What is a gene and what does that

What is a gene, and what does that have to do with evolution? Discussions start this week.

Two ways to think about the world: Reductionism atoms molecules organelles cells tissues organs systems organisms environment

Two ways to think about the world: Reductionism atoms molecules organelles cells tissues organs systems organisms holismenvironment

Two Approaches to Biology holism reductionism

To understand complex systems, we must understand simple systems and visa/versa holism reductionism

Possible Topics for this Semester • Global Warming • Overpopulation • Energy Production/ Use • Pandemics • Genetically Modified Organisms • Water Pollution • Animal Rights • Air Pollution • Acid Rain • Deforestation • Wilderness • Endangered Species • Ozone Hole

Fig 54. 1 Ecological Interconnections

CO 2 levels in Hawaii and average global temp. Fig 54. 15

Effects of global warming are already visible 1914 2004 http: //www. nationmaster. c om/graph/env_co 2_emienvironment-co 2 emissions

Polar bears need ice to hunt

Arctic Sea Ice 1979 2003

Without sea ice, polar bears will go extinct

Wangari Maathai - Resources and Conflict http: //youtube. com/watch? v=d. A 0 q. Glnc-30

An Animal Cell Videos: We did not see these in class, but they will give you an idea about what cells can do. . . http: //www. microscopyu. com/moviegallery/livecellimaging/a 549/index. html http: //plantsinmotion. bio. indiana. edu/plantmotion/starthere. html Fig 7. 6

Fig 15. 3 Information flow in cells Protein

Genes code for proteins… Proteins are the “doers” of the cell. They act as: • Enzymes • Structural Support • Transporters • Signals

Chains of DNA can store information: Fig 4. 6, . 7 Each chain of DNA is made of individual units = nucleotides

Fig 15. 3 Information flow in cells Protein

The basic structure of amino acids Fig 3. 2

Fig 3. 3 the 20 Amino Acids

Amino acids connect together to make proteins. Tbl 3. 3

Proteins are the “doers” of the cell. They act as: • Enzymes • Structural Support • Transporters • Signals Fig 3. 8 Proteins are a string of amino acids

The relationship between DNA and genes a gene - DNA used to produce RNA or protein promoter coding region terminator non-gene DNA

Only a small percent of DNA codes for proteins

DNA Composition: In humans: • Each cell contains ~6 billion nucleotides of DNA. • This DNA is ~2 meters long and 2 nm wide. • ~98% does not directly code for amino acids • In a single human cell only about 3 -5% of genes are expressed at a time.

Length of human DNA in each cell The length of DNA in each of your cells is longer than you are tall. Width of DNA Power of ten: http: //www. youtube. com/watch? v=A 2 cmlhfdxu. Y

DNA Composition: In humans: • Each cell contains ~6 billion base pairs of DNA. • This DNA is ~2 meters long and 2 nm wide. • ~1. 5% directly codes for amino acids • ~25% is genes • In a single human cell only about 5 -10% of genes are expressed at a time.

The relationship between DNA and genes a gene - DNA used to produce RNA or protein promoter coding region terminator non-gene DNA