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