Bio Ch 7

Question 1

Photosynthesis

Answer 1

converts solar energy into the chemical energy of a carbohydrate

Question 2

Autotrophs

Answer 2

land plants, algae, and cyanobacteria are these because they produce their own food

Question 3

Heterotrophs

Answer 3

consumers; take in preformed organic molecules

Question 4

Stomata (singular = stoma)

Answer 4

carbon dioxide in the air enters a leaf through these small openings

Question 5

Chloroplasts

Answer 5

organelles that carry on photosynthesis

Question 6

Stroma

Answer 6

semifluid interior of the chloroplast

Question 7

Thylakoids

Answer 7

flattened sacs within the stroma of chloroplasts

Question 8

Grana (singular = granum)

Answer 8

stacks of thylakoids; looked like piles of seeds to early microscopists

Question 9

Chlorophyll

Answer 9

within the thylakoid membrane are this and other pigments that are capable of absorbing solar energy, the type of energy that drives photosynthesis

Question 10

Light reactions

Answer 10

only occur when solar energy is available (during daytime hours)

Question 11

Calvin Cycle Reactions

Answer 11

named for Melvin Calvin (discoverer); enzymatic reactions that reduce carbon dioxide to a carbohydrate in the stroma of chloroplasts

Question 12

Absorption spectrum

Answer 12

pigments in chloroplasts are capable of absorbing various portions of visible light

Question 13

Carotenoids

Answer 13

yellows/oranges; able to absorb light in the violet-blue-green range

Question 14

Photosystem

Answer 14

consists of a pigment complex (molecules of chlorophyll a, chlorophyll b, & the carotenoids) & electron acceptor molecules within the thylakoid membrane

Question 15

Noncyclic pathway

Answer 15

during light reactions, electrons usually follow this that begins with photosystem I

Question 16

Electron Transport Chain (ETC)

Answer 16

series of carriers that pass electrons from electron acceptor to reaction center

Question 17

ATP Synthase Complex

Answer 17

has a channel and a protruding ATP synthase; enzyme that joins ADP & P

Question 18

Chemiosmosis

Answer 18

method of producing ATP because ATP productions is tied to the establishment of an H+ gradient

Question 19

Climate change

Answer 19

expected rise in the average global temperature during the 21st century due to the introduction of certain gases into the atmosphere

Question 20

Carbon dioxide fixation

Answer 20

first step of the Calvin Cycle; molecule of carbon dioxide from the atmosphere is attached to RuBP, a 5-carbon molecule; result = two 3-carbon molecules

Question 21

RuBP carboxylase

Answer 21

protein that makes up about 20-50% of the protein content in chloroplasts

Question 22

C3 Plants

Answer 22

majority of land plants (ex. azaleas, maples, tulips); use the enzyme RuBP carboxylase to fix CO2 to RuBP in mesophyll cells

Question 23

Photorespiration

Answer 23

in the presence of light, oxygen is taken up and CO2 is released

Question 24

C4 Plants

Answer 24

fix CO2 to PEP (phosphoenolpyruvate, a C3 molecule) using the enzyme PEP carboxylase (PEPCase); result = oxaloacetate (C4 molecule); examples: sugarcane, corn, Bermuda grass

Question 25

CAM

Answer 25

crassulacean-acid metabolism; form of photosynthesis in succulent plants that separates the light-dependent and Calvin reactions by time