Photosynthesis has a global impact.
Summary
-through photosynthesis, producers convert inorganic carbon dioxide to organic compounds and consumers obtain the organic compounds by eating them, and it may be eaten by another consumer
-cellular respiration by both producers and consumers return carbon dioxide into the atmosphere
- carbon dioxide is the main element
- plants use carbon dioxide to make sugars in photosynthesis
- most organisms give off carbon dioxide as waste in cellular respiration
- carbon dioxide made up 0.03 % of the Earth's atmosphere
-carbon dioxide in the atmosphere traps heat from the sun that would otherwise escape from Earth back into space
- greenhouse effect keeps the average temperature 10 degrees celsius warmer
Vocabulary
carbon cycle- the process by which carbon moves from inorganic to organic compounds and back
greenhouse effect- an important property that keeps the world climate warm enough for living things
Concept Check
1. Give an example of carbon moving from an inorganic compound to an organic compound in the carbon cycle. Give an example of carbon moving from an organic to an inorganic compound.
An example of carbon moving from an inorganic compound to an organic compound in the carbon cycle is a Cape buffalo eating grass. An example of carbon moving from an organic to an inorganic compound is a Cape buffalo being eaten by a lioness.
2. How is carbon dioxide important to Earth's climate?
Carbon dioxide keeps the Earth's climate 10 degrees celsius warmer and it traps heat from the sun.
Wednesday, November 12, 2008
Chapter 8.3
Summary:
- RuBP, a sugar with 5 carbons, is regenerated each time the process occurs
- inputs: carbon dioxide, ATP, NADPH
- the cycle uses the carbon from the carbon dioxide, energy from the ATP, and high-energy electrons and hydrogen ions from the NADPH.
- output: G3P, not yet glucose, but smaller, used by plants to make glucose and other organic molecules it needs
- light reactions take place in the thylakoid membranes
- light reactions convert light energy to the chemical energy of ATP and NADPH
- Calvin cycle, in the stroma, uses ATP and NADPH to convert carbon dioxide to sugar
Concept Check:
1.What are the inputs and outputs of the Calvin cycle?
The inputs are carbon dioxide from the air and the ATP and the NADPH produced by the light reactions. The Calvin cycle's output is a energy-rich sugar molecule called G3P.
2. Which stages of photosynthesis uses each reactant from the overall photosynthesis equation? Which stage generates each product from the overall photosynthesis equation?
The light reaction stage of photosynthesis uses each reactant from the overall photosynthesis equation. The Calvin cycle regenerates the product from the photosynthesis equation.
3. Why is the Calvin cycle called a cycle?
Calvin cycle is a cycle because its starting material, the compound RuBP, regenerates each time the process occurs.
4. What molecule is the direct product of photosynthesis? How is that molecule then used by plant cells?
G3P is the direct product of photosynthesis. It was used to make glucose or other organic molecules.
- RuBP, a sugar with 5 carbons, is regenerated each time the process occurs
- inputs: carbon dioxide, ATP, NADPH
- the cycle uses the carbon from the carbon dioxide, energy from the ATP, and high-energy electrons and hydrogen ions from the NADPH.
- output: G3P, not yet glucose, but smaller, used by plants to make glucose and other organic molecules it needs
- light reactions take place in the thylakoid membranes
- light reactions convert light energy to the chemical energy of ATP and NADPH
- Calvin cycle, in the stroma, uses ATP and NADPH to convert carbon dioxide to sugar
Concept Check:
1.What are the inputs and outputs of the Calvin cycle?
The inputs are carbon dioxide from the air and the ATP and the NADPH produced by the light reactions. The Calvin cycle's output is a energy-rich sugar molecule called G3P.
2. Which stages of photosynthesis uses each reactant from the overall photosynthesis equation? Which stage generates each product from the overall photosynthesis equation?
The light reaction stage of photosynthesis uses each reactant from the overall photosynthesis equation. The Calvin cycle regenerates the product from the photosynthesis equation.
3. Why is the Calvin cycle called a cycle?
Calvin cycle is a cycle because its starting material, the compound RuBP, regenerates each time the process occurs.
4. What molecule is the direct product of photosynthesis? How is that molecule then used by plant cells?
G3P is the direct product of photosynthesis. It was used to make glucose or other organic molecules.
Monday, November 10, 2008
Chapter 8.2
Summary
- The light reactions convert light energy to chemical energy.
- Chloroplasts are chemical factories inside plant cells, that are ran by the sun
- Sunlight is a form of electromagnetic energy, which travels in waves.
- When light shines on a material that contains pigments, three things can happen to the different wavelengths:
*be absorbed
*be transmitted
*be reflected
- Most of the green light passes through the leaf (is transmitted) or bounces back (is reflected)
- Paper chromatography:
1. press a leaf onto a strip of filter paper to deposit a "stain"
2. Seal the paper in a cylinder containing solvents, working under a vented laboratory hood
As solvents move up the paper strip, the pigments dissolve in the solvents and are carried up the strip
Chlorophyll a: absorbs mainly blue-violet and red light and reflects mainly green light
Chrolophyll b: absorbs mainly blue and orange light and reflects yellow-green
Vocabulary
Wavelength: distance between adjacent waves
Electromagnetic spectrum: range of types of electromagnetic energy from gamma waves to radio waves
Pigment: chemical compound that determines a substance's color
Paper Chromatography: laboratory technique used to observe the different pigments in a material
Photosystem: cluster of chlorophyll and other molecules in a thylakoid
Concept Check:
1. Explain why a leaf appears green.
A leaf appears green because the green light is not absorbed.
2. Describe what happens when a molecule of chlorophyll a absorbs light.
Chlorophyll a absorbs mainly blue-violet and red light and reflects mainly on green light, which plays a major role in the light reactions of photosynthesis.
3. Besides oxygen, what two molecules are produced by the light reactions?
Besides oxygen, the two molecules produced by the light reaction are hydrogen ions and NADPH molecules.
4. Where in the chloroplast do the light reactions take place?
The light reactions take place in the inner mitochondrial membrane in respiration and the thylakoid membrane in photosynthesis.
Chapter 8.1
Vocabulary
chloroplast: organelle found in some plant cells and certain unicellular organisms where photosynthesis takes place
chlorophyll: pigment that gives a chloroplast its green color; uses light energy to split water molecules during photosynthesis
stroma: thick fluid contained in the inner membrane of a chloroplast
thylakoid: disk-shaped sac in the stroma of a chloroplast; site of the light reactions of photosynthesis
light reactions: chemical reactions that convert the sun's energy to chemical energy; take place in the membranes of thylakoids in the chloroplast
Calvin cycle: cycle in plants that makes sugar from carbon dioxide, H+ ions, and high-energy electrons carried by NADPH
Concept Check:
1.Draw and label a simple diagram of a chloroplast that includes the following structures: outer and inner membranes, stroma, thylakoids.
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2. What are the reactants for photosynthesis? What are the products?
The reactants for photosynthesis are light energy, carbon dioxide, and water. The products of photosynthesis are glucose and oxygen.
3. Name the two main stages of photosynthesis. How are the two stages related?
The two main stages of photosynthesis are light reactions and the Calvin cycle. The light reactions create ATP for the Calvin cycle to use the energy to make sugar.
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