Warm-Up
• Where is DNA found?
• What is DNA?
• What do you know about the structure of DNA?
Chapter 11DNA & Genes
Section 11.1 DNA: The Genetic Code
DNA (Deoxyribonucleic Acid)
• The main substance in chromosomes.
• It carries genetic information (determines traits)
• Replicates itself
• Makes RNA (Ribonucleic Acid)
• Makes proteins
DNA (Deoxyribonucleic Acid)
• Made up of Nucleotides – sugar, phosphate, and nitrogen base
DNA
• Double Strand - aka Double Helix
4 Nitrogen Bases• Adenine• Guanine• Thymine• Cytosine
Nitrogen Bases
• Adenine always combines with Thymine
• Guanine always combines with Cytosine
DNA• Sugar = Deoxyribose• The sugar and the phosphate group of the chain
and the nitrogen bases stick out like teeth on a zipper
DNA
• The stands of the molecule are made of alternating bonds of sugar and phosphate.
• The bases are connected to the sugar and held together by a weak hydrogen bond.
History of DNA
• James Watson & Francis Crick formulated the model for DNA.
• Rosalind Franklin had taken many x-rays/pictures.
DNA Replication
• DNA copied during Interphase in the chromosomes
• 1. Hydrogen bonds break at the nitrogen base pairs
• 2. Strands unzip
• 3. Free floating nucleotides bond to the single strands
• 4. Product is 2 molecules of DNA
• DNA proving innocence
• http://youtu.be/PdUpbJsjnkc
Top Related