Overview of Photosynthesis Flashcards
(32 cards)
What is photosynthesis?
The process by which plants and some organisms convert light energy into chemical energy, producing oxygen and glucose from CO₂ and water.
What are the two main types of reactions in photosynthesis?
Reduction and oxidation reactions, which occur simultaneously.
What types of organisms carry out photosynthesis?
Both prokaryotes and eukaryotes.
Where does photosynthesis take place?
It occurs almost everywhere sunlight is available to serve as a source of energy, such as in the ocean (up to 100m deep) and in moist, warm environments on land.
What are the three types of energy involved in photosynthesis?
Light energy, chemical energy, and heat energy.
What are redox reactions?
Chemical reactions in which electrons are transferred from one reactant to another.
What is a reduction reaction?
A reaction in which a substance gains an electron, reducing the positive charge of the atom.
What is an oxidation reaction?
A reaction in which a substance loses an electron and the energy the electron carries, increasing the positive charge of the atom.
What happens to CO₂ in photosynthesis?
CO₂ is reduced to form carbohydrate molecules.
What is the light-dependent stage of photosynthesis?
The process where sunlight energy is captured into usable chemical forms (NADPH and ATP) via chlorophyll.
What is the role of chlorophyll in photosynthesis?
Chlorophyll absorbs sunlight and drives electrons through the photosynthetic electron transport chain.
What is the photosynthetic electron transport chain?
A series of redox reactions that transfer electrons from a donor to an acceptor, producing NADPH and ATP.
Where do the electrons used in the light-dependent reactions come from in plants?
From water molecules, releasing oxygen as a byproduct.
What energy sources are used in the Calvin Cycle?
ATP and NADPH are used to build carbohydrates from CO₂.
What is the Calvin Cycle?
A light-independent process where CO₂ is reduced to synthesize carbohydrates using ATP and NADPH as energy sources.
What is a chloroplast?
A plastid in plant cells containing chlorophyll, where photosynthesis occurs.
What is the structure of a chloroplast?
Bound by two membranes, it contains thylakoids and stroma.
What are thylakoids?
Highly folded membranous structures within chloroplasts where the light-dependent reactions occur; they enclose a space called the lumen.
What are grana in chloroplasts?
Interlinked stacks of thylakoids.
What is the lumen in a chloroplast?
The fluid-filled compartment enclosed by the thylakoid membrane.
What is the stroma in a chloroplast?
The region that surrounds the thylakoids, where the Calvin Cycle takes place.
What is the role of pigments in photosynthesis?
Pigments are molecules that absorb some wavelengths of visible light.
Why does chlorophyll appear green?
Chlorophyll reflects green light and absorbs blue and red light.
What is the major light-absorbing pigment in eukaryotes and cyanobacteria?
Chlorophyll
