CHAPTER 7 TEST ESSAYS

#1 What is chromatography?

• Separation of pigments In a solvent according to their densities

• For plant pigments, we use acetone/ethanol solution

• Set-up: taper chromatography paper, mark starting point, and put just the tip in the solvent

#1 Chromatography

Different months will show different chromatography strips of pigments:SEPT. –mostly chlorophyll LATE OCT.- chlorophyll is gone

Pigments in Leaves

• carotene-yellow orange

• chlorophyll a-bright green

• Xanthophylls-yellow

• chlorophyll b-khaki green

Why do leaves change color?

• Chlorophyll breaks down and exposes the other colors that were there all along, but were masked by the green chlorophyll.

• As fall comes there

are shorter days of sunlight

• Less photosynthesis means less food for plants.

#2 Greenhouse Effect• = the capacity of certain gases in the

atmosphere to trap heat emitted from the Earth’s surface, thereby insulating and warming the Earth.

• The Greenhouse Effect (nice little link)

#2

• Man-made Greenhouse

• UV radiation can enter the glass

• Glass traps

infrared radiation and it heats up

• Earth’s Greenhouse

• UV radiation can enter through clouds

• Infrared radiation get trapped and heats up the earth

Clouds trap the infrared rays

If no clouds, the infrared rays go into space.

Man-Made Greenhouse

UV rays can enter

Infrared rays get trapped inside the greenhouse and warm it

Greenhouse Gases

• Gases that absorb heat:

• carbon dioxide

• Water vapor

• Methane

• And cause global warming

#3

• Global Warming, increase in the average temperature of the atmosphere, oceans, and landmasses of Earth.

Problems with Global Warming

• Melt polar ice caps and glaciers as well as warm the oceans,

• Flooding some coastal regions and even entire islands.

• Some regions in warmer climates will receive more rainfall than before, but soils will dry out faster between storms.

More Problems with Global Warming

• This soil desiccation may damage food crops, disrupting food supplies in some parts of the world.

• Plant and animal species will shift their ranges toward the poles or to higher elevations seeking cooler temperatures, and species that cannot do so may become extinct.

More Problems

– Spreading disease – Earlier spring arrival – Plant and animal range shifts and population

changes – Coral reef bleaching – Downpours, heavy snowfalls, and flooding – Droughts and fires

Why Global Warming Could be Good

• Increased photosynthesis for agriculture and forests on a short term basis (some gardeners pump CO2 in their greenhouses)

• Some cold climates (like Canada) could have a longer growing season if warmer

Causes of Global Warming

• Carbon Dioxide from factories, cars (burning of fossil fuels)

• Nitrous oxides from airplanes’ emissions

USA: Global Warming Hog

#4

• Formula: Ozone (O3)

• GOOD FOR: ozone in the upper atmosphere protects living organisms by preventing damaging ultraviolet light from reaching the Earth's surface

• O2 - two oxygen atoms - ordinary common or garden oxygen

• O3  - three oxygen atoms - Ozone

Ozone hole over Antarctica

Ozone is thinnest over Antarctica

What are CFC’s?

• The compounds that contain only carbon, chlorine, and fluorine are called Chlorofluorocarbons, usually abbreviated as CFCs.

• Banned (by Montreal Protocol) but were usually in aerosols like spray deodorants and making of Styrofoam

Why are CFC’s bad?

• Chlorine bonds with the oxygen and breaks down O3 to just O2

(non-protective layer)

• So, the earth would be left without the ozone to protect it from harmful radiation

Negative effects of ozone depletion

• Increased skin cancer and illness due to damaging the immune system

• Too much UV radiation harming aquatic young

• Especially harms phytoplankton (microscopic plants) in the oceans which feed a lot of other organisms

• The Ozone Hole-Ozone Hole Consequences (nice link)

Nice Links

• EEK! - Hole in the Ozone Layer?

• Antarctic Ozone Hole