Nucleic acids AP Biology 2006 2007 Nucleic Acids
Nucleic acids AP Biology 2006 -2007
Nucleic Acids Information storage AP Biology 2006 -2007
Nucleic Acids § Function: u genetic material § stores information w genes w blueprint for building proteins n DNA RNA proteins § transfers information w blueprint for new cells w blueprint for next generation AP Biology proteins
G T A AP Biology A C G T C G A T C A
Nucleic Acids § Examples: u RNA (ribonucleic acid) § single helix u DNA (deoxyribonucleic acid) § double helix § Structure: u AP Biology monomers = nucleotides DNA RNA
Nucleotides § 3 parts nitrogen base (C-N ring) u pentose sugar (5 C) u § ribose in RNA § deoxyribose in DNA u phosphate (PO 4) group Are nucleic acids charged molecules? AP Biology Nitrogen base I’m the A, T, C, G or U part!
Types of nucleotides § 2 types of nucleotides different nitrogen bases u purines u § double ring N base § adenine (A) § guanine (G) u AP Biology pyrimidines § § single ring N base cytosine (C) thymine (T) uracil (U) Purine = AG Pure silver!
Nucleic polymer § Backbone sugar to PO 4 bond u phosphodiester bond u § new base added to sugar of previous base § polymer grows in one direction u N bases hang off the sugar-phosphate backbone Dangling bases? Why is this important? AP Biology
Pairing of nucleotides § Nucleotides bond between DNA strands H bonds u purine : : pyrimidine u A : : T u § 2 H bonds u G : : C § 3 H bonds Matching bases? Why is this important? AP Biology
DNA molecule § Double helix u H bonds between bases join the 2 strands § A : : T § C : : G H bonds? Why is this important? AP Biology
Copying DNA § Replication u 2 strands of DNA helix are complementary § have one, can build other § have one, can rebuild the whole Matching halves? Why is this a good system? AP Biology
When does a cell copy DNA? § When in the life of a cell does DNA have to be copied? u cell reproduction § mitosis u gamete production § meiosis AP Biology
DNA replication “It has not escaped our notice that the specific pairing we have postulated immediately suggests a possible copying mechanism for the genetic material. ” James Watson Francis Crick 1953 AP Biology
1953 | 1962 Watson and Crick … and others… AP Biology
Maurice Wilkins… and… AP Biology 1953 | 1962
Rosalind Franklin (1920 -1958) AP Biology
Interesting note… § Ratio of A-T: : G-C affects stability of DNA molecule u u 2 H bonds vs. 3 H bonds biotech procedures § more G-C = need higher T° to separate strands u high T° organisms § many G-C u parasites § many A-T (don’t know why) AP Biology
Another interesting note… § ATP Adenosine triphosphate u modified nucleotide § adenine (AMP) + Pi + AP Biology +
HELIX AP Biology
Macromolecule Review AP Biology 2006 -2007
Carbohydrates § Structure / monomer u monosaccharide § Function energy u raw materials u energy storage u structural compounds u glycosidic bond § Examples u AP Biology glucose, starch, cellulose, glycogen
Lipids § Structure / building block u glycerol, fatty acid, cholesterol, H-C chains § Function energy storage u membranes u hormones u § Examples u AP Biology ester bond (in a fat) fat, phospholipids, steroids
Proteins § Structure / monomer amino acids u levels of structure u § Function enzymes u transport u signals u defense u structure u receptors u peptide bond § Examples u AP Biology digestive enzymes, membrane channels, insulin hormone, actin
Nucleic acids § Structure / monomer u nucleotide § Function u information storage & transfer § Examples u AP Biology DNA, RNA phosphodiester bond
Let’s build some DNA, baby! AP Biology
Ghosts of Lectures Past (storage) AP Biology 2007 -2008
Building the polymer AP Biology
RNA & DNA § RNA u single nucleotide chain § DNA u double nucleotide chain § N bases bond in pairs across chains u spiraled in a double helix § double helix 1 st proposed as structure of DNA in 1953 by James Watson & Francis Crick (just celebrated 50 th anniversary in 2003!) AP Biology
Information polymer § Function u series of bases encodes information § like the letters of a book u stored information is passed from parent to offspring § need to copy accurately u stored information = genes § genetic information Passing on information? Why is this important? AP Biology
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