S.HS.3.5.2

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S.HS.3.5.2

• The student understands the Sun
• is the primary source of energy for life through
  the process of photosynthesis

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• What is Photosynthesis? The process of
  photosynthesis is a series of chemical reactions.
  -For living organisms it is the most important
  chemical reaction on our planet

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• What is the equation for the chemical reaction
  for photosynthesis?

chlorophyll
enzymes
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The equation described

• 6 CO2 6 H2O ? C6H12O6 6 O2
• Six molecules of carbon dioxide react with six
  molecules of water to form 1 molecule of glucose
  and six molecules of oxygen.

Chlorophyll enzymes
Low energy
High energy
Low energy
Low energy
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Energy moves through the food chain from life
form to life form.  The first step is
photosynthesis in which the sun's radiant energy,
that pours onto the earth everyday, is turned
into carbohydrate(C6H12O6) molecules.  These
carbohydrates are used by nearly all living
things as fuel for energy, and as building blocks
to biosynthesize larger molecules such as
polysaccharides, protein, nucleic acids and
lipids.
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DESCRIBE PHOTOSYNTHESIS

• It is the process of changing light energy to
  chemical energy stored as sugar
• It occurs in plants and algae
• Plants need light energy, CO2, and H2O
• It takes place in the thylakoids of chloroplasts,
  
• Chlorophyll the green pigment in plants is used
  to absorb wavelengths of light
• 2 stages light dependent and Calvin Cycle or
  light independent

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WHAT HAPPENS DURING PHOTOSYNTHESIS?

• Plants capture light energy and use that energy
  to make glucose
• Sunlight provides the energy needed by
  chlorophyll to change molecules of carbon dioxide
  and water into glucose
• Oxygen is also released in this reaction

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CONTINUED

• Carbon dioxide enters the leaf through pores
  called stomata
• CO2 combines with the stored energy in the
  chloroplasts through chemical reactions to make
  glucose
• The sugar is moved through cells in the leaf to
  the roots, stems and fruits of the plants
• Some of the sugar is used right away by the plant
  for energy some is stored as starch and some is
  built into plant tissue

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WHY IS THIS IMPORTANT TO US?

• We cannot make our own food (glucose, energy), we
  must get our food from plants. Plants are the
  first step in the food chain.

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PATH OF ENERGY

• The flow of energy through life is a one-way
  process. Energy is not recycled. It is
  eventually lost as heat to space.  Energy passes
  through the food chain. The lower on the food
  chain/trophic level, the more energy is
  available.     
• As energy moves up the food chain there is less
  and less of it to go around.  That's the main
  reason there aren't as many big fierce predators
  (lions and tigers and bears-Oh my!) compared to
  the herbivores (mice, rabbits and deer). Not
  enough energy for them! 

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TROPHIC LEVELS!

•  The plants only get a small amount of the solar
  energy that hits the earth.     And....
       The herbivores only get a little bit of the
  energy that hits the plants.     And....     The
  carnivores and decomposers only get a little bit
  of the energy that was eaten by the herbivores.
  Only 10 energy is gained each trophic level

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Why is this important to us?

• Do you breathe?
• The oxygen released during photosynthesis is
  necessary for most living things.

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WHY OXYGEN IS IMPORTANT?

• Oxygen is not just used by our bodies for
  respiration. It's not just in the air. It's the
  most abundant element on earth. And about 65
  percent of the mass of your body is oxygen.

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QUESTIONS

• 1. What is the term for the transfer of energy
  and matter within a food web?
• 2. The first stage of photosynthesis in a
  chloroplast is?
• 3. Which molecule in plant cells first captures
  the radiant energy from sunlight?

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ANSWERS

• 1. A food web showing the tropic levels and where
  energy is transferred
• 2. Light Dependent Reaction
• 3. Chlorophyll pigment

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QUESTIONS

• 4. Photosynthesis uses sunlight to convert water
  and carbon dioxide into?
• 5. A student is collecting gas given off from a
  plant in bright sunlight at a temperature of 27
  C. The gas being collected is?
• 6. If carbon dioxide is removed from a plants
  environment, what would you expect to happen?

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ANSWERS

• 4. Oxygen and Sugars
• 5. Oxygen
• 6. No sugars would be produced

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Prepared are two beakers with identical sprigs of
water plants as shown. One was placed in the
shade and the other by a lamp. Then the distance
of the beakers from the lamp was changed.
Bubbles were counted given off by each plant.
Read the graph.

• 7.

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QUESTIONS

• 7. If the student later tested the bubbles
  collected in the test tube, what would she find
  they are made of? How do you know?
• 8. At what distance from the light source was
  the greatest number of bubbles produced per
  minute?
• 9. What do the students data show?

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ANSWERS

• 7. Oxygen because release oxygen gas during the
  first stage of photosynthesis
• 8. 5 cm-closest to the light source
• 9. The closer to the light source the more oxygen
  bubbles produced.