Chapter 10 Flashcards
Define Autotroph.
Autotrophs have the ability to make their own food via photosynthesis.
How do plants take in atmospheric CO2? How do plants absorb water?
Plants take in CO2 by the openings under their leaves called stomata. They absorb water through the roots.
Define transpiration.
When water evaporates and as it exits through the leaves, it sucks up more water into its roots.
During transpiration, how does water travel through plants?
Water travels through plants vascular cells.
Not a question just information.
Photosynthetic organisms use sunlight to oxidize water
into oxygen, and reduce carbon dioxide into glucose. This is the opposite as cellular
respiration, where oxygen is reduced into water, and glucose is oxidized to form carbon
dioxide!
Define the five characteristics and attributes of a chloroplast: chlorophyll, stroma, thylakoids, grana, and mesophyll cells.
Chlorophyll are light absorbing pigments which helps convert solar energy into chemical energy.
Stroma is a viscous liquid inside chloroplasts.
Thylakoids are folded interconnected membranous sacs.
Grana are stacks of thylakoids.
Mesophyll cells are what chloroplasts are found in (high concentrations of chloroplasts.
Chloroplasts can be found in multiple types of plant tissues. Where are they most abundantly found?
They are mostly found in the leaves of plants.
Name the type of cell that regulate the opening of the leaves’ stomata.
The cell that regulates the opening of the leaves’ stomata are called guard cells
Summarize what occurs during the light reactions of photosynthesis.
Energy from light splits water and drives the synthesis of ATP and NADPH
Summarize what occurs during dark reactions of photosynthesis.
ATP is energy required to synthesize sugar, NADPH provides electrons to reduce CO2 into glucose. This occurs in the stroma.
Light consists of high-speed particles called ____? These high-speed particles are packets of what type of energy?
Called photons. Photons are packets of electromagnetic energy.
What are the three pigments found in chloroplasts that absorb different wavelengths? Describe which colors each pigment absorbs and reflects.
Chloroplasts contain chlorophyll a, chlorophyll b, and carotenoids. Chlorophyll absorbs violet, blue and yellow, orange, red, and they reflect green light. Carotenoids absorb violet, blue, green and reflect yellow, orange, and red light.
Write out the chemical equation for the splitting of water.
2H2O —> 4H+ + 4e- + O2
(Not a question, just information!) Electrons move from a ground state (low energy) to an excited state (high energy). These electrons are harnessed in a network of pigments, referred to as a photosystem
Define photosystem. What is a pigment’s role in a photosystem, and how does it relate to an electron’s energy state?
Photosystem is a molecular light-capture device. A pigment receives an energy boost by the impact of photons. This energy is used to excite electron to a higher energy state (resonance)
Explain how energy is transferred through photosystem II, including the role of electrons.
Sunlight striking the chlorophyll molecules in photosystem II transfers energy, which eventually is used to excite the electron. This is known as resonance.
When is the potential energy of the excited electron converted to kinetic energy? What is this kinetic energy used for?
The potential energy of the excited electron is converted to kinetic energy as it “falls” down the chain. This kinetic energy is used to pump hydrogen ions (H+) across the thylakoid membrane against their concentration gradient.
Define proton motive force.
The proton motive force is the large concentration gradient of the H+ on one side of the membrane results in high potential energy.
In which membrane of the chloroplasts is ATP synthase found?
Thylakoid
(Not a question, just information!) The way ATP is created through chemiosmosis with ATP synthase is very, very similar to the way it works in cellular respiration. Hydrogen ions are
used by moving down a concentration gradient, through ATP synthase, synthesizing ATP by oxidative phosphorylation. Other than location, the main difference is then where the ATP goes.
Explain the electron’s travel and role in Photosystem I.
Sunlight is absorbed by chlorophyll molecules in photosystem I, and its excites electrons to a higher energy state (Resonance). When the electron at the reaction is energized at center chlorophylls called P700 in Photosystem I. It is transferred to the primary electron acceptor and “trapped” in its high energy state.
What is the P number for the center chorophylls in photosystem I and II? (Hint: An example would be P320, replacing 320 with the correct number for each system.)
P700
What specifically carries the high-energy electron from the end of photosystem I to the Calvin cycle?
NADPH
Explain the roles of the two electron transport chains working during the light reactions.
One provides a link between the two photosystem during which ATP is made. The second one produced NADPH, an energized molecule (carrying electron) used in the dark reactions (Calvin Cycle).
