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Cell Energy. When do you use energy? List all of the ways you have used energy today. Without the ability to obtain and use energy, life would not exist. Forms of Energy. Energy comes in many forms: Light Heat Electricity . . . Energy can also be stored in the bonds of chemical compounds.
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When do you use energy?List all of the ways you have used energy today.
Without the ability to obtain and use energy, life would not exist.
Forms of Energy • Energy comes in many forms: • Light • Heat • Electricity • . . . Energy can also be stored in the bonds of chemical compounds.
2 types of energy in living things • Autotrophs- organisms that get their energy directly from the sun. • Examples: • Heterotroph- Organisms that eat food to obtain their energy. • Examples: • ALL energy begins with the sun! • How does a heterotroph get energy from the sun?
Chemical Energy • The main compound cells use to store and release energy = ATP
1. ATP = adenosine triphosphate ATP is a high energy compound 2. ADP... adenosine diphosphate (1-less phosphate group and less stored energy)
Important Scientists Van Helmont- - Wondered if plants grew by taking mass out of the soil? - Measured the soil, planted a seed and watered the plant until it grew. - After 5 years, plants weighed 75 kg and the soil was unchanged! Concluded- water (hydrate) that made the plant grow!
Another Scientist • Priestley- • Light a candle, put a glass jar over it • Candle goes out immediately! • Second time lit a candle with a sprig of fresh mint • Candle burned for much longer than without mint. • Why? • Mint produces oxygen- necessary to burn!
Last Scientist • Ingenhousz- • Added to Priestly’s experiment • Concluded that plant must be exposed to light in order for “Priestly” effect to work. • No light, no photosynthesis!
The two cell energy processes we will discuss = • Photosynthesis • Cellular Respiration
TO DO In your notebook write the following equations. 1. Show ATP breaking down to ADP 2. Show ADP capturing energy to make ATP
TO DO #2 Write the following equations in your notebook. (should use a new page) 1. Write the chemical equation for photosynthesis 2. Write the photosynthesis equation out in words. 3. Write the photosynthesis equation out in pictures. Be sure to add color!
Photosynthesis CHAPTER 8 PAGE 201
Photosynthesis Definition: The conversion of light energy into chemical energy stored in organic compounds Who can do this? …Plants and Algae
Chemical Equation In other words, remember this: carbon dioxide + water + light energy = glucose + oxygen As a chemical reaction it's like so: 6CO2 +6H2O = C6H12O6 + 6O2
Photosynthesis Equation • Learn the song! It will help! • On a separate sheet of paper (next page of notes) 1. Write the chemical equation for photosynthesis 2. Write the equation for photosynthesis out in words 3. Write out the equation for photosynthesis in pictures! Use the colored pencils!
Where does it happen? • Within the CHLOROPLAST of a plant cell Draw & label in notes!
Photosynthesis begins with the absorption of light by pigments in the thylakoids • Main pigments in plants = chlorophyll. It absorbs all colors of light, and reflects back green. PIGMENTS
Light and Pigments • In addition to water and carbon dioxide, photosynthesis requires light and chlorophyll. • Chlorophyll is found in chloroplast! (green) • Plants gather the sun’s light in pigments. (light absorbing molecules) • Since light is a form of energy, anything that absorbs light is also absorbing energy!
Chlorophyll Absorption • Complete handout activity on chlorophyll absorption!
DO NOW: Pigments • 1. Write the balanced chemical equation for photosynthesis. • 2. What pigment does the chloroplast contain? • 3. What does the pigment do in a plant?
Photosynthesis Lab • 1. Use your textbook, page 206 for setup instructions. • 2. Once your lab group has your lab set up please return to your seats. Be sure to leave your lab area clean! • 3. After we return to your lab answer questions 1-3.
How does it happen???? 2 Major Groups of Reactions A. Light Dependent B. Calvin Cycle
Photosynthetic Processes • Light Reactions- Trap the energy from sunlight. • Calvin Cycle- use energy from light reactions to produce sugars. Carbon Dioxide and Water are needed with light, sugar is produced and oxygen given off! (remember equation)
A. Light Reactions • Reaction occurs in the membrane of the thylakoid Chloroplast Circle on the diagram you drew.
A. Light Reactions-con’t 2. Light excites e- in chlorophyll pigments (e- go from low energy to high energy) 3. e- travel to other molecules in membrane, losing energy along the way
This process is called THE ELECTRON TRANSPORT CHAIN (ETC)
Final Step:4. e- combine to make… ADP + phosphate + e-ATPWhen the bond in ATP is broken, energy is released!
Summary of Light Reactions... Needed: Light energy & H2O Made: ATP, H+ Waste: Oxygen
TO DO: Photosynthesis • What is the complete chemical equation for photosynthesis? • Where does photosynthesis take place • What organelle? • What part of the organelle? • Light Reactions- • Dark Reactions- • What is formed when electrons share their energy with other electrons?
B. Calvin Cycle (a.k.a. Dark Reaction) produces glucose • Occurs in stroma of chloroplast (circle on your diagram) • Uses ATP and H from light rxn. • ATP + H + CO2(from air) = glucose (carb) Photosynthesis Animation!
C h l o r o p l a s t Solution- STROMA THYLAKOID
The exchange of gases between the leaf and the atmosphere occurs through the STOMATA
Summary Light Reaction *Makes ATP from ADP Calvin Cycle *Makes glucose
Factors Affecting Photosynthesis Water amounts- Shortage of water can slow down or stop the rate of photosynthesis. Temperature- Photosynthesis likes to occur between 0-35˚ Celsius. Intensity of Light- not enough light, no photosynthesis. Every plant needs a different amount of light.
