Unit 1, Module 3 Glossary Flashcards Preview

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Flashcards in Unit 1, Module 3 Glossary Deck (26):
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Autotrophs

Organisms that use light energy or chemical energy and inorganic molecules to synthesis complex organic molecules.

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Heterotrophs

Organisms that ingest and digest complex organic molecules, releasing the chemical potential energy stored in them.

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Chemoautotrophs

Autotrophs that use chemical energy

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Exergonic

Chemical or biochemical reaction that releases heat energy.

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Photoautotrophs

Autotrophs that use light energy.

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Nanometre

On thousandth of a micrometre, or one millionth of a millimetre.

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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.

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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.

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Granum

A stack of thylakoid membranes, found in a chloroplast.

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Stroma

Fluid filled matrix of chloroplasts. This is where the light-independent stage of photosynthesis takes place.

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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.

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Thylakoids

Inner membrane in chloroplast. Site of photosystems and ATP synthase.

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Photosystems

Group of photosynthetic pigments in the thylakoid membrane. Consists of primary reaction centre and accessory pigments.

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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.

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Photophosphorylation

The making of ATP from ADP and Pi in the presence of light.

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Electron carriers

Molecule that transfer electrons

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Electron acceptors

Chemicals that accept e
Extrinsic from another compound. They are reduced while acting as oxidising agents.

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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.

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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.

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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.

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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.

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Ribulase bisphosphate carboxylase-oxygenase (Rubisco)

Enzyme that catalysed the carboxylate on yo ribilase bisphosphate

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Glycerate-3-phosphate (GP)

Intermediate compound produced during the Calvin cycle in the light-independent stage of photosynthesis.

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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.

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Limiting factor

The factor that is present at the lowest or least favourable value.

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Photosynthometer

Used to measure the rate of photosynthesis by collecting and measuring the volume of oxygen produced in a certain time.