Chapter 10 Flashcards
Chloroplasts are found mainly in the cells of the ______
Meseophyll, the tissue in the interior of the leaf
Stomata
Microscopic pores that regulate gas exchange
-CO2 in
-O2 out
Chlorophyll resides in…
The thylakoid membranes of the chloroplast.
The direct product of photosynthesis is actually…
A three carbon sugar that can be used to make glucose.
The O2 given off by plants is derived from H2O and not from CO2.
True
The light reactions are the steps of photosynthesis that convert solar energy to chemical energy.
True
NADP+
Electron acceptor (nicotinamide adenine dinucleotide phosphate)
Photophosphorylation
Using chemiosmosis to power the addition of a phosphate group to ADP
Carbon fixation
The initial incorporation of carbon into organic compounds.
Sites of light reactions
Thylakoids of the chloroplast
Site of Calvin cycle
Stroma
Wavelength
The distance between the crests of electromagnetic waves
Electromagnetic spectrum
The entire range of radiation
Visible light
Segment in electromagnetic spectrum from about 380 nm to 750 nm in wavelength
Pigments
Substances that absorb visible light
Spectrophotometer
Instrument used to measure the ability of a pigment to absorb various wavelengths of light
Absorption spectrum
Graph plotting a pigment’s light absorption vs wavelength
Chlorophyll a
The key light capturing pigment that participates directly in the light reactions
Chlorophyll b and carotenoids
Accessory pigments
Carotenoids’ important function
Photoprotection: Dissipate excessive light energy that would otherwise damage the chlorophyll.
As excited electrons fall back to the ground state, photons are given off, an afterglow called fluorescence.
True
A photosystem is composed of…
A reaction-center complex surrounded by several light-harvesting complexes
Reaction-center complex
Is an organized association of proteins holding a special pair of chlorophyll a molecules.
Each light-harvesting complex consists of…
Various pigment molecules bound to proteins.
The reaction-center complex also contains a molecule capable of accepting electrons and becoming reduced; called the primary electron acceptor.
Linear electron flow occurs during the light reactions of photosynthesis.
True
The cyclic electron flow uses
Photosystem 1 but not photosystem 2
-Is photoprotective
Chloroplast and mitochondria generate ATP by the same basic mechanism:
Chemiosmosis
The Calvin cycle is anabolic.
True
Carbohydrate produced directly from the Calvin Cycle
Glyceraldehyde 3-phosphate (G3P)
Five-carbon sugar to which CO2 attaches to in the carbon fixation phase of the Calving cycle.
Ribulose biphosphate (RuBP)
The enzyme that catalyzes the first step in the Calvin Cycle
Ribulose biphosphate carboxylase-oxygenase
(rubisco)
The most abundant protein in chloroplasts and on Earth.
For the net synthesis of one G3P molecule, the Calvin cycle consumes a total of _________ and ___________
Nine molecules of ATP
Six molecules of NADPH
C3 plants
Their first organic product of carbon fixation is a three carbon compound, 3-phosphoglycerate
Photorespiration consumes _______ while producing _______
O2, CO2
Photorespiration drains away as much bad 50% of the carbon fixed by the Calvin cycle.
True
C4 plants
Plants that form a four-carbon compound as its first product.
(Sugarcane and corn)
Bundle-sheath cells
Photosynthetic cells in C4 plants that are arranged into tightly packed sheaths around the veins of the leaf.
Enzyme present only in mesophyll cells
PEP carboxylase
CAM plants
Open their stomata during the night and close them during the day.
-To conserve water.
(Desert plants)
CAM stands for the mode of carbon fixation called
Crassulacean acid metabolism
