LECTURE 3 MICROEVOLUTION PART 1 DNA TODAYS OBJECTIVES

LECTURE 3: MICROEVOLUTION PART 1 DNA TODAY’S OBJECTIVES: • Identify building blocks of DNA • Describe DNA structure and the rules to base pairing in DNA

What is DNA? • How does DNA make each of these items look/function differently?

What are the building blocks of DNA? • DNA: – Deoxyribonucleic acid • Polymer (nucleic acid)made up of monomers (nucleotides) • Nucleotides – building blocks of DNA – Only 4 make up DNA

What is the structure of a Nucleotide? • Nucleotide: – 3 parts • Ring shaped sugar (deoxyribose) • Phosphate group (P surrounded by 4 O) • Nitrogenous base (nitrogen and carbon ring/s with functional groups)

What are the Nitrogenous bases? • Nitrogenous bases: – 4 bases in DNA • Pyrimidines (single ring) – Thymine (T) – Cytosine (C) • Purines (double ring) – Adenine (A) – Guanine (G)

What are the Nitrogenous bases?

What are DNA strands? • DNA is double stranded • Each Strand is a line of nucleotides bonded together • Nucleotides are joined together by covalent bonds – Sugar group of one nucleotide is bonded to phosphate group of another

What is the structure of DNA? • DNA: – Double helix • Sugar-phosphate group on outside • Bases on the inside – Complimentary base pairs • Bases of the two strands bond together in specific way – A-T – C-G

• • What does this mean? ATTGCGCCTTTTCG TAACGCGGAAAAGC What would the complementary strand look like?

What is a gene? • Gene: – Function of gene is to code for a specific polypeptide – Language of genes is a specific nucleotide sequence • Each gene is like a sentence/with the bases being the letters

What is the Information flow of DNA? • Gene (portion of DNA) is copied – TRANSCRIPTION • m. RNA copies a portion of DNA strand (gene) • Leaves nucleus to direct making of protein • The m. RNA is read to make specific amino acid sequences – TRANSLATION • Nucleic Acid information into Amino Acids • Each Amino Acid has a specific 3 base CODON that codes for it

Basic Process for ALL cells Transcription Translation DNA RNA Protein stored information working copy functional molecule

What is RNA? • RNA: – Ribonucleic Acid – Helps with forming polypeptides from DNA – HOW DOES IT DIFFER FROM DNA? • Uses Ribose /not Deoxyribose • Uses Uracil (U) /not Thymine (T)

What is the triplet code? • Codon: – A set of 3 bases (UAU) (TGC) – Each codon codes for only 1 amino acid – The triplet code is used for every organism