Photosynthesis versus Cellular Respiration

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Photosynthesis versus Cellular Respiration
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Photosynthesisvideo Where do plants get their
mass from? https//www.youtube.com/watch?v2KZb2_v
cNTg

• Diagrams and much of the wording here is taken
  directly from http//www.hobart.k12.in.us/jkousen/
  Biology/phobig.html

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What is photosynthesis?

• Photosynthesis is a chemical reaction in which
  light energy is converted to chemical energy in
  glucose.  It is the means by which the energy in
  sunlight becomes usable to living things.  Living
  things can eat glucose, we can't eat sunlight.

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Why is photosynthesis important?

• Two big reasons.  One product of photosynthesis
  is glucose (sugar), which provides the basis for
  most food chains.  The second product of
  photosynthesis is oxygen which comes in handy if
  you happen to be an aerobic organism that
  requires oxygen for survival.

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Class handout plant notes, Galoob, Biology
leaf diagram and photosynthesis cartoon drawing
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1.
http//www.ftexploring.com/me/photosyn1.html
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Leaf structure

• The top and bottom layers are referred to as an
  epidermis. They are protective layers.
• The cuticle is a waxy surface that protects the
  leaf and prevents excess water loss.
• The mesophyll is the middle layer made of
• Palisade tightly packed oval cells
• Spongy layer circular cells that are spread out
  allowing gases to circulate within the leaf.

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Plant Veins transport materials between the roots
and leaves.

•  

• Xylem tubes to transport water and minerals from
  the roots up through the stem and into the
  leaves.
• Phloem tubes to transport sugars made during
  photosynthesis down through the plant.

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Stomates and Guard Cells holes in the underside
of leaves where gases go in and out.

• Plants respond to changes in temperature and
  humidity by opening and closing their stomata.
• Stomata small openings on the lower epidermis
• Guard cells surround the stomates and swell and
  shrink to open and close the stomates.

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Chloroplasts

• The black dots in the cells of the mesophyll
  represent chloroplasts. The cells of the
  palisades have the most chloroplasts, therefore
  the greatest amount of photosynthesis happens
  there.

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Leaf structure quiz

• Questions 1-7 refer to the diagram to the left.
• Write the number and name of the principal area
  of photosynthesis.
• Write the number and name of the structure that
  regulates the opening and closing of stomates.
• Which number indicates where oxygen exits the
  leaf?
• Which numbers indicate the vascular tissue, which
  transport materials to and from the leaf?
• What are the names of the vascular tissues?
• Write the number and function of the cuticle.
• What do the black dots represent?

Questions 9-10 DO NOT directly refer to the
diagram 9. a. What do plants require for
photosynthesis? b. Where do they get these
things from? c. What plant organs are involved
in obtaining them? 10. a. What do plants produce
as a result of photosynthesis? b. Where does the
reaction take place? c. What happens to the
products?  
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Leaf structure quiz

• Write the number and name of the principal area
  of photosynthesis.
• 3 or 4 Palisades, ½ pt
• spongy layer, or mesophyll ½ pt
• Write the number and name of the structure that
  regulates the opening and closing of stomates.
• 8 ½ pt
• Guard cells ½ pt
• Which number indicates where oxygen exits the
  leaf? 9 ½ pt
• Which numbers indicate the vascular tissue, which
  transport materials to and from the leaf? 5 and 6
  ½ pt
• What are the names of the vascular tissues? Xylem
  and phloem ½ pt each
• Write the number and function of the cuticle.
• 1 ½ pt
• protection ½ pt
• What do the black dotes represent? Chloroplasts ½
  pt

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9. a. What do plants require for photosynthesis?
Need all 3 1 pt 1. Sunlight, 2. Carbon
dioxide/CO2, 3. Water b. Where do they get these
things from? ½ pt 1. The air, 2. and soil c.
What plant organs are involved in obtaining them?
1. leaves or stomates ( get CO2) ½ pt 2. roots
(get water) ½ pt 10. a. What do plants produce
as a result of photosynthesis? 1. Glucose or
sugar or carbohydrate, ¼ pt 2. Oxygen ¼ pt b.
Where does the reaction take place? Leaves or
chloroplasts, or mesophyll ½ pt c. What happens
to the products? 1. Glucose becomes part of
plant used by plants or animals for energy ½ pt
2. Oxygen becomes part of air ½ pt  
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• Learning is not a spectator sport get off the
  bench and get in the game!

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WHY are plants green? Do they contain other
pigments?

• http//mw.concord.org/modeler/
• Harvesting light activity
• Chlorophyll doesnt absorb light in the green
  region of the spectrum.
• Molecular workbench activity harvesting light
  for photosynthesis http//www.concord.org/project
  s/samcurriculum (our projects, SAM,
  Activities, harvesting light)
• 2 minute video why do leaves change color
  http//www.youtube.com/watch?vIPvbl1mu7kM

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Class handout Photosynthesis background
knowledge
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Photosynthesis Background Knowledge questions

• Question What is the complete name of the
  molecule that is made and used by almost every
  cell to fuel biological processes?
• Adenosine triphosphate
• Abbreviation ATP

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Question What part of the molecule contains weak
bondshigh chemical energy?
The phosphate groups are added or lostATP (tri 3
phosphate) to ADP (di 2 phosphate)
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What type of chemicals are in our food that
eventually are used to create ATP?

• Carbohydrates like glucose

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What did each of the following scientists
discover about plant growth?

• Van Helmont most of the mass that a plant gains
  comes from water not soil.
• Priestly plants release oxygen
• Ingenhousz light is necessary for a plant to
  produce oxygen

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Describe the process of photosynthesis including
reactants and products.

• Light energy 6CO2 6H2O C6H12O6 6O2
• Purpose Energy Storage in bonds of glucose sugar
• Reactants 6CO2 6H2O
• Products C6H12O6 6O2

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Why are light and chlorophyll needed for
photosynthesis?

• They allow a plant to take water and CO2 to make
  high energy sugar

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Why are plants green?

• Chlorophyll doesnt absorb light in the green
  region of the spectrum.
• Molecular workbench activity harvesting light
  for photosynthesis http//www.concord.org/project
  s/samcurriculum (our projects, SAM,
  Activities, harvesting light)
• 2 minute video why do leaves change color
  http//www.youtube.com/watch?vIPvbl1mu7kM

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Using the graph below what colors of light does
chlorophyll a absorb? Chlorophyll B?

• Chlorophyll a violet and red
• Chlorophyll b blue and red.

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Using the graph below, how well would a plant
grow under pure yellow light? Explain

• The plant would not grow well because neither
  chlorophyll a nor b absorbs much light in the
  yellow region of the visible spectra.

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Summarize the light-dependent reactions. What are
the reactants and products?
Reactants H2O ADPP NADP Products O2
ATP NADPH
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What reactions make up the Calvin cycle ( or
light independent reactions)?

• CO2 sugar
• ATP ADP P
• NADPH NADP

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What is the function of NADPH?

• It traps energy from sunlight into a chemical
  form
• NADPH holds 2 high energy electrons along with a
  hydrogen ion (H)

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How is light converted into chemical energy
during photosynthesis?

• In the light dependent reactions chloroplasts use
  light and H2O to change ADP and NADP to O2 ,
  ATP, and NADPH
• In the Calvin cycle or light independent reaction
  CO2 is changed into high energy sugar by using
  the energy in ATP an NADPH

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Based on the lab experiment, can the complete
process of photosynthesis take place in the dark?
Explain your answer.

• No, because ATP and NADPH wont be produced to be
  used in the calvin cycle.

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List factors that affect photosynthesis

• Amount of water
• Temperature
• Intensity of light

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Factors affecting photosynthesis Three factors
can limit the speed of photosynthesis light
intensity, carbon dioxide concentration and
temperature. Light intensity Without enough
light, a plant cannot photosynthesize very
quickly, even if there is plenty of water and
carbon dioxide. Increasing the light intensity
will boost the speed of photosynthesis.           
                                                  
                                    Carbon
dioxide concentration Sometimes photosynthesis is
limited by the concentration of carbon dioxide in
the air. Even if there is plenty of light, a
plant cannot photosynthesize if there is
insufficient carbon dioxide.                 
                                Temperature If it
gets too cold, the rate of photosynthesis will
decrease. Plants cannot photosynthesize if it
gets too hot. If you plot the rate of
photosynthesis against the levels of these three
limiting factors, you get graphs like the ones
above. In practice, any one of these factors
could limit the rate of photosynthesis.
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Photoinhibition reduction in photosynthesis as a
result of low lightEnzymes are less active at
low temperatures and destroyed at high
temperatures
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As carbon dioxide increases this is beneficial
for photosynthesis.However because it is a
greenhouse gas increased carbon dioxide will
cause more infrared heat energy to be trapped in
the earths atmosphere and cause a increase in
temperature. An increase in temperature
decreases photosynthesis
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Cellular Respiration and Fermentation

• Chemical process where food energy is broken down
  to release energy.
• Cellular respiration when oxygen is used
• Fermentation releases energy from food without
  using oxygen.
• http//www.youtube.com/watch?vnGRDa_YXXQAfeature
  player_embedded

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Write the overall equation for cellular
respiration

• C6H12O6 6O2 Usable energy (ATP) 6CO2
  6H2O

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Glycolysis followed by cellular respiration
4.
3.
5.
2.
1.
6.
7.
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What are the three main stages of cellular
respiration called?

• Glycolysis
• Krebs cycle
• Electron transport chain

Where does the glucose for cellular respiration
come from?

• Food!

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How do you know that this series of reactions
occurs in the presence of oxygen?

• A large amount of energy is released.

What does glycolysis supply to the Krebs cycle
and to the electron transport chain?

• Pyruvic acid
• NADH

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What stages of cellular respiration occur in the
mitochondria?

• Krebs cycle and Electron Transport Chain

Where in the cell does glycolysis take place?

• cytoplasm

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Glycolysis is an energy consuming process and an
energy releasing process, explain

• 2 ATP are used
• 4 ATP are produced

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What does glycolysis supply to the Krebs cycle?
What does it supply to the electron transport
chain?

• Pyruvic acid
• NADH (electrons)

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The Krebs cycle is aerobic what does that mean?

• Requires oxygen

Where does the Krebs cycle take place?

• mitochondria

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In the Krebs cycle pyruvic acid is broken down
into what?

• Carbon dioxide

How many ATP molecules are generated for every
one turn of the Krebs cycle?

• 1ATP

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How many ATP molecules are generated for every
one turn of the Krebs cycle?

• 1ATP

Where is the most of the chemical energy in
pyruvic acid transferred as a result of the Krebs
cycle?

• to NADH

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Where does the electron transport chain take
place?

• Mitochondria

What builds up on the intermembrane space of the
mitochondria?

• H ions

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What happens to the ATP synthases spins?

• Changes ADP to ATP

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How many ATP molecules total are produced from
glycolysis, the Krebs cycle, and the electron
transport chain?

• 36 net
• 38 total

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Website

• http//www.sumanasinc.com/webcontent/animations/co
  ntent/cellularrespiration.html lesson with
  questions embedded throughout

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• Fermentation questions

Why is the process of cellular respiration and
the process of fermentation discussed in the same
chapter? They are ways of releasing energy from
pyruvic acid made in glycolysis. What does
anaerobic mean? Without oxygen What are two
type of fermentation? Alcoholic and lactic acid
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alcohol
CO2
NAD
Pyruvic acid
NADH
Lactic acid
NAD
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What is the point of producing the NAD? To keep
glycolysis happening Why types of organisms do
alcoholic fermentation? How have humans
benefited? Microorganisms like yeast (think
bread) What types of cells in humans do lactic
acid fermentation? When? How would you know?
Muscles during bursts of activity when oxygen
isnt available feel the lactic acid burn!
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Cellular respiration Using stored in glycogen
Cellular respiration Breaking down fat
stored ATP
Lactic acid fermentation
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• What does breathing hard during after exercise
  have to do with cellular respiration?
• It provides oxygen to your cells.
• If someone is exercising for weight control how
  long must they exercise and why?
• More then 20 minutes to start to burn fat

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CHEMICAL SYMBOLS

• C CARBON
• O OXYGEN
• H HYDROGEN

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Comparing Photosynthesis Cellular Respiration

• Photosynthesis
• Light energy 6CO2 6H2O C6H12O6 6O2
• Purpose Energy Storage in bonds of glucose sugar
• Reactants 6CO2 6H2O
• Products C6H12O6 6O2
• Location Chloroplasts
• Happens in plants
• Cellular Respiration
• C6H12O6 6O2 Usable energy (ATP) 6CO2
  6H2O
• Purpose Energy release
• Reactants C6H12O6 6O2
• Products 6CO2 6H2O
• Location Mitochondria
• Happens in plants and animals

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CHEMICAL FORMULAS

• CO2 CARBON DIOXIDE
• One carbon two oxygen
• 6H2O WATER
• 6 molecules of two hydrogen one oxygen
• C6H12O6 GLUCOSE SUGAR
• Six carbon, twelve hydrogen, six oxygen
• 6O2 OXYGEN
• 6 molecules of two oxygen

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• Cell Respiration rap http//www.youtube.com/watch
  ?vvlZZUtpyCgQfeaturerelatedsafety_modetruepe
  rsist_safety_mode1
• Glucose sugar sugar http//www.youtube.com/watch?
  vjJvAL-iiLnQfeaturerelatedsafety_modetrueper
  sist_safety_mode1
• Photosynthesis rap http//www.youtube.com/watch?v
  Wi60tQa8jfEfeaturerelatedsafety_modetruepers
  ist_safety_mode1