Chapter 7: Photosynthesis: using light to make food
___________ reacts with ozone to turn it into ____________.
Chlorine O2
Refer to Figure 7.8 on page 114 in your textbook. What molecules do the two people at the top of the platforms represent?
They represent primary electron acceptors.
A plant uses the products of the Calvin cycle for which of the following?
To make starch. To make cellulose. To make molecules used in protein synthesis
which of the following substances provides the majority of the atoms that make up the sugar produced by photosynthesis
carbon dioxide
C6H12O6 becomes oxidized in this process
cellular respiration
overall, this process in exergonic
cellular respiration
A plant's leaves are the primary site of photosynthesis. A plant's leaves would be expected to have a large amount of ____________.
chlorophyll
true or false: during photosynthesis CO2 is split to release oxygen gas
during photosynthesis H2O is split to release oxygen gas
true or false: a photoautroph is a type of heterotroph that uses solar energy to produce sugars.
false a photoautroph is a type of autotroph that uses solar energy to produce sugars.
True or false: Red wavelengths of light have more energy than purple wavelengths of light.
false: Red wavelengths of light have less energy than purple wavelengths of light.
a student has been shrunk fit inside the thylakoid space of a granum. how many leaves of phospholipids would he or she need through to get completely out of the mesophyll cell?
8
The Calvin cycle is also referred to as the light-independent reactions. Briefly explain why referring to the chemical reactions of the Calvin cycle as the light-independent reactions is only partially accurate.
Although the chemical reactions of the Calvin cycle do not directly depend on solar energy, the reactions do depend on the products produced by the light reactions.
Briefly explain what would happen to the levels of NADPH and ATP within the stroma if the passage of electrons to the primary electron acceptor of photosystem I were inhibite
Because the continuous passing of electrons along the electron transport chain powers the production of ATP, ATP production would stop. Additionally, because the electron transport chain links photosystem II to photosystem I, any interruption in the transport chain would also halt NADPH production.
Complete the Venn diagram that compares C4 with CAM photosynthesis.
C4: Keeps the stomata closed most of the time during hot and dry periods. Continues to produce sugar because of an enzyme that has a high affinity for CO2 even when CO2 is low. CAM: Opens the stomata only at night to minimize water loss. Both: Both are adaptations to photosynthesis in hot and/or dry climates.
A toxin is found to inhibit the uptake of CO2 into plant leaves. This toxin would most directly affect the ____________.
Calvin cycle
True or false: Each turn of the Calvin cycle produces one molecule of glucose.
False, one turn of the Calvin cycle makes a 3-carbon sugar called G3P. It would take two turns of the Calvin cycle to make a 6-carbon glucose.
True or false: The Kyoto Protocol of 1997 eliminated the use of CFCs by all participating countries. If false, make it a correct statement.
False, the Montreal Protocol eliminated the use of CFCs by all participating countries.
List three benefits of photosynthetic products to humans.
Food, fuel, and removal of CO2 from the atmosphere
A botanist discovers a new plant species in the Amazon rainforest that has blue leaves. Briefly explain what can be inferred about the pigments in the leaves of this plant.
It can be assumed that the pigments in this plant absorb all wavelengths of the visible light spectrum except blue.
Figure 7.7A on page 113 clearly depicts the events that occur when a pigment absorbs a photon of light. If a substance somehow kept the boosted electron from falling back to its ground state, would light and heat still be released in the same amount? Briefly explain your answer.
No, if an electron were kept from falling back to its ground state, the energy would not be given off as light and heat in that moment.
Complete the Venn diagram that compares photosystem I with photosystem II.
Photosystem I: Produces NADPH. Photosystem II: Produces ATP. Splits water Both: Consist of two complexes of pigments. Linked by an electron transport chain
The Calvin cycle is cyclic because
RuBP is regenerated in the final chemical reaction.
What is the overall effect of increased CO2 levels on poison ivy growth? Refer to Figure 7.13B on page 119 in your textbook.
The effect has been a significant increase in the growth of poison ivy.
What links photosystem I with photosystem II?
The electrons passed between the two photosystems.
If a scientist removes the pair of chlorophyll a molecules from the reaction-center complex, then which of the following consequences would be most likely to occur?
The primary electron acceptor would capture boosted electrons from the light-harvesting complex.
Briefly explain what links the two stages of photosynthesis with each other.
The two stages of photosynthesis are linked by the ATP and NADPH produced in the light reactions. ATP and NADPH are used in the dark reactions to power the synthesis of sugar.
A common misconception is that the greenhouse effect is bad. Briefly explain why this is not necessarily true.
Without the greenhouse effect, the Earth would be significantly cooler and not as hospitable to life as we know it.
The two complexes of pigments that constitute a photosystem include _____________________ and the _______________________.
light-harvesting complex reaction-center complex
_______________ is the process by which a plant adds O2 to RuBP instead of CO2.
photorespiration
CO2 is reduced in this process
photosynthesis
overall, this process is endergonic
photosynthesis
A new bacterium is discovered in Lake Superior. Scientists are able to determine that these bacteria produce oxygen gas. What is likely to be true about these organisms?
the bacteria is probably a phototroph and perform photosynthesis
