intro to genetics: dna structure & function
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Intro to Genetics: DNA Structure & Function. Genetics: the study of heredity What determines an organism’s traits (characteristics)? How are traits passed on from one cell to another, and from parents to offspring? DNA: the molecule that carries genetic information - PowerPoint PPT PresentationTRANSCRIPT
Intro to Genetics:DNA Structure & Function Genetics: the study of heredity
What determines an organism’s traits (characteristics)?
How are traits passed on from one cell to another, and from parents to offspring?
DNA: the molecule that carries genetic information
DNA has two important functions: Carry instructions for making proteins that
determine your traits Replicate – make exact copies of itself so it can
be passed on DNA is found in all cells (in the nucleus in
eukaryotic cells)
DNA
ChromosomesVery long, coiled/bunched up strands of DNA that contain many genes
Gene: Instructions for making a protein that determines a traitAnother Gene:
instructions for making a different protein that determines a different trait
Nucleotide Base PairsBuilding blocks of DNA
Genetic Info in Cells
DNA Structure
Objectives for Class:Describe the structure of DNA.
DNA Structure DNA is made out of
Nucleotides Nucleotides have 3 parts:
Deoxyribose Sugar Phosphate Nitrogenous Base (A, T, C, or
G) DNA molecule = double helix
of nucleotides Sides: alternating phosphates
& sugars Middle/ “Rungs” of ladder:
Pairs of Nitrogenous Basesconnected by Hydrogen bonds
Objectives for Class:Describe the structure of DNA.
Base PairingA ---- THydrogen bonds
connect themG ---- C
Objectives for Class:Describe the structure of DNA.
DNA Structure: Images
Objectives for Class:• Describe the structure of DNA.
DNA Replication: Overview DNA can make an
exact copy of itself!
Occurs every time a cell needs to reproduce
What is the first thing that would need to happen to replicate this DNA?
Objectives for Class:Describe the structure of DNA.
Steps of DNA Replication1. Double helix splits
(unwinds and unzips) Hydrogen Bonds break Separates into 2 single
strands2. New nucleotides match
up with each side DNA Polymerase is the
enzyme that does this Matches according to base-
pairing rules3. Two new strands twist upResult: Two Double Helices
Each half old, half new.
Objectives for Class:• List the steps of DNA replication
DNA Replication: Summary
Bio 9B: Friday, 2/17/12Title: DNA Review
Homework: Optional - Finish Parts 2 and/or 3 of the DNA Review PacketSilent Do Now: (in notebook w/ title & date)
1. Write the complementary base sequence to this single strand of DNA
2. Which of the pictures below best illustrates DNA replication? Why?
G A A C G T
A. B. C.
Bonus: Who is the perfect Valentine for a gentleman named CTCT?