Photosynthesis Interactive
Name _____________________________________
1. Log on to Biomanbio.com
2. Save your game as you go along so you can return to it
later
3. Click on Respiration & Photosynthesis
-------------------------------------------------------------------------------------4. Click on ‘Leaf Anatomy’ and follow directions
a. What is the site of Photosynthesis? ________________________________
i.
Why wasn’t it the trunk of the tree? ______________________________
b. What cells are the primary cells responsible for photosynthesis in this leaf?
________________________________
c. What organelle performs photosynthesis? _________________________________
i.
Draw a picture of this organelle and label the thylakoids and stroma:
5. Click on ‘Light-Dependent Reactions’
a. Where do the light-dependent reactions take place? _______________________________________
i.
Steps of the light-dependent reactions, Photolysis:
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Step 1:
_________________________________________________________________________________________________
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Step 2 :
_________________________________________________________________________________________________
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As electrons travel down the electron transport chain (ETC), their energy is
used to pump hydrogen ions (protons) across the membrane into the
thylakoid space.
This results in a high concentration of H+ in the thylakoid space and a lower
concentration in the stroma. This causes a concentration gradient where H+
ions will want to move from high concentration to an area of low
concentration.
Name of the protein where the membrane lets H+ions through?
_________________________________________________
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The diffusion of H+ ions through ATP synthase allows ________________to be
produced!! {This ATP will be used during the next step, the
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________________________ ________________________, as an energy source to help
produce ___________________________________}.
The electrons continue down the ETC to Photosystem I.
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______________________ strikes Photosystem I causing the electrons to get excited again.
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Where do these excited electrons go?
________________________________________________________________________________________
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What are these electrons used for?
________________________________________________
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What is NADPH? _____________________________________________________________
■
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This means it is similar to ATP; it carriers energy
Theses electrons are carried to the stroma and will be used …
________________________________________________________________________________________
b. Summarize the basics of the light-dependent reactions:
i.
ii.
c. NOW! Make photolysis happen in the interactive!!
6. Click on the ‘Calvin Cycle’
a. What is Phase 1? ____________________________________
i.
A five carbon sugar is bound to a molecule of Carbon Dioxide (CO2) by the enzyme, Rubisco.
ii.
This forms 2 molecules of 3-phosphoglycerate
b. What is Phase 2? ______________________________________
i.
Each molecule of 3-phosphoglycerate is reduced to form G3P which requires energy from
____________ and electrons from _________.
ii.
2 molecules of G3P leave the Calvin Cycle, to form __________________
c. What is phase 3? _____________________________________
i.
The other 5 G3P molecules are used to regenerate RuBP so that the ______________________
_____________________ can continue.
ii.
These reactions require energy to occur. This comes from ATP produced from the
_______________________ ____________________________.
7. Quiz! (Not in the same order as the interactive site quiz)
a. Which part of the plant cell performs photosynthesis?
i.
Mitochondrion
ii.
Nucleus
iii.
Cell Wall
iv.
Chloroplast
b. What does light do when it strikes the chlorophyll molecules of photosystems I and II?
i.
Light causes glucose to be synthesized directly inside the chlorophyll molecules of the
photosystems.
ii.
Light causes the conversion of water into carbon dioxide, oxygen and electrons.
iii.
Light directly causes carbon dioxide to attach to RuBP during the carbon fixation stage of the
Calvin Cycle.
iv.
Light causes electrons to get excited (gain energy) and travel down an electron transport chain
embedded in the thylakoid membrane.
c. After light excites electrons and they leave Photosystem II to travel down the first electron
transport chain. How are these electrons replaced to Photosystem II?
i.
Water is split, and the electrons are given to the chlorophyll molecules of photosystem II.
ii.
Carbon dioxide is split, and the electrons are given to the chlorophyll molecules of photosystem II.
iii.
Oxygen is reduced and the electrons are given to the chlorophyll molecules of photosystem II.
iv.
Hydrogen undergoes fusion, and the electrons are given to the chlorophyll molecules of
photosystem II.
d. The splitting of water at photosystem II is known as ______________________ and results
in the production of _________________________.
i.
Photolysis; oxygen, hydrogen ions (protons), and electrons that are given to photosystem II.
ii.
Photosynthesis; carbon dioxide, G3P, and electrons that are given to photosystem II.
iii.
The Calvin cycle; carbon dioxide, G3P, and electrons that are given to photosystem II.
iv.
Chemiosmosis; oxygen, hydrogen ions (protons), glucose and electrons that are given to
photosystem II.
e. As the electrons travel from photosystem II down the first electron transport chain, their
energy is used to…
i.
Form oxygen, water, NADPH and glucose.
ii.
Pump hydrogen ions into the stroma, producing a concentration gradient that will later be used by
an enzyme to form ADP and phosphate.
iii.
Pump hydrogen ions into the thylakoid space, producing a concentration gradient that will later be
used by ATP synthase to form ATP.
iv.
Create glucose directly.
f. Why do hydrogen ions flow from the thylakoid space to the stroma through ATP synthase?
i.
They are pumped actively through ATP synthase. This uses up ATP energy and causes the
production of ADP and phosphate.
ii.
They flow through the Calvin cycle and produce light.
iii.
They flow passively from high to low concentration via facilitated diffusion. As they flow through
ATP synthase, the enzyme spins and produces ATP.
iv.
Hydrogen ions do not actually flow from the thylakoid space to the stroma. They flow the opposite
way.
g. After electrons get excited by light a second time (at photosystem I), where do they go?
i.
They travel down a second electron transport chain and are donated to NADP+, which becomes
NADPH (an electron carrier).
ii.
They travel down a second electron transport chain and are donated to ADP, which is then
converted to ATP.
iii.
They remain excited and then travel to photosystem II where they get even more excited until
they spontaneously combust.
iv.
They travel down a second electron transport chain and are donated to oxygen which then bonds
to hydrogen ions to form water.
h. Which products of the light-dependent reactions are used in the Calvin Cycle to help form
reduced organic compounds?
i.
i.
Oxygen, ATP, NADPH, and CO2
ii.
Water and CO2
iii.
Light, water and CO2
iv.
ATP and NADPH
What happens during the carbon fixation stage of the Calvin Cycle (light-independent
reactions)?
i.
The enzyme Rubisco attaches CO2 to RuBP, causing the formation of molecules of 3phosphoglycerate.
ii.
Energy from ATP and electrons from NADPH are used to reduce 3-phosphoglycerate to form
G3P molecules (which can be used to form other organic molecules such as glucose).
iii.
The remaining G3P molecules that have not exited the cycle are used to re-form RuBP through a
series of chemical reaction, so that the Calvin cycle can continue.
iv.
Oxygen is produced through this process.
j. What happens during the reduction stage of the Calvin Cycle (light-independent reactions)?
i.
The remaining G3P molecules that have not exited the cycle are used to re-form RuBP through a
series of chemical reactions, so that the Calvin cycle can continue.
ii.
Oxygen is produced through this process.
iii.
Energy from ATP and electrons from NADPH are used to reduce 3-phosphoglycerate to form
G3P molecules (which can be used to form other organic molecules such as glucose).
iv.
The enzyme Rubisco attaches CO2 to RuBP, causing the formation of molecules of 3phosphoglycerate.
k. What happens during the regeneration stage of the Calvin Cycle (light-independent reactions)?
i.
Oxygen is produced through this process.
ii.
The enzyme Rubisco attaches CO2 to RuBP, causing the formation of molecules of 3phosphoglycerate.
iii.
The remaining G3P molecules that have not exited the cycle are used to re-form RuBP through a
series of chemical reactions, so that the Calvin cycle can continue.
iv.
Energy from ATP and electrons from NADPH are used to reduce 3-phosphoglycerate to form
G3P molecules (which can be used to form other organic molecules such as glucose).