Wavelengths of light that are absorbed by chlorophyll trigger the light-dependent reactions.
Why do the absorption spectrum for chlorophyll and the action spectrum for photosynthesis coincide?
Energy in sunlight is transformed to chemical energy.
What happens when an excited electron is passed to an electron acceptor in a photosystem?
6 CO2 + 6 H2O > C6H12O6 + 6 O2
Which of these equations best summarizes photosynthesis?
water … NADPH
NADPH is a reactant in the Calvin cycle
The light reactions of photosynthesis use _____ and produce _____.
Which term describes ATP production resulting from the capture of light energy by chlorophyll?
The chemiosmotic hypothesis states that the flow of electrons through an electron transport chain generates a proton gradient that leads to the synthesis of ATP.
True or false? The chemiosmotic hypothesis states that the synthesis of ATP generates a proton gradient that leads to electron flow through an electron transport chain
A proton gradient across chloroplast and mitochondrial membranes drives ATP synthesis by the enzyme ATP synthase.
According to the chemiosmotic hypothesis, what provides the energy that directly drives ATP synthesis?
The channels formed by ATP synthase are specific for protons.
Which of the following particles can pass through the ATP synthase channel?
The region of ATP synthase that catalyzes ATP production protrudes out of, but does not span, the chloroplast membrane; the region that spans the membrane is an ion channel through which protons can pass.
True or false? The region of ATP synthase that catalyzes the production of ATP from ADP and inorganic phosphate spans the chloroplast membrane.
Oxygen is a by-product of the photosynthetic process.
Which process produces oxygen?
The light-dependent reactions
The light-dependent reactions use H2O and produce O2.
Which set of reactions uses H2O and produces O2?
The light-independent reactions turn CO2, a gas, into usable carbon in the form of sugars.
CO2 is unusable until plants have “fixed” this carbon into sugar
What is the importance of the light-independent reactions in terms of carbon flow in the biosphere?
The water molecules are split to replenish electrons in photosystem II, leaving behind protons, which are used to generate a proton gradient for the formation of ATP, and oxygen, which is released as a by-product.
True or false? The light-dependent reactions of photosynthesis use water and produce oxygen.
The NADPH produced by photosystem I is used to supply energy for the production of sugars during photosynthesis.
Which of the following molecules is the primary product of photosystem I?
They convert carbon dioxide to sugar.
All organisms use the sugars produced by photosynthesis to generate energy.
What is the biological significance of the light-independent reactions of photosynthesis?
The light-dependent reactions produce ATP and NADPH, which are then used by the light-independent reactions.
Which of the following statements best describes the relationship between the light-dependent and light-independent reactions of photosynthesis?
In the Calvin cycle, carbon dioxide is added to RuBP
Carbon fixation involves the addition of carbon dioxide to _____
NADPH supplies the electrons that reduce the phosphorylated 3-PGA.
After 3-PGA is phosphorylated, it is reduced by ____
Six carbon dioxide molecules are required to produce two G3P molecules, which can be combined to make one glucose molecule.
How many carbon dioxide molecules must be added to RuBP to make a single molecule of glucose?
In both systems, ATP is produced by chemiosmosis.
Which statement is most accurate concerning how photosystem II (PS II) compares to the electron transport chain (ETC) of mitochondria?
PS II > pheophytin > plastoquinone > cytochrome complex > plastocyanin > PS I > ferredoxin
In the final step of the Z scheme, electrons are transferred from ferredoxin to NADP+ (by the enzyme NADP+ reductase ) to produce NADPH.
According to the Z scheme, what is the path of electrons through photosystem I (PS I) and photosystem II (PS II)?
It becomes bonded to an organic compound.
What does it mean to say that CO2 becomes fixed?
Photosynthesis would occur but photorespiration would not.
Photosynthesis depends on binding of CO2, whereas photorespiration depends on binding of O2 to rubisco.
What would happen in a chloroplast containing an unusual form of rubisco that did not bind oxygen?
Sucrose is water soluble and used in respiration and sugar transport.
Which statement is most accurate concerning the solubility of starch or sucrose, as well as their use by plants?