What is the #1 killer in the entire world?
World Hunger Map
PHOTOSYNTHESIS ‘photo’ = light ‘synthesis’=to make
GLOBAL PHOTOSYNTHETIC ACTIVITY
First a little history lesson….. ****gotta give props to these guys!***
Jean Baptiste van Helmont ( ) Doctor Married a rich woman Got to play in chemistry lab a lot, and focused on experiments Over 5 years, he carried out a plant experiment Where does a plant’s mass come from??? Soil? Water?
Joseph Priestley and his experiments… Carried out a very famous experiment using jars, candles, plants and mice…
Jan Ingenhousz Discovered photosynthesis Light is essential for photosynthesis
Photosynthesis is the process by which plants use light energy to make sugar and oxygen gas from carbon dioxide and water AN OVERVIEW OF PHOTOSYNTHESIS Carbon dioxide WaterGlucoseOxygen gas PHOTOSYNTHESIS 6
THE SUN: MAIN SOURCE OF ENERGY FOR LIFE ON EARTH
Remember this Lab Experiment? How did this simulate photosynthesis? What was the baking soda for? What was the sunlight? What did the leaf do?
How do plants get their energy? We get our energy by eating food But plants don´t eat tacos!!
Almost all plants are photosynthetic autotrophs, as are some bacteria and protists – Autotrophs generate their OWN food! – Sunlight energy fuels photosynthesis!!!!! (a) Mosses, ferns, and flowering plants (b) Kelp (c) Euglena (d) Cyanobacteria THE BASICS OF PHOTOSYNTHESIS
Food Chain
WHERE DOES ALL THIS AMAZING CHEMISTRY HAPPEN?
The location and structure of chloroplasts LEAF CROSS SECTION MESOPHYLL CELL LEAF Chloroplast Mesophyll CHLOROPLAST Intermembrane space Outer membrane Inner membrane Thylakoid compartment Thylakoid Stroma Granum StromaGrana
Chloroplasts contain several pigments Chloroplast Pigments – Chlorophyll a – Chlorophyll b – Carotenoids Figure 7.7
WHY ARE PLANTS GREEN? It's not that easy bein' green Having to spend each day the color of the leaves When I think it could be nicer being red or yellow or gold Or something much more colorful like that… Kermit the Frog
Different pigments absorb light differently
Electromagnetic Spectrum and Visible Light Gamma rays X-raysUV Infrared & Microwaves Radio waves Visible light Wavelength (nm)
Sunlight minus absorbed wavelengths or colors equals the apparent color of an object. The feathers of male cardinals are loaded with carotenoid pigments. These pigments absorb some wavelengths of light and reflect others. Reflected light
Why are plants green? Reflected light Transmitted light
WHY ARE PLANTS GREEN? Plant Cells have Green Chloroplasts The thylakoid membrane of the chloroplast is impregnated with photosynthetic pigments (i.e., chlorophylls, carotenoids).
Light Reflected light Absorbed light Transmitted light Chloroplast THE COLOR OF LIGHT SEEN IS THE COLOR NOT ABSORBED
Plants produce O 2 as a waste product!
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2 stages of photosynthesis LIGHT REACTIONS: Produces oxygen Happens in the thylakoid membranes DARK REACTIONS (Calvin Cycle): MAKE GLUCOSE SUGAR Happens in the stroma
Plants’ uses of plant glucose Glucose Used immediately to provide energy source for respiration Energy used to turn sugars, nitrates & other nutrients into amino acids which build up proteins To make cellulose, the main structural material in cell walls Raw material for growth, repair and replacement of damaged parts Energy stored as starch (in leaves, seeds, roots and tubers) To make fats & oils (energy stored in seeds) Energy stored as sucrose (in fruit)
Plants can make their own food! This process is called photosynthesis Raw MaterialsEquipmentProducts Water Where does it come from? Where does it need to go? SunlightGlucose (sugar) Where is this made? Does it stay there all the time? Carbon dioxide Where does it come from? How does the plant take it up? Chloroplasts containing chlorophyll Where are these found? Oxygen How does this escape from the plant?