What is DNA? Instructions for making proteins ‘Blueprint’ for who we are Where is it found? Found in the nucleus What does ‘DNA’ stand for? Deoxyribonucleic Acid

The Structure of DNA Double helix Structure of DNA: Twisted Ladder

Who Discovered DNA’s Structure? SCANDAL! Read all about it! Rosalind Franklin, James Watson, Francis Crick, & Maurice Wilkins discovered the shape (double helix) of DNA is 1953.

DNA is a polymer of Nucleotides. What are the 3 parts of a nucleotide? THINK! DNA is a polymer of Nucleotides. What are the 3 parts of a nucleotide?

Nucleotides DNA Subunit 3 components a sugar a phosphate group a nitrogen base

Nitrogen Bases 4 Types: Adenine Thymine Guanine Cytosine REMEMBER: At The Golf Course

Complementary Base Pairs Nitrogen bases always pair with the same partner Hydrogen bonds hold the bases together. A--T (At--The) G--C (Golf--Course)

THINK! What would the complementary strand be? A-T-C-C-G-T-T-T-A-C-A-G-G-A T-A-G-G-C-A-A-A-T-G-T-C-C-T

DNA Review

DNA is the instructions for making what?

Protein

What type of biomolecule is DNA?

Nucleic Acid

What type of sugar is in DNA?

Deoxyribose or pentose

Draw and name the shape of dna

Double Helix

Who took credit for discovering dna?

Watson and Crick

Who actually discovered dna?

Rosalind Franklin

What is a polymer?

A long chain of repeating units (subunits)

What is the subunit of DNA?

Nucleotide

Sugar, phosphate and ___________ make up a nucleotide.

Nitrogen Base

Adenine, ________, cytosine, and __________ are the 4 nitrogen bases of dna

Thymine and guanine

Thymine pairs with ___________

Guanine pairs with __________

Write the complimentary stand: C – G – T – A

G - C – A – T

Write the complimentary strand: g – g – t – a – t – a

Write the complimentary strand: a – a – t – g – c

Write the complimentary strand: c – t – a – t – g

Nucleotides join to form long chain (polymer) Sides of the ladder: How DNA Strands Form Nucleotides join to form long chain (polymer) Sides of the ladder: Sugar + Phosphate Rungs of ladder: Nitrogen bases bond together

How is DNA Organized? Histone proteins act like spools that wind up DNA to keep it organized.

During Interphase… How does DNA exist? Unwound! (Chromatin)

Why Chromatin? What happens during Interphase? DNA Replicates! DNA is uncoiled so that enzymes can unzip it. When it is unzipped, DNA can be duplicated.

DNA Replication Process by which DNA is copied Occurs before mitosis and meiosis (during interphase!)

How DNA Duplication Occurs Step 1: The Helicase enzyme unzips the DNA strand T A G C HELICASE

Step 2: The DNA Polymerase enzyme attaches free floating nucleotides to the exposed nitrogen bases

Result: 2 Complete Strands! G C

DNA Polymerase Replication Fork Original Strand Helicase New Strand

Semiconservative Replication: one of the original strands is present in each new strand of DNA.

The Central Dogma DNA RNA Proteins