SB2. Students will analyze how biological traits are passed on to successive generations. a. Distinguish between DNA and RNA. b. Explain the role of DNA in storing and transmitting cellular information. d. Describe the relationships between changes in DNA and potential appearance of new traits including Alterations during replication. Insertions Deletions Substitutions Mutagenic factors that can alter DNA. High energy radiation (x-rays and UV) Chemical DNA and RNA 50%Humans share 50% of their DNA with bananas Cells can contain 6-9 feet of DNA. If all the DNA in your body was put end to end, it would reach to the sun and back over 600 times. 99.9DNA in all humans is 99.9 percent identical. It is about one tenth of one percent that makes us all unique, or about 3 million nucleotides difference. 25DNA can store 25 gigabytes of information per inch and is the most efficient storage system known to human. So, humans are better than computers!! 55,000,000 63,000 to 93,000In an average meal, you eat approximately 55,000,000 cells or between 63,000 to 93,000 miles of DNA. 50It would take a person typing 60 words per minute, eight hours a day, around 50 years to type the human genome. In the next 60 seconds your body will produce enough new DNA that if it was linked together, it would stretch 100,000 km NUCLEOTIDES DNA is composed of units called NUCLEOTIDES, which are composed of three sub-molecules: 5-Carbon Sugar 1. 5-Carbon Sugar (deoxyribose) Phosphate 2. Phosphate Nitrogen Base 3. Nitrogen Base (purine or pyrimidine) complimentary hydrogen bonds: DNA is composed of two complimentary strands of nucleotides joined by hydrogen bonds: Adenine Thymine Adenine with Thymine (A-T or T-A) 2 They join with 2 hydrogen bonds Cytosine Guanine Cytosine with Guanine (C-G or G-C) 3 They join with 3 hydrogen bonds double helix DNA twists into a double helix https://www.dnalc.org/resources/3d/23-dna-unzip.html https://www.dnalc.org/resources/3d/07-how-dna-is-packaged-basic.html directs thecell to make specific proteins 1.DNA directs the machinery of a cell to make specific proteins, and, therefore, DNA indirectly controls all of the functioning of all living things. stores the hereditary information 2. DNA stores the hereditary information of an individual has the ability to mutate EVOLUTION 3. DNA has the ability to mutate (change). This allows for new characteristics and abilities to appear which may help an individual to survive and reproduce (EVOLUTION). make copies of itself 4. Self replication: DNA has the ability to make copies of itself semi-conservative 1.DNA replication is called semi-conservative. original strandsremain intact templates 2. Semi-conservative replication is the process in which the original strands of DNA remain intact and act as templates for the synthesis of duplicate strands of DNA. two half of the oldhalf of a new 3. One copy of a DNA molecule will split apart to make two complete copies of itself. Each new DNA molecule is made up of half of the old molecule and half of a new molecule. https://www.dnalc.org/resources/3d/03-mechanism-of-replication-basic.html Replication the copying of a DNA strand 1.Helicase enzyme binds to the DNA and unzips it. 2.DNA polymerase binds to the DNA at the replication fork. 3.DNA polymerase adds new bases to both strands, according to the base-pairing rules. 4.The enzymes release from the DNA and the new strands zip and wind back up. Replication Ribonucleic acid -single stranded -has uracil instead of thymine -ribose instead of deoxyribose The process by which RNA is made. Takes place inside the nucleus. https://www.dnalc.org/resources/3d/12-transcription-basic.html Steps of transcription 1.RNA polymerase binds to the DNA molecule and unwinds and unzips it. 2.RNA polymerase adds new RNA bases along the DNA strand, according to the rules. Wherever there is C, it adds G. Wherever there is T, it adds A. Wherever there is A, it adds U. 3.The RNA detaches from the DNA. 4.The DNA winds up and zips back up. Three different types of RNA are made by transcription. mRNA messenger RNA (responsible for carrying the message) tRNA transfer RNA (carries amino acids) rRNA ribosomal RNA (found in ribosomes) The process by which proteins are made. Takes place in the cytoplasm. https://www.dnalc.org/resources/3d/15-translation-basic.html 1.mRNA reaches the ribosome 2.The ribosome reads the mRNA codons 3.tRNAs with matching anticodons come to the ribosome 4.tRNAs carry amino acids 5.The ribosome assembles the amino acid chain according to the mRNA code 6.The new protein (amino acid chain) detaches from the ribosome Translation is the last step of gene expression. The genetic code matching the mRNA nucleotides to the amino acid sequence. The chart always refers to the mRNA codons. What is the amino acid sequence for the following mRNA chain? GUU ACC UAU UCA UAA Val - Thr - Tyr - Ser - stop naturally environmental 1)Mutations can occur naturally or through environmental factors. mutagens chemicals radiations Environmental mutagens include some chemicals (food additives, pesticides, plastics) and radiations (X-rays to UV light). gene mutation nucleotides 2) A gene mutation is a change of one or more nucleotides in a single gene. There are 3 types. a) Addition b) Deletion c) Substitution GENE MUTATIONS Deletion Deletion: one nucleotide base is left out. All of the amino acids after a deletion will be wrong, so SHAPE and FUNCTION of protein are altered. Ex. cystic fibrosis Insertion Insertion: one extra nucleotide base is added. This will also change the entire amino acid sequence of the protein, so SHAPE and FUNCTION of protein are altered. Ex. Crohns disease Substitution Substitution: when single bases or short pieces are replaced with one another. Ex. muscular dystrophy; sickle-cell anemia Insertions and deletions are also called frameshift mutations because they change the way the subsequent amino acids are read. Chromosomal mutationsall or part affect many genes 3. Chromosomal mutations: a mutation of all or part of a chromosome. These affect many genes. crossing over Example #1: crossing over where one part of a chromosome changes places with another. This can cause extra pieces, missing pieces, or the exchange of pieces of chromosomes. Example #2: non-disjunction non-disjunction = extra chromosomes or missing chromosomes due to mistakes made during meiosis.