Unit 1, Module 3 Glossary

Question 0

Heterotrophs

Answer 0

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

Question 1

Autotrophs

Answer 1

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

Question 2

Chemoautotrophs

Answer 2

Autotrophs that use chemical energy

Question 3

Exergonic

Answer 3

Chemical or biochemical reaction that releases heat energy.

Question 4

Photoautotrophs

Answer 4

Autotrophs that use light energy.

Question 5

Nanometre

Answer 5

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

Question 6

Photosynthetic pigments

Answer 6

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.

Question 7

Lamellae

Answer 7

A pair of membrane that. Contain chlorophyll. Intergranal lamellar in the chloroplasts link the thylakoids of one granum with the thylakoids of another granum.

Question 8

Granum

Answer 8

A stack of thylakoid membranes, found in a chloroplast.

Question 9

Stroma

Answer 9

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

Question 10

Light independent stage

Answer 10

Second stage of photosynthesis. Occurs in the strong of the chloroplasts. Involves using ATP, reduced NADP and carbon dioxide to make organic molecules.

Question 11

Thylakoids

Answer 11

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

Question 12

Photosystems

Answer 12

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

Question 13

Primary pigment reaction centre

Answer 13

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.

Question 14

Photophosphorylation

Answer 14

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

Question 15

Electron carriers

Answer 15

Molecule that transfer electrons

Question 16

Electron acceptors

Answer 16

Chemicals that accept e

Extrinsic from another compound. They are reduced while acting as oxidising agents.

Question 17

Chemiosmosis

Answer 17

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.

Question 18

NADP

Answer 18

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.

Question 19

Light independent stage

Answer 19

Second stage of photosynthesis. Occurs in the stoma of the chloroplasts, involves using ATP, reduced NADP and carbon dioxide to make organic molecules.

Question 20

Ribulase bisphosphate (RuBP)

Answer 20

5-carbon compound, present in small amounts in the stroma of chloroplasts. It is a carbon dioxide acceptor. It is regenerated from triose phosphate.

Question 21

Ribulase bisphosphate carboxylase-oxygenase (Rubisco)

Answer 21

Enzyme that catalysed the carboxylate on yo ribilase bisphosphate

Question 22

Glycerate-3-phosphate (GP)

Answer 22

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

Question 23

Triose phosphate (TP)

Answer 23

3-carbon compound formed when a molecules of glycerate phosphate is reduced, during the Calvin cycle in the light-independent stage of photosynthesis.

Question 24

Limiting factor

Answer 24

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

Question 25

Photosynthometer

Answer 25

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