1 Lesson 7e: Nucleic acids: Information moleculesHelix – twisted Re - again Lesson 7e: Nucleic acids: Information molecules

2 Nucleic Acids Examples DNA DeoxyriboNucleic Acid RNA RiboNucleic Acid

3 Nucleic Acids Function: genetic material stores informationgenes blueprint for new cells blueprint for next generation transfers information blueprint for building proteins DNA  RNA  protein DNA proteins

4 A T C G Structure of DNA 1:14 DNA folding to make Chromosomes 2:21

5 Nucleic acids 5 different nucleotides Building block = nucleotidesnucleotide – nucleotide – nucleotide – nucleotide 5 different nucleotides different nitrogen bases A, T, C, G, U Nitrogen bases I’m the A,T,C,G or U part! phosphate sugar N base

6 Nucleotide chains Nucleic acids nucleotides chained into a polymer DNAphosphate sugar N base Nucleotide chains Nucleic acids nucleotides chained into a polymer DNA double-sided double helix A, C, G, T RNA single-sided A, C, G, U phosphate sugar N base strong bonds phosphate sugar N base phosphate sugar N base

7 DNA Double strand twists into a double helixweak bonds between nitrogen bases join the 2 strands A pairs with T A :: T C pairs with G C :: G the two strands can separate when our cells need to make copies of it It’s a helix or B sheet within a single region. Can have both in one protein but a specific region is one or another

8 Copying DNA Replication 2 strands of DNA helix are complementarymatching have one, can build other have one, can rebuild the whole when cells divide, they must duplicate DNA exactly for the new “daughter” cells Why is this a good system?

9 Newly copied strands of DNADNA replication Copying DNA pairing of the bases allows each strand to serve as a pattern for a new strand The greatest understatement in biology! Newly copied strands of DNA

10 Watson and Crick … and others…1953 | 1962 Watson and Crick … and others…

11 Sample Question Which of the following is true of a nucleic acid? a. Nucleotides are made of a 5-carbon sugar, a nitrogen base, and a lipid. b. DNA and RNA are examples of nucleic acids that are rarely seen in living things. c. Nucleic acids are made of repeating units called lipids. d. Nucleic acids store important information about cell division and the manufacturing of proteins.

12 Flash: Biology__The_Science_of_Life__DNA__The_Master_Molecule_of_LifeBefore reading the choices, recall what you know about the topic. Then look for the answer. TEST TIPS!