Exam 3-lecture 10 Flashcards
(32 cards)
Synthesis from light is
photosynthesis
What are the two pathways of photosynthesis
Light Reactions
Calvin cycle
what is light reaction? what happens to water and what happens to CO2
light energy converted to chemical energy as ATP and NADPH. water is oxidized and CO2 is released
what is the Calvin cycle? what happens to CO2
use ATP,NADPH, and CO2 to produce carbohydrates. CO2 is reduced
light is a form of
electromagnetic radiation
it comes in discrete packets called
photons
energy of a photon is proportional to its
wavelegnth
true or false. atom is more reactive in the excited state
true. energy from the photon boosts an electron into another shell
molecules that absorb specific wavelengths in the visible range of the spectrum are called
pigments
Types of pigments that absorb light energy used in photosynthesis are
chlorophyll (main plant pigment)
accessory pigments (absorb in red and blue regions, transfer the energy to chlorophyll)
Absorption of visible light by an isolated chlorophyll molecule results in
the release of heat and uorescence when the electron returns to its ground energy state
absorption of visible light by an antenna chlorophyll results in
the transfer of energy to an electron in a neighboring chlorophyll molecule
pigments are arranged in
antenna systems
what does a photosystem consists of
it consists of multiple antenna systems and their pigments surrounding a reaction center
reaction center is the
first chemical reaction of photosynthesis
Absorption of light energy by photosystem 2 allows for
electrons to be pulled from water to enter the photosynthetic electron transport chain
a second input of light energy by photosystem 1 produces
electron donor molecules capable of reducing NADP+
What is the Z scheme and what does it yield
Electrons extracted from water and transferred to NADPH, using energy from ps 2 and 1. yields NADPH, ATP and O2
The excited chlorophyll is a
reducing agent
how is the excited chlorophyll a reducing agent
ps 2 chlorophyll donates an electron to the photosynthetic ETC
ps 1 chlorophyll donates an electron to reduce NADP to NADPH
What are the two systems of electron transport
noncyclic and cyclic
noncyclic electron transport
produces NADPH and ATP
cyclic electron transport
an electron from an excited chlorophyll molecule in PS 1 cycles back to the same chlorophyll molecule. produces ATP only
CO2 is added to 5-c RuBP and then breaks down into
2 molecules of 3PGA