated in opposite directions, since DNA is anti-parallelProcess continues until the entire strand of DNA has been unzipped and replicated
Slide24Slide25B. Process of DNA Replication (cont.)
As a result, you create two new molecules of DNA that are identical to the original piece of parent DNAEach DNA molecule has a new strand of DNA and an old strand of DNA (parent DNA)