lecture 9_pg.64-75

Question 1

Kranz anatomy

Answer 1

specialized leaf anatomy of C4 species with photosynthetic bundle sheath cells surrounding vascular bundles

Question 2

plasmodesmata

Answer 2

N/A

Question 3

C4 photosynthesis

Answer 3

photosynthetic pathway in which the first step of CO2 assimilation is the carboxylation of phosphoenolpyruvate (PEP) by PEP carboxylase during the day; the first product is oxaloacetic acid (OAA), a four-carbon intermediate

Question 4

PEP carboxylase

Answer 4

N/A

Question 5

carbonic anhydrase

Answer 5

enzyme catalyzing the interconversion of HCO3- and CO2

Question 6

bundle sheath cells

Answer 6

cells surrounding the vascular bundle of a leaf

Question 7

oxygenation

Answer 7

the binding of O2 to a substrate, without changing the redox state of O (e.g., RuBP by RuBisCO); it also refers to the addition of O2 to a medium (e.g., water)

Question 8

photorespiration

Answer 8

production of CO2 in the metabolic pathway that metabolizes the products of the oxygenation reaction catalyzed by RuBisCO

Question 9

CO2-compensation point

Answer 9

CO2 concentration at which the rate of CO2 assimilation by photosynthesis is balanced by the rate of CO2 production by respiration

Question 10

quantum yield

Answer 10

moles of CO2 fixed or O2 evolved in photosynthesis, or electrons transported in the photosynthetic membrane, per mole of quanta absorbed; in the context of gas exchange often restricted to the linear, light-limited part of the photosynthesis-irradiance curve; when measuring chlorophyll fluorescence, it refers to the full range of photosynthetic irradiance

Question 11

stomatal conductance/resistance

Answer 11

conductance/resistance for transport of CO2 or water vapor through the stomata

Question 12

photosynthetic nitrogen-use efficiency

Answer 12

rate of photosynthesis expressed per unit (organic) nitrogen in the photosynthesizing tissue

Question 13

glycine decarboxylase

Answer 13

N/A

Question 14

atmospheric CO2 concentration

Answer 14

280 ppm in pre-industrial times, and has risen to 400 ppm (as of May 2013), with the increase largely attributed to anthropogenic sources

Question 15

CO2-concentrating mechanism

Answer 15

N/A

Question 16

convergent evolution

Answer 16

process whereby, in organisms that are not closely related, similar traits evolve independently as a result of adaptation to similar environments or ecological niches