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The _______ Cycle. Photosynthesis Cellular Respiration. Ch. 8 Photosynthesis. Section 8.1 Goals. 1. Where do plants get the energy they need to produce food? 2. What is the role of ATP in cellular activities?. Autotrophs. Organisms that can make their own food.
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The _______ Cycle Photosynthesis Cellular Respiration
Section 8.1 Goals • 1. Where do plants get the energy they need to produce food? • 2. What is the role of ATP in cellular activities?
Autotrophs • Organisms that can make their own food. auto = self trophe = food
Heterotroph • Obtain energy from the foods they consume. hetero = other trophe = food
Forms of Energy Heat Light Electric Electrochemical Electromagnetic
Chemical Energy and ATP • Adenosine Diphosphate – ADP Made of- • Adenine • 5-carbon sugar ribose • 2 phosphate groups Adenosine Triphosphate – ATP Made of- • Adenine • 5-carbon sugar ribose • 3 phosphate groups
Storing Energy • What does a cell do to store energy it has available? Releasing Energy 2. How is energy stored by the cell released? 3. Explain why only a small amount of ATP is stored? 4. Where do the cells get energy to make ATP?
Storing Energy • What does a cell do to store energy it has available? Answer – The cell adds a phosphate group to ADP. The energy is in the chemical bonds.
Releasing Energy • How is energy stored by the cell released? Answer – Breaking the chemical bonds of the 3rd phosphate releases energy
Explain why only a small amount of ATP is stored? ATP is not good at storing long term energy. 1 Glucose Molecule = 90X energy 1 Molecule of ATP
Using Biochemical Energy • Uses of ATP • Cell movement • Active Transport • Na and K pumps • Organelle movement • Light
Tomorrow • Vocabulary sheet due Thursday • Quarter Exam
The _______ Cycle Photosynthesis Cellular Respiration
Photosynthesis • Plants use the energy from sunlight to convert water and CO2 into high-energy carbohydrates. • Photo = light synthesis = putting together
The Question Question Asked: When a tree grows from a seed to an adult tree, where does the mass come from?
Jan van Helmont (1579 – 1644) • 1643 – Belgian Physician • Tree had gained 75 kg in five years. • Extra mass was from water
Joseph Priestley (1733 – 1804) • 1771 – English Minister • Something in the air kept the candle burning • Plants produced gas that’s important for life and fire.
Jan Ingenhousz (1730 – 1799) • 1779 – Dutch Scientist • Aquatic plants produce oxygen with light • Plants need sunlight to produce oxygen
Photosynthesis Equation Unbalanced Equation- CO2 + H2O C6H12O6 + O2
Light Energy and Pigments • Electromagnetic Spectrum – Arranges electromagnetic energy from short to long wavelengths. Why can these cause cancer?
Pigments • Gives a substance its color. • Light will be absorbed, reflected, or transmitted.
1. Which of the following is an autotroph? • a. mushroom c. monkey • b. dog d. tree
2. Which of the following is NOT an example of a heterotroph? • a. mushroom c. grass • b. Leopard d. human
3. Energy is released from ATP when • a phosphate group is added. • adenine bonds to ribose. • ATP is exposed to sunlight. • d. a phosphate group is removed.
4. Which of the following are used in the overall reactions for photosynthesis? • a. carbon dioxide c. light • b. water d. all of the above
5. Most plants appear green because chlorophyll • a. does not absorb green light. • reflects violet light. • absorbs green light. • d. none of the above
6. Organisms, such as plants, that make their own food are called • a. autotrophs. c. thylakoids. • b. heterotrophs. d. pigments.
7. Jan van Helmont concluded that plants gain most of their mass from • a. water. c. carbon dioxide in the air. • b. the soil. d. oxygen in the air.
The _______ Cycle Photosynthesis Cellular Respiration
Do you think changes to the slow carbon cycle could affect the temperature on Earth? • Do you think humans are affecting the carbon cycle?
8.3 The Reactions of Photosynthesis The requirements of photosynthesis were discovered in the 1800s. Not until the second half of the 1900s that biologists understood the complex reactions during photosynthesis.
The Chloroplast • Captures sunlight and converts CO2 and H20 into food (glucose).
Grana – Stacks of thylakoids Thylakoids – Saclike photosynthetic membranes
Photosystems • 1. Light collecting units of the chloroplast • 2. Cluster made by proteins in the thylakoid membrane organizing chlorophyll
Stroma • Region outside the thylakoid membrane.
Electron Carriers • Sunlight excites electrons in the chlorophyll causing them to gain a great deal of energy. • Carrier Molecule – Compound that can accept a pair of high energy electrons and transfer them along with most of their energy to another molecule – Electron Transport
Location • In the Thylakoids
What goes into the reaction? • 1. Sunlight - Energy • 2. Water • New electrons and H+ ions come from splitting H2O molecules. • 3. NADP+ • 4. ADP
What happens during the reaction? • 1. NADP+ is converted to NADPH • Picks up 2 electrons and H+ • 2. Energy collected turns ADP to ATP. • 3. O2 (oxygen gas) released from splitting of water
What comes out of the reaction? • 1. O2 • 2. ATP • 3. NADPH • Has 2 high energy electrons + 1 H+ ion • Note – ATP and NADPH are not stable
Location • In the stroma
What goes into the reaction? • 1. ATP • 2. NADPH • 2 high energy electrons • 3. 6 CO2 molecules
What happens during the reaction? • Six carbon dioxide molecules enter the cycle from the atmosphere. The carbon dioxide molecules combine with six 5-carbon molecules. The result is twelve 3-carbon molecules. • The twelve 3-carbon molecules are then converted into higher-energy forms. The energy for this conversion comes from ATP and high-energy electrons from NADPH. • Two of the twelve 3-carbon molecules are removed from the cycle. The plant cell uses these molecules to produce sugars, lipids, amino acids, and other compounds needed for plant metabolism and growth. • The remaining ten 3-carbon molecules are converted back into six 5-carbon molecules. These molecules combine with six new carbon dioxide molecules to begin the next cycle.