UNIT D: DNA REPLICATION By the end of the unit, you should know... 1. Name the four bases in DNA and describe the structure of DNA using the following terms: Nucleotide (sugar, phosphate, base), Complementary base pairing, Double Helix, and Hydrogen bonding 2. Describe DNA replication with reference to three basic steps: “Unzipping”, Complementary base pairing, and Joining of adjacent nucleotides. 3. Define recombinant DNA 4. Describe three uses for recombinant DNA 5. Compare and contrast the general structural composition of DNA and RNA VOCABULARY WORDS _____ Adenine _____ Base _____ Chromosomes _____ Complementary _____ Cytosine _____ Dehydration synthesis _____ Deoxyribose _____ DNA _____ DNA Polymerase _____ Double helix _____ Empirical formula _____ Evolution _____ Genome _____ Guanine _____ Hydrogen bonding _____ Helicase _____ Helix _____ Histone _____ Mutagen _____ Mutate _____ Nucleotide _____ Pentose Sugar _____ Plasmid _____ Polymer _____ Purine _____ Pyrimidine _____ Recombinant DNA _____ Replicate _____ Replication Bubble _____ Ribonucleic acid _____ Rosalind Franklin _____ Semi-conservative _____ Stem cell _____ Sugar Phosphate Backbone _____ Thymine _____ Unzip _____ Uracil _____ Watson and Crick UNIT D: DNA REPLICATION Interesting Facts: • • • • • • Humans share _____% of their DNA with bananas. Cells can contain ________ feet of DNA. If all the DNA in your body was put end to end, it would reach to the sun and back over ________ times. DNA in all humans is ________ % identical. It is about one tenth of one percent that makes us all unique, or about 3 million nucleotides difference. DNA can store ______ gigabytes of information per inch and is the most efficient storage system known to human. So, humans are better than computers!! In an average meal, you eat approximately _________________ cells or between ______________________ miles of DNA. It would take a person typing 60 words per minute, eight hours a day, around __________ years to type the human genome. So What Do We Know? DNA is composed of units called _____________________, which are composed of three submolecules: 1. _________________ (deoxyribose) 2. _________________ 3. _________________ (purine or pyrimidine) DNA is composed of two _________________ strands of nucleotides joined by ________________ _______: ____________ with ____________ They join with 2 hydrogen bonds _____________ with _____________ They join with 3 hydrogen bonds DNA twists into a ____________ Functions of DNA 1. DNA _____________________ machinery of a _______________ _______________________, and, therefore, DNA indirectly controls all of the functioning of all living things. 2. DNA ______________________________ of an individual 3. DNA ________________________ (change). This allows for new characteristics & abilities to appear which may help an individual to survive & reproduce (______________). 4. Self replication: DNA has the ability to ______________ _______________________. DNA REPLICATION 1. DNA replication is called ‘________________________’. 2. Semi-conservative replication is the process in which the _________________ of DNA _____________ and act as ______________ for the synthesis of duplicate strands of DNA. 3. One copy of a DNA molecule will split apart to make _______ complete copies of itself. Each new DNA molecule is made up of _______________ molecule and _____________ molecule. #1 STEPS TO DNA REPLICATION 1. __________________: The DNA molecule ‘Unzips’ as the _________________ between the base pairs are ______________. The enzyme __________________ causes this unzipping to occur. 2. _____________________ _______________________: Complementary __________ _____________________ to bond with the complementary bases on the DNA chain. 3. FORM _______________________________________: The nucleotides join as the sugars and phosphates bond to form a new backbone. This process occurs due to the enzyme ___________________ which also checks for ___________________ as it goes. #3 #2 4. This process continues along the primary chain until we have ________________________ of DNA molecules (assuming there have been no errors made). #4 ERRORS = MUTATION 1) Mutations can occur ___________ or through _______________ factors. Environmental ____________ include some _____________ (food additives, pesticides, plastics) and _____________ (X-rays to UV light). 2) A _________________ is a change of one or more ________________ in a single gene. There are 3 types. 1) Addition 2) Deletion 3) Substitution 3) ______________________: a mutation of ____________ of a chromosome. These __________ ________________. RECOMBINANT DNA Definition: __________________________________ ____________________________________________ 1. Gene ___________: add an extra copy of a gene (cows with huge teats to make double the milk) or deleting genes (removing the rotting hormone from tomatoes). 2. Gene _____________: repairing a gene (as in gene therapy). 3. Gene _____________: inserting genes from a different species to give a new function (as in making goats spider proteins in their milk or making bacteria that create human insulin). Recombinant DNA refers to DNA which has been altered by joining genetic material from two different sources!