BIOL 1100 Ch 08: Photosynthesis

Question 1

absorption spectrum

Answer 1

range of wavelengths of electromagnetic radiation absorbed by a given substance

Question 2

antenna pigment

Answer 2

pigment molecule that directly absorbs light and transfers the energy absorbed to other pigment molecules

Question 3

Calvin cycle

Answer 3

light-independent reactions of photosynthesis that convert carbon dioxide from the atmosphere into carbohydrates using the energy and reducing power of ATP and NADPH

Question 4

carbon fixation

Answer 4

process of converting inorganic CO2 gas into organic compounds

Question 5

carotenoid

Answer 5

photosynthetic pigment (yellow-orange-red) that functions to dispose of excess energy

Question 6

chemoautotroph

Answer 6

organism that can build organic molecules using energy derived from inorganic chemicals instead of sunlight

Question 7

chlorophyll a

Answer 7

form of chlorophyll that absorbs violet-blue and red light and consequently has a bluish-green color; the only pigment molecule that performs the photochemistry by getting excited and losing an electron to the electron transport chain

Question 8

chlorophyll b

Answer 8

accessory pigment that absorbs blue and red-orange light and consequently has a yellowish-green tint

Question 9

chloroplast

Answer 9

organelle in which photosynthesis takes place

Question 10

electron transport chain

Answer 10

group of proteins between PSII and PSI that pass energized electrons and use the energy released by the electrons to move hydrogen ions against their concentration gradient into the thylakoid lumen

Question 11

granum

Answer 11

stack of thylakoids located inside a chloroplast

Question 12

heterotroph

Answer 12

organism that consumes organic substances or other organisms for food

Question 13

light harvesting complex

Answer 13

complex that passes energy from sunlight to the reaction center in each photosystem; it consists of multiple antenna pigments that contain a mixture of 300 to 400 chlorophyll a and b molecules as well as other pigments like carotenoids

Question 14

light-dependent reaction

Answer 14

first stage of photosynthesis where certain wavelengths of the visible light are absorbed to form two energy-carrying molecules (ATP and NADPH)

Question 15

mesophyll

Answer 15

middle layer of chlorophyll-rich cells in a leaf

Question 16

P680

Answer 16

reaction center of photosystem II

Question 17

photoact

Answer 17

ejection of an electron from a reaction center using the energy of an absorbed photon

Question 18

P700

Answer 18

reaction center of photosystem I

Question 19

photoautotroph

Answer 19

organism capable of producing its own organic compounds from sunlight

Question 20

photosystem

Answer 20

group of proteins, chlorophyll, and other pigments that are used in the light-dependent reactions of photosynthesis to absorb light energy and convert it into chemical energy

Question 21

photosystem II

Answer 21

integral protein and pigment complex in thylakoid membranes that transports electrons from water to the electron transport chain; oxygen is a product of PSII

Question 22

photosystem I

Answer 22

integral pigment and protein complex in thylakoid membranes that uses light energy to transport electrons from plastocyanin to NADP+ (which becomes reduced to NADPH in the process)

Question 23

reaction center

Answer 23

complex of chlorophyll molecules and other organic molecules that is assembled around a special pair of chlorophyll molecules and a primary electron acceptor; capable of undergoing oxidation and reduction

Question 24

primary electron acceptor

Answer 24

pigment or other organic molecule in the reaction center that accepts an energized electron from the reaction center

Question 25

reduction

Answer 25

gain of electron(s) by an atom or molecule

Question 26

stoma

Answer 26

opening that regulates gas exchange and water evaporation between leaves and the environment, typically situated on the underside of leaves

Question 27

spectrophotometer

Answer 27

instrument that can measure transmitted light and compute the absorption

Question 28

stroma

Answer 28

fluid-filled space surrounding the grana inside a chloroplast where the light-independent reactions of photosynthesis take place

Question 29

thylakoid

Answer 29

disc-shaped, membrane-bound structure inside a chloroplast where the light-dependent reactions of photosynthesis take place; stacks of thylakoids are called grana

Question 30

thylakoid lumen

Answer 30

aqueous space bound by a thylakoid membrane where protons accumulate during light-driven electron transport

Question 31

wavelength

Answer 31

distance between consecutive points of equal position (two crests or two troughs) of a wave in a graphic representation; inversely proportional to the energy of the radiation

Question 32

G3P

Answer 32

glyceraldehyde-3-phosphate
product of photosynthesis

Question 33

pigment

Answer 33

molecule that is capable of absorbing certain wavelengths of light and reflecting others (which accounts for its color)

Question 34

photon

Answer 34

distinct quantity or “packet” of light energy

Question 35

light-independent reaction

Answer 35

second stage of photosynthesis, through which carbon dioxide is used to build carbohydrate molecules using energy from ATP and NADPH

Question 36

cytochrome complex

Answer 36

group of reversibly oxidizable and reducible proteins that forms part of the electron transport chain between photosystem II and photosystem I