Unit 1, Module 3 Glossary Flashcards
Heterotrophs
Organisms that ingest and digest complex organic molecules, releasing the chemical potential energy stored in them.
Autotrophs
Organisms that use light energy or chemical energy and inorganic molecules to synthesis complex organic molecules.
Chemoautotrophs
Autotrophs that use chemical energy
Exergonic
Chemical or biochemical reaction that releases heat energy.
Photoautotrophs
Autotrophs that use light energy.
Nanometre
On thousandth of a micrometre, or one millionth of a millimetre.
Photosynthetic pigments
Molecules that absorb light energy. Each pigment absorbs a range of wavelengths in the visible region and has its own distinct peak of absorption. Other wavelengths are reflected.
Lamellae
A pair of membrane that. Contain chlorophyll. Intergranal lamellar in the chloroplasts link the thylakoids of one granum with the thylakoids of another granum.
Granum
A stack of thylakoid membranes, found in a chloroplast.
Stroma
Fluid filled matrix of chloroplasts. This is where the light-independent stage of photosynthesis takes place.
Light independent stage
Second stage of photosynthesis. Occurs in the strong of the chloroplasts. Involves using ATP, reduced NADP and carbon dioxide to make organic molecules.
Thylakoids
Inner membrane in chloroplast. Site of photosystems and ATP synthase.
Photosystems
Group of photosynthetic pigments in the thylakoid membrane. Consists of primary reaction centre and accessory pigments.
Primary pigment reaction centre
The primary photosynthetic pigments in a photosystem act as reaction centres. In PSI the primary pigment reaction centre is a molecule of chlorophyll a that has a peak absorption of 680nm. In PSII the pigment reaction centre is a molecule of another type of chlorophyll a that has an absorption peak of 700nm.
Photophosphorylation
The making of ATP from ADP and Pi in the presence of light.
Electron carriers
Molecule that transfer electrons
Electron acceptors
Chemicals that accept e
Extrinsic from another compound. They are reduced while acting as oxidising agents.
Chemiosmosis
The flow of hydrogen ions through ATP synthase enzymes, the force of this flow allows the production of ATP. Occurs across the thylakoid membrane during the light-dependent stage of photosynthesis.
NADP
Coenzyme involved in photosynthesis. It accepts hydrogen atoms from photolysis of water during the light-dependent stage and carries them to the light-independent stage.
Light independent stage
Second stage of photosynthesis. Occurs in the stoma of the chloroplasts, involves using ATP, reduced NADP and carbon dioxide to make organic molecules.
Ribulase bisphosphate (RuBP)
5-carbon compound, present in small amounts in the stroma of chloroplasts. It is a carbon dioxide acceptor. It is regenerated from triose phosphate.
Ribulase bisphosphate carboxylase-oxygenase (Rubisco)
Enzyme that catalysed the carboxylate on yo ribilase bisphosphate
Glycerate-3-phosphate (GP)
Intermediate compound produced during the Calvin cycle in the light-independent stage of photosynthesis.
Triose phosphate (TP)
3-carbon compound formed when a molecules of glycerate phosphate is reduced, during the Calvin cycle in the light-independent stage of photosynthesis.
Limiting factor
The factor that is present at the lowest or least favourable value.
Photosynthometer
Used to measure the rate of photosynthesis by collecting and measuring the volume of oxygen produced in a certain time.
