Nucleic Acids Information storage AP Biology Nucleic Acids
Nucleic Acids Information storage AP Biology
Nucleic Acids § Function: u genetic material 1. stores information w genes w blueprint for building proteins n DNA RNA proteins 2. transfers information w blueprint for new cells w blueprint for next generation AP Biology proteins
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 [have different N bases] 1. purines § double ring N base § adenine (A) § guanine (G) 2. pyrimidines AP Biology § § single ring N base cytosine (C) thymine (T) uracil (U)
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
Directionality of DNA § You need to PO 4 nucleotide number the carbons! u it matters! N base 5 CH 2 This will be IMPORTANT!! 4 O 3 AP Biology 1 ribose OH 2
The DNA backbone § Putting the DNA backbone together u refer to the 3 and 5 ends of the DNA § the last trailing carbon Sounds trivial, but… this will be IMPORTANT!! 5 PO 4 5 CH 2 4 base O 1 C 3 O –O P O O 5 CH 2 2 base O 4 1 2 3 OH AP Biology 3
Bonding in DNA 5 hydrogen bonds 3 covalent phosphodiester bonds 3 …. strong or weak bonds? Why? Remember Hydrogen Bonds A-T (2) and C-G (3) AP Biology 5
DNA molecule § Shape: § Double helix u H bonds between bases join the 2 strands § A : : T § C : : G H bonds? Why is this important? AP Biology
Another interesting note… § ATP Adenosine triphosphate u modified nucleotide § adenine (AMP) + Pi + AP Biology +
3 differences between DNA and RNA DNA structure § Has deoxyribose as a sugar § Double strand – double helix § Has thymine as a base AP Biology RNA structure § Has ribose as a sugar instead of deoxyribose § Is generally singlestranded § Has uracil instead of thymine
Scientists: • Erwin Chargaff – studied amounts of • • nitrogenous bases in DNA (base pair rule) Rosalind Franklin – 1952 – X-ray diffraction to get pattern from structure of DNA - Responsible for the molecular structure James Watson & Francis Crick – 1953 – published model and paper on DNA structure as a double helix AP Biology
- Slides: 13