UNIT 5: PHOTOSYNTHESIS

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UNIT 5 PHOTOSYNTHESIS CELLULAR RESPIRATION
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ENERGY AND LIFE

• Living things depend on energy
• Sun is source of most energy
• 2 types of organisms,
• AUTOTROPHS make their own food (Ex plants,
  bacteria, protists)
• HETEROTROPHS get energy from the foods they
  consume (animals, fungi)

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KEY CONCEPT PHOTOSYNTHESISThe overall process
of photosynthesis produces sugars that store
chemical energy.
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Photosynthetic organisms are producers.

• Plants use photosynthesis and are
  producers/(autotrophs.)
• Photosynthesis captures energy from sunlight to
  make sugars.

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Research On Photosynthesis

• VAN HELMONT- determined in the 1600s that plants
  grew because of water.
• PRIESTLEY- found that plants release oxygen.
• JAN INGENHOUSZ- found aquatic plants produce
  oxygen bubbles in the light, therefore plants
  need sunlight to produce oxygen

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AN OVERVIEW OF PHOTOSYNTHESIS

• Plants use the energy of sunlight to
• convert water carbon dioxide into high energy
  carbohydrates (sugar)
• oxygen is a waste product.
• light
• 6H2O 6CO2 ? C6H12O6 6O2
• Reactants Products

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What Else Does The Photosynthesizer Need?

• Chlorophyll- a chemical pigment that traps the
  energy of the sun and converts it to chemical
  energy

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Capturing Light Energy

• White light ROY G BIV
• Chlorophyll captures (absorbs) energy at the ends
  of the spectrum (red/orange blue/violet)
• What you see is the wavelengths that are
  reflected. (green)

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Where Photosynthesis Occurs

• In the chloroplast

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Where Photosynthesis Occurs

• Chlorophyll is a molecule that absorbs light
  energy.

• In plants, chlorophyll is found in
  organelles called chloroplasts.

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• Photosynthesis is Many Reactions
• The equation for the overall process is
• 6CO2 6H2O ?????? C6H12O6 6O2

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FACTORS THAT AFFECT PHOTOSYNTHESIS

• Amount of Water
• Amount of CO2
• Temperature
• Intensity of Light
• Wavelength of light

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Cellular Respiration
KEY CONCEPT The overall process of cellular
respiration converts sugar into ATP (energy)
using oxygen.
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CHEMICAL ENERGY AND ATP

• All living things use chemical energy
• A chemical compound that cells use to store and
  release energy is ATP (ADENOSINE TRIPHOSPHATE).
• ATP is like a fully charged battery ready to
  power the machinery of a cell.
• ATP powers many cellular activities Ex
• active transport across cell membranes,
• protein synthesis
• muscle contraction.

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Cellular Respiration

• Cellular respiration makes ATP (energy) by
  breaking down sugars.
• Cellular respiration is aerobic, or requires
  oxygen.
• Cell respiration takes place in mitochondria.

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Cellular Respiration

• The electron transport chain produces a large
  amount of ATP (energy.)

• oxygen enters process
• PRODUCT
• ATP

• WASTE PRODUCTS
• Water
• Carbon dioxide

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Cellular Respiration

• The equation for the overall process is
• C6H12O6 6O2 ?????? 6CO2 6H2O

• The reactants in photosynthesis are the same as
  the products of cellular respiration.

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ATP synthase (dont copy)

• Is an enzyme (-ase ending is a hint)

• Is a membrane protein.
• It is a protein pump that allows H ions to pass
  thru the cell membrane
• This is necessary for the formation of ATP

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Quick Review of Organic Molecules in Living Things

• Carbohydrates (sugars, starches, etc.)
• Proteins
• Lipids (mainly fats)
• Nucleic acids (ATP, NADP, RNA, DNA)

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Cellular Respiration

• Cells do not burn glucose, instead they slowly
  release energy from glucose
• They do this in many small steps-
• WHY?

If all the energy was released once, it would be
too much for the cell and it would be destroyed!
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ANAEROBIC RESPIRATION

• When O2 is not present, a process called
  FERMENTATION takes place.
• FERMENTATION releases a small amount of ATP
  (energy) from sugar.

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2 Types of Fermentation

• ALCOHOLIC FERMENTATION
• produces carbon dioxide and alcohol.
• This type of fermentation causes bread dough to
  rise.
• .

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2 Types of Fermentation, cont.

• 2. LACTIC ACID FERMENTATION
• is produced in your muscles during rapid exercise
  when the body cant get enough oxygen to the
  tissues.
• With rapid exercise your muscles run out of
  oxygen. Your muscle cells rapidly begin to
  produce ATP by LACTIC ACID FERMENTATION

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Fermentation

• Also occurs in the CYTOPLASM