Define electrochemical gradient
is a gradient of electrochemical potential, usually for an ion that can move across a membrane. The gradient consists of two parts, the electrical potential and a difference in the chemical concentration across a membrane.
How ATP synthesis is coupled to an electron transport chain and electrochemical gradient
Distinguish between Autotrophic and Heterotrophic
Autotrophic- light is energy source
Heterotrophic- digesting organic compounds
Describe the location & structure of chloroplast
Location- embedded in the thylakoid membrane.
Structure- A double membrane surrounding a dense fluid called the stroma and elaborate ...view middle of the document...
----Absorption spectrum of chlorophyll a, is the pigment that participates directly in the light reactions.
Explain why the absorption spectrum for chlorophyll differs from the action spectrum for photosynthesis
The absorption spectrum indicates how much of each wavelength chlorophyll will absorb, whereas the action spectrum can tell us which off those wavelengths are most effective in photosynthesis.
List the wavelength of light that are most effective for photosynthesis
Violet-blue/ red light (while transmitting and reflecting green light)
Explain what happens when chlorophyll or accessory pigments absorb photons
When chlorophyll or accessory pigments absorb photons it causes the electrons from chlorophyll A to be picked up by an acceptor molecule and sent through the cytochrome system. Electrons from chlorophyll B and accessory pigments replace the electrons of chlorophyll A. When the transfer takes place, the reaction center becomes oxidized and the adjacent electron-acceptor molecule is reduced.
List the components of a photosystem 1 and 2
The Photosystem captures light with antennae pigments such as chlorophyll a and chlorophyll b, which funnels it light and gradually concentrates it down to a "reaction center." By the time the energy reaches the action center, it's very concentrated and needs somewhere to dump all the energy it has captured. The reaction center transfers the extra energy to enzymes, which further carry out work in the plant cell.
Chlorophyll turns light energy into chemical energy.
Trace electron flow through photosystem 1 and 2
Absorption of light excites an electron to a higher energy state, thus converting the energy of sunlight to potential chemical energy. The photosynthetic pigments are organized into photocenters in the thylakoid membrane, each of which contains hundreds of pigment molecules. The reaction center chlorophyll then transfers its high-energy electron to an acceptor molecule in an electron transport chain. High-energy electrons are then transferred through a series of membrane carriers, coupled to the synthesis of ATP and NADPH.
Photosystem II first absorbs energy, transfers excited electron to primary
electron acceptor; replaced by electron from water
Absorbs more light energy Primary electron acceptor
Compare cyclic and noncyclic electron flow and explain the relationship between these components and the light reactions
Comparison of cyclic and noncyclic- Only photosystem I is used in cyclic photophosphorylation where the electrons are passed back to the same photosystem, while non-cyclic phosphorylation uses both photosystems. Only ATP is produced in cyclic photophosphorylation, whereas both ATP and reduced NAD are produced in non-cyclic.
The relationship- Noncyclic electron flow begins in photosystem II:
-photosystem II is excited by light absorption
-e- derived from splitting water
-the e- is donated to electron transport...