genetics 2
TRANSCRIPT
GeneticsBy Catherine Bouts
Genes Gene – a segment of DNA molecules
Carry vital hereditary information in organisms
Determine traits of individuals
Hair color, height, blood type etc.
Double Helix Model ‘Spiral Staircase’ appearance
Found in DNA and some RNA
Nucleic Acids connected by nucleotides
Phosphate bonds between nucleotides
Rosalind Franklin July 25, 1920 – April 16, 1958
British scientist who observed DNA
First to examine Double Helix model
Used X-Ray diffraction method
James Watson & Francis Crick Scientists who
‘borrowed’ Rosalind Franklin’s research
Credited for the discovery of
Double Helix
1953 - Proposed the Double Helix Model
Three Structure Types
A-DNA B-DNA Z-DNA
DNA Deoxyribonucleic Acid
Contains the genetic material
Inherited by younger generations
Composed of nucleic acids
DNA Nucleotides Molecules that compose structural units of DNA
Purines & Pyrimidines cannot bond with eachother
Purines Guanine and Adenine
Pyrimidines Cytosine and Thymine
RNA Ribonucleic Acid
Different types with different functions
Composed of different substances Phosphate Ribose sugar Nitrogenous base
RNA Nucleotides Molecules that compose structural
units of RNA
Pyridimines Cytosine and Uracil
Purines Guanine and Adenine
Nucleotide Functions Building blocks of DNA and RNA
Assist in cell metabolism
Chemical energy sources (ATP)
Cellular signaling
Participate in enzyme reactions
Types of RNA mRNA (Messenger RNA)
Carries coding data to protein synthesis
tRNA (Transfer RNA) Transfers amino acids to polypeptide
chains
rRNA (Ribosomal RNA) Decodes mRNA and interacts with
tRNA
Genetic Mutations Changes in the genomic sequence
Causes: radiation, viruses, DNA replication mistakes
Detrimental Mutations CFTR (Cystic Fibrosis)
Beneficial Mutations CCR5 (AIDS)
DNA vs RNA
DNA
Always double stranded
Thymine Longer Helices
RNA
Different types Additional
Oxygen Uracil Less stable
Summary DNA and RNA are composed of nucleic
acids
DNA carries hereditary information
RNA has different types and functions
Double Helix Structure
Franklin, Watson and Crick
Citations Center for Image in Science and Art, “Picture
n 52 – DNA at X-Ray” January 12, 2010, via Flickr , Creative Commons Attribution
Erlon BR, “Watson Crick” May 30, 2008, via Flickr, Creative Commons Attribution
Richard Wheeler, “File:A-DNA, B-DNA and Z-DNA.png” May 16, 2007, via Wikipedia, Creative Commons Attribution
John Haver, “Four Nucleotides” April 28, 2009, via Flickr, Creative Commons Attribution
Winton Snyman, “Nucleotides” December 19, 2006, via Flickr, Creative Commons Attribution