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Explore how living things obtain and use energy through photosynthesis, ATP, and chemical energy processes. Learn about the light-dependent and light-independent reactions involved in converting light energy into sugars, vital for plant energy needs. Discover the importance of ATP in energy transfer and storage in cells.
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Energy and Life • Nearly every activity in modern society depends on Energy…think about it. • Driving a car! • Typing a paper! • Using your IPOD! • Talking on your cell phone! • Living things also require ENERGY!
Where does that Energy come from? • Autotrophs (AKA: Producers) • Use the sunlight as their ENERGY source. Heterotrophs (AKA: Consumers) • Obtain energy from the plants or other organisms that they consume.
Chemical Energy • Candles burn • What does that mean? • Wax molecules store energy in the bonds between the hydrogens and carbons
Electrons move from higher energy levels to lower energy levels. • Heat and light energy are released.
ATP: Adenosine Triphosphate • Adenine • Ribose:5 carbon sugar • 3 phosphate groups
Storing Energy • ADP (adenosine diphosphate) is a compound that looks like ATP except it is lacking a __________ group. • This one difference is the key to the way in which living things store energy. Phosphate
Storing Energy (cont.) • When a cell has energy available, it can store small amounts of it by adding a phosphate group to ADP, producing ATP. • Think of ATP as a fully charged battery and ADP as only a partially charged battery. • Now that we have Energy stored…how do we release it?.... http://www.biologyinmotion.com/atp/index.html
Releasing Energy • Energy that is stored in ATP is released by breaking the chemical bond between the second and third phosphates.
What the energy in ATP can do • Active transport • Protein synthesis • Muscle contraction
What the energy in ATP can do • Synthesis of nucleic acids • Move organelles throughout the cell • Responds to chemical signals of cell • Fireflies!
Question????? • Do you think cells have an abundant amount of ATP? • Answer: Most cells have only a small amount of ATP, enough to last them for a few seconds of activity. • Why? • Answer: ATP is great for transferring Energy, not for storing Energy.
ATP Wrap-UP • Long term storage is done by other molecules, such as glucose, glycogen, starch • ATP can be regenerated by the cell over and over again • ADP + Energy + P → ATP • Required energy comes from food molecules
8-2:Overview of Photosynthesis • Van Helmont’s Experiment • Plants gain mass from water • Priestley • Plants produce oxygen • Jan Ingenhousz • Light is necessary
8-2:Overview of Photosynthesis • Photosynthesis converts light energy into the chemical energy of sugar and other organic compounds. • Light energy drives the reactions • O2- byproduct and is released into atmosphere
Light and Pigments • Pigments: light absorbing molecules • Chlorophyll absorbs blue-violet and red light • When a pigment absorbs light, it absorbs the energy from that light • Energy excites electrons
8-3: The Reactions of Photosynthesis • Where does photosynthesis take place? Chloroplasts!
Parts of the chloroplasts • Thylakoids-Proteins in the thylakoid membrane organize chlorophyll and other pigments into clusters known as photosystems.
Parts of the chloroplasts • Photosystems-light collecting units • Reactions of photosystems in 2 parts: • Light-dependent reactions(take place in thylakoid membrane) • Light-independent reactions(take place in the stroma)
Light-Dependent Reactions • The light-dependent reactions produce oxygen gas and convert ADP and NADP+ into ATP and NADPH. • NADP+ is an electron carrier molecule, which holds two electrons and a Hydrogen Ion which then traps energy and turns it into NADPH which is used to help build glucose • Occur in the thylakoid
Calvin Cycle (light-independent) • The Calvin Cycle uses ATP and NADPH from the light-dependent reactions to produce high-energy sugars. • It takes carbon dioxide from the atmosphere and converts it into high-energy sugars that can be used to meet the plant’s energy needs and to build more complex molecules.
What does all of that mean? • The two sets of photosynthetic reactions work together… • The light-dependent reactions trap the energy of sunlight in chemical form • The light-independent (Calvin cycle) uses that chemical energy to produce stable, high-energy sugars from carbon dioxide and water.
light energy H2O + + + O2 ATP NADPH sunlight Light Reactions H2O • produces ATP • produces NADPH • releases O2 as a waste product Energy Building Reactions NADPH ATP O2
CO2 + + + + ATP NADPH C6H12O6 ADP NADP Calvin Cycle • builds sugars • uses ATP & NADPH • recycles ADP & NADP • back to make more ATP & NADPH CO2 ADP NADP SugarBuilding Reactions NADPH ATP sugars
sun light energy CO2 + H2O + + O2 C6H12O6 glucose H2O ATP energy + O2 + CO2 + H2O C6H12O6 Energy cycle Photosynthesis plants CO2 O2 animals, plants Cellular Respiration ATP
Factors Affecting Photosynthesis • Shortage of water can slow down or stop photosynthesis • Plants have adaptations to reduce water loss: waxy coating on plants in dry areas. • Temperature • Plants have enzymes that work best from 32-95 degrees F. Temperatures above or below can damage these enzymes which can slow down or stop photosynthesis.
Factors Affecting Photosynthesis • Intensity of light • Increasing light intensity increases the rate of photosynthesis. (It will reach a max level)
Chromatography Lab • Purpose: To discover all the pigments in both spinach leaves and M&M dyes. (Test at least three M&M colors) Also Test, coffee filter chromatography vs. actual chromatography paper • Procedure: 1. Grind down spinach leaves with a mortar and pestle. (Melt M&M’s in your hand). • 2. Pour about ¼ inch of alcohol into your beaker. Draw a small line on the bottom of your Filter paper, above the alcohol level. • 3. Place a dot of the dye in the middle of your line, then place paper wrapped around pencil into beaker so bottom is touching the alcohol. • 4. Place a line wherever pigment colors show. Measure this distance, as well as the distance the alcohol traveled up the paper. • 5. Measure the Rf, retardation factor for each pigment. Rf = distance pigment traveled from baseline/ distance alcohol traveled.