DNA Deoxyribonucleic Acid “The Blueprint of Life” I. DNA Structure & Function

A. What is DNA? 1. Organic molecule 2. Nucleic acid

B.Where is it located ? 1. Nucleus 2. Makes up the Chromosomes DNA

Chromosomes in Nucleus

C. Structure of DNA 1. Nucleotides a. Phosphoric Acid b. Deoxyribose sugar c. Nitrogenous bases: Adenine-Thymine Guanine-Cytosine 2. Ladder Shape 3. Double strand, helix twist

NUCLEIC ACIDS are built from subunits called ____________________ Image by: Riedell NUCLEOTIDES SUGAR in DNA is ________________ deoxyribose

NITROGEN BASES in DNA _____________= A _____________ = G _____________ = C _____________= T ADENINE GUANINE CYTOSINE THYMINE

Ladder Shape (Sides & Rungs) Sides: Phosphoric Acid Sugar Phosphoric Acid Rungs: A-T T-A G-C C-G Sugar Acid Sugar Acid Sugar Acid Sugar  T-A   G-C   C-G   A-T  Sugar Acid Sugar Acid Sugar Acid Sugar

Watson & Crick’s Double helix:

D. What is DNA’s Function ? 1. Hereditary Instructions 2. Chemical code for every trait 3. “Blueprint” for making Proteins

Chromosome DNA Code: Genes = Segments of DNA Code for a trait Hair Color Eye Color

DNA Chromosome Code: Codons= Sets of 3 Nucleotides Code for Trait Acid Sugar-T-A-Sugar Acid Sugar-G-C-Sugar Acid Sugar-C-G-Sugar

DNA Chromosome Code: Like Morse Code: Hair = *** *- ** *-* Or DNA A-T A-T G-C C-G T-A C-G

DNA Replication Chromosomes double “S” part of Interphase Makes Identical copies 2N

E. Steps for DNA Replication: 1. DNA untwists 2. DNA unzips 3. Corresponding base pairs Line up In sets of 3 nucleotides “codons” or (triplets) 4. DNA reforms 5. 2 strands twist into helix Identical Strands

16 These animations(Audi o - Important) describe DNA replication: DNA replication1, DNA replication 2. DNA replication1, DNA replication 2.

RNA Ribonucleic Acid “DNA messenger & taxi” II. RNA Structure & Function

A. What is RNA? 1. Organic Molecule 2. Nucleic Acid 3. mRNA= messenger tRNA= transfer

B. Where is RNA located? 1. mRNA in nucleus & cytoplasm 2. tRNA only in cytoplasm mRNA tRNA

B. What is RNA’s structure? Acid Sugar-Base Acid Sugar-Base Acid Sugar-Base Acid Sugar-Base 1. Nucleotides= a. Phosphoric Acid b. Ribose sugar c. Nitrogenous Bases: Adenine-Uracil Guanine-Cytocine 2. Single Strand 3. No Twisted helix

Comparison of RNA & DNA: Acid Sugar-Base Acid Sugar-Base Acid Sugar-Base Acid Sugar-Base Acid Sugar-Base-Sugar Acid Sugar-Base-Sugar Acid Sugar-Base-Sugar Acid RNA DNA Ladder Deoxy- ribose Ribose Uracil Thymine

D. What are RNA’s functions: 1. mRNA= Copies the DNA code Deliveries message to Ribosome Protein Factories

Why not send the original DNA code out? DNA might be damaged! mRNA components are reused To copy more messages Original DNA mRNA copy

RNA function cont. 2. tRNA: in cytoplasm Picks up an amino acid “Taxis” the aa to the Ribosome protein factories tRNA Amino acid

III. Protein Synthesis Assembling Proteins from the DNA Instructions

A. Transcription : 1. mRNA is copied off of DNA 2. In nucleus 3. Steps: DNA untwists DNA unzips RNA codons line up

Transcription: mRNA has: Ribose sugar Uracil instead of thymine bases Nuclear membrane allows it to leave! DNA Code mRNA ATCGATCG UAGCUAGC

B. Translation = Decoding of the message (mRNA Code) Into a protein By the ribosome factories

C.Translation 1. mRNA arrives at the Ribosome 2. tRNA picks up an amino acid 3. tRNA delivers the aa to the ribosome 4. aa are assembled into proteins U A G C G C U A mRNA code tRNA taxi

2. Peptide bond forms 3. tRNA leaves ribosome 4. Chain of amino acids grows 1. tRNA delivers amino acid

Summary: DNA Replication: Make duplicate DNA In nucleus Copy the chromosomes For Mitosis Protein Synthesis: 1. Transcrition: Make mRNA From DNA 2. Translation: Make protein Off of mRNA code Using amino acids