Photosynthesis How organisms make energy
Life on Earth • During the early days, Earth had extreme temperatures and no oceans – not an environment living things can survive in • Eventually a layer of oxygen formed the ozone protecting the Earth from harmful UV radiation • Water started collecting to form the oceans
Greenhouse effect • The ozone trapped in carbon dioxide and other gases • At the same time oceans absorbed some of the carbon dioxide • This lead to the greenhouse effect which is what gives our planet a temperature where living things can exist (not be destroyed by solar radiation or extreme cold) • greenhouse effect and global warming
Rise in temperatures • The greenhouse effect is necessary for life to exist, but the increase in carbon dioxide from fossil fuels could potentially lead to serious problems. • Fluctuations in Earth’s temperature happen naturally, but scientists are concerned about the effect humans are having.
First half of the Carbon AND Oxygen cycle • Carbon dioxide is taken out of our atmosphere 2 ways: – Absorbed by the ocean (and used in photosynthesis of ocean “plants”) – Absorbed by plants on land to be used in photosynthesis
Producers • Take what they need to live : matter and energy – from nonliving things (CO2 + H2O) • Use solar energy to make usable chemical energy needed for life: Carbohydrates. • Use matter – like nitrogen and water from the soil – to use in chemical reactions to make building blocks it needs.
All Producers have Chloroplasts •Organelle (cell part) where photosynthesis takes place •Contain chlorophyll: pigments that give chloroplasts green color
Pigments
• Sunlight is a form of electromagnetic energy • Travels in waves • Wavelength- distance between two waves • Pigments- chemical compounds that affect the color of a substance • Pigments either absorb, transmit, or reflect wavelengths of light • Pigments in chloroplasts (chlorophylls) absorb blue-violet and redorange light, green light bounces back or passes through
Two Step Process • Photosynthesis occurs in two steps: – Light Dependent Reaction • Needs sunlight – Light Independent Reaction • Calvin Cycle • Does not need sunlight
Photosynthesis