Presentation on theme: "PHOTOSYNTHESIS. I. Autotrophs and Heterotrophs SUN A.Energy for living things comes from the SUN B.Autotrophs- make their own food Ex: plants, some bacteria,"— Presentation transcript:
I. Autotrophs and Heterotrophs SUN A.Energy for living things comes from the SUN B.Autotrophs- make their own food Ex: plants, some bacteria, protists
Heterotrophs- obtain it from the foods they consume » Ex: animals, some bacteria, protozoans (and even fungi!)
Sooo… food is either MADE through photosynthesis or OBTAINED through consumption
Think about the Location of Photosynthesis…
II. Location of Photosynthesis Which tissues contain chloroplasts?
Other Important Parts Xylem: transports H 2 O Stoma: pore that allows gases to enter and exit
A.Double-membrane structure B.Internal Organization 1. Thylakoids: 1. Thylakoids: III. CHLOROPLAST STRUCTURE a. These have clusters of chlorophyll and other pigments a. These have clusters of chlorophyll and other pigments 2. Stroma: Fluid surrounding thylakoids 2. Stroma: Fluid surrounding thylakoids
IV. Light & Pigments A. Sunlight is “white” but contains mixtures of visible wavelengths PIGMENTS B. Plants gather sun’s energy using light- absorbing molecules called PIGMENTS
V. Plant Pigments Chlorophyll a - Absorbs all colors of light except green - Plays major role in light reactions of photosynthesis Chlorophyll b - Yellow-green Xanthophyll - In carotenoid family - Yellow Carotene - Red & orange pigments MAJOR MINOR
B. Visible energy spans wavelengths of approx nm C. It is part of the electromagnetic spectrum
Plant pigments absorb different wavelengths of energy- which wavelength is the LEAST absorbed? Green is NOT absorbed!
1. Leaves absorb blue-violet & red-orange light very well 2. Green light is REFLECTED which is why plants look green!
VI. PHOTOSYNTHESIS Inputs: Light, carbon dioxide, & water Outputs: sugar and oxygen
VI. Photosynthesis Has Two Parts:
VII. Light Reaction 1.Chlorophyll capture light energy in chloroplast 2.This splits H 2 O into oxygen and hydrogen 3.Oxygen is a "waste product" & escapes to the atmosphere 4.Energy from the reaction is used in the next stage.
B. ATP and NADP are recycled back into the system the system C. Light reaction is charging up the “battery” needed to make “battery” needed to make sugars in Calvin Cycle sugars in Calvin Cycle
IX. Calvin Cycle Does NOT use light at allDoes NOT use light at all Uses energy from Light Cycle to convert CO 2 into glucoseUses energy from Light Cycle to convert CO 2 into glucose
Two Processes Light Reaction Calvin Cycle
Factors Affecting Photosynthesis Shortage of raw materialsShortage of raw materials TemperatureTemperature Light intensityLight intensity