Autotrophic Nutrition Living Things Making Their Own Food

All Living Things Require Nutrition Nutrition is …. Means of acquiring and using raw materials needed for Life Processes Two Categories of Nutrition: Heterotrophic Autotrophic Heterotrophic Nutrition “Eating Others” Ingesting food (taking-in other living things) Herbivores, Omnivores, Carnivores, Saprophytes Autotrophic Nutrition “Self-Feeding” Make their own food Chemotrophs Phototrophs

Ancient Autotrophs:Chemotrophs Chemotrophs Use Energy produced during Chemical Reactions to change inorganic molecules into Organic Molecules Chemotrophs (Bacteria) are the most ancient life forms on earth; they are extremely important to the recycling of organic matter in food webs

Other Autotrophs Phototrophs absorb Protist Phototrophs absorb Light energy to change inorganic molecules into Organic Nutrients Some Bacteria Green Algae (Protists) Green Plants Algae

Light : part of the Electromagnetic Spectrum we can SEE Made up of particles called photons. Travel in waves, having different lengths The energy a wave has depends on its length The shorter the wave’s length; the greater its energy (indirect) Each wavelength is seen as a different color

Visible Light Spectrum appears white “white light” is really a mixture of different colored waves of electromagnetic energy Longest Shortest ROYGBIV

Chlorophyll: Green Pigment Give green plants and algae their Color Dominant Plant Pigment Absorbs Red and Blue Wavelengths Reflects Green and Yellow Wavelengths Plants appear green because they reflect the green wavelength Chlorophyll (a & b) are the light absorbing pigments of photosynthesis Carotenoids other plant pigments

Pigments and Photosynthesis Absorption Spectrum How do we “read” this kind of graph? Hint: The “peaks” are wavelength colors absorbed by the pigment; the ones used for photosynthesis The Blue-violet colored wavelength Red colored wavelengths

Chloroplasts: "food factory Organelles” Chloroplasts contain the Green Chlorophyll Pigment

Chloroplasts contained in plant/algae cells Photosynthetic algae have chloroplasts

Leaves: Nature’s “Solar Collectors” Leaves are adaptations for photosynthesis Collect maximum amount of Sunlight Cells contain chloroplasts Can regulate water and gases entering and leaving Leaf Cross-section

Photosynthesis “to make with light” Light Energy __CO2 +__ H2O -------------C6H12O6 +__O2 6 6 6 Chlorophyll Carbon Dioxide Water Glucose Oxygen

Guard Cells Regulate Gases Entering and Leaving Leaves Guard cells change stoma openings Guard cells located underside of leaf

Guard Cells Guard cells respond to water available to the plant Stoma opening

Function of Guard Cells CO2 Inner cell wall Inner cell wall Stoma O2 Stoma Open Stoma Closed When water is plentiful stoma Opens to allow Carbon dioxide To enter and Oxygen to leave When conditions are dry & Water is scarce, stoma close To conserve water

Water Movement in Plants Excess Water Leaves through leaf Stoma Water Enters through Roots

Photosynthesis and Chloroplast Light Energy Stroma Grana Chloroplast CO2 + H2O Sugars + O2 (Glucose)

Stages of Photosynthesis (1st) Light-dependent Reactions occur in grana Light O2 Sugars CO2 Chloroplast NADP+ Chloroplast ADP + P (2nd) Light-independent Can happen in light Or Dark Light- Dependent Reactions Calvin Cycle ATP NADPH :

Photosynthesis: Two Stages Light Dependent: Photolysis Occurs in Grana Chlorophyll absorbs light energy; gets really excited Water molecule splits into H and O2; the O2 enters atmosphere, the H is picked-up by NADP NADPH2 ADP + P ATP Light-Independent Calvin Cycle (“carbon fixing”) Occurs in Stroma NADPH2 + CO2 + ATP Glucose C6H12O6

Carbon-Fixation or The Calvin Cycle in “detail” CO2 Enters the Cycle Energy Input ChloropIast 5-Carbon Molecules Regenerated The CO2 entering joins With the Hydrogens to Sugar molecules 6-Carbon Sugar Produced Sugars and other compounds :

Concept Map Photosynthesis Light- dependent reactions Calvin cycle Section 8-3 Photosynthesis includes Light- dependent reactions Calvin cycle takes place in uses use take place in Thylakoid membranes Stroma NADPH ATP Energy from sunlight to produce of to produce ATP NADPH O2 Chloroplasts High-energy sugars Go to Section:

Limiting Factors Affecting Photosynthesis Amount of Light Greater the duration and intensity; greater the rate of photosynthesis Will reach maximum then levels off Temperature Extreme High or Low temperatures destroy the enzymes needed for photosynthesis Amount of Water Photosynthesis requires water; less water will decrease photosynthesis Carbon dioxide Not a limiting factor for land plants Is a limiting factor for aquatic plants Other limiting factors are soil minerals, Magnesium found in chlorophyll molecule