Lab Exam #2

Question 1

photo lab #1:
chlorophyll extraction and absorption spectrum

mechanism

Answer 1

chlorophyll a & b, and carotene sort photons
some energy transferred from photon energy into chemical energy
source of electrons is water
remove electrons from water and build glucose

Question 2

photo lab #1:
chlorophyll extraction and absorption spectrum

independent variable

Answer 2

wavelength of light

Question 3

photo lab #1:
chlorophyll extraction and absorption spectrum

dependent variable

Answer 3

absorbance

absorption of energy at the wavelength

Question 4

photo lab #1:
chlorophyll extraction and absorption spectrum

range of visible light

Answer 4

400-700 nm

Question 5

photo lab #1:
chlorophyll extraction and absorption spectrum

blue light wavelength

Answer 5

400-450 nm

Question 6

photo lab #1:
chlorophyll extraction and absorption spectrum

green light wavelength

Answer 6

550 nm

Question 7

photo lab #1:
chlorophyll extraction and absorption spectrum

red light wavelength

Answer 7

650-700 nm

Question 8

photo lab #1:
chlorophyll extraction and absorption spectrum

most important process in biosphere carried out by photosynthetic autotrophs:

Answer 8

conversion of light energy to ATP

reducing carbon in CO2 –> drives conversion of CO2 + H20 –> sugar

Question 9

photo lab #1:
chlorophyll extraction and absorption spectrum

relationship b/n energy and wavelength

Answer 9

inversely proportional

wavelength increase = energy decrease
wavelength decrease = energy increase

Question 10

photo lab #1:
chlorophyll extraction and absorption spectrum

light with a wavelength of 450 nm has _______ energy than light with a wavelength of 650 nm.

Answer 10

higher

Question 11

photo lab #1:
chlorophyll extraction and absorption spectrum

photon energy absorbed by chlorophyll permits removal of ____ from water (producing ____ and _____).

Answer 11

electrons
oxygen
protons

Question 12

photo lab #1:
chlorophyll extraction and absorption spectrum

shuttling of electrons and protons drives ___ and reduces ___.

Answer 12

ATP Synthesis

CO2

Question 13

photo lab #1:
chlorophyll extraction and absorption spectrum

does changing pigment [ ] substantially alter position of peaks (wavelength)?

Answer 13

No; changing pigment [ ] doesn’t alter wavelength position.

Question 14

photo lab #1:
chlorophyll extraction and absorption spectrum

does changing pigment [ ] substantially alter height of peaks (absorbance)?

Answer 14

Yes; changing pigment [ ] changes absorbance.

Question 15

photo lab #1:
chlorophyll extraction and absorption spectrum

what is relationship b/n pigment [ ] & height of peaks?

Answer 15

direct relationship
(linear)

As pigment [ ] increases = absorbance/height of peaks increases

Question 16

photo lab #1:
chlorophyll extraction and absorption spectrum

is wavelength or absorbance more useful in identifying substance?

Answer 16

position of peaks (wavelength)

different substances have pigments that absorb different wavelengths of light

Question 17

photo lab #1:
chlorophyll extraction and absorption spectrum

chlorophyll a & b absorb ____ light

Answer 17

chlorophyll a & b look green because they reflect green light

they absorb blue and red light

absorb light of wavelength 400-450 nm (blue) and 650-700 nm (red)

reflect light of wavelength 550 nm (green)

Question 18

photo lab #1:
chlorophyll extraction and absorption spectrum

carotene absorbs ____ light

Answer 18

carotene looks yellow-orange because reflects yellow-orange light

absorbs blue-green light

absorbs light at wavelength 450-500 nm (blue-green) but not light of wavelength 650-700 nm (red).

Question 19

photo lab #1:
chlorophyll extraction and absorption spectrum

what would be consequences to photosynthesis if chlorophyll was transparent? Absorption spectrum?

Answer 19

if chlorophyll is colorless –> reflects all wavelengths of light and absorbs no light

useless in photosynthesis bc couldn’t collect light and photosystems can’t transfer electrons

if chlorophyll doesn’t absorb light –> no energy to remove electrons from water –> no oxidation of water –> useless in photosynthesis

absorption spectrum would be flat line near zero absorbance across visible spectrum

Question 20

photo lab #1:
chlorophyll extraction and absorption spectrum

chlorophyll is green; how does this relate to absorption spectrum? how much photosynthesis would a plant carry out if it were illuminated by green light alone? by blue light? by red light?

Answer 20

chlorophyll is green bc reflects green light and absorbs blue and red light

green light is of little use in photosynthesis

blue and red light are of great use in photosynthesis

Question 21

photo lab #1:
chlorophyll extraction and absorption spectrum

what major property of chlorophyll a & b and carotenoids did we take advantage of in order to separate them from one another?

Answer 21

exploited their different solubilities in 3 solvents (ether, methanol, ethanol)

chlorophyll a –> petroleum ether
chlorophyll b –> methanol
carotene –> ethanol

Question 22

quantitative changes in populations lab:

given proper conditions, populations of living things ___

Answer 22

increase numerically

Question 23

quantitative changes in populations lab:

3 patterns of pop. increase

Answer 23

linear growth
unrestricted exponential growth
logistic growth

Question 24

quantitative changes in populations lab:

linear growth

Answer 24

pop. increases by set number each generation

N = ct + No

dN/dt = slope = c

rate of increase and slope are constant and independent of pop. size

Question 25

quantitative changes in populations lab:

unrestricted exponential growth

Answer 25

pop. increases by a fixed proportion

N = No e^(rt)

r: intrinsic rate of increase

dN/dt = slope = rN

slope & rate of increase are NOT constant – constantly changing

growth rate is proportional to pop. size
as pop size increases = growth rate increases

Question 26

quantitative changes in populations lab:

logistic growth

Answer 26

most realistic – occurs in environment where various factors restrict growth

dN/dt = slope = rN (K-N)/K

rate of increase influenced by how large N is in comparison to K
growth rate influenced by difference b/n carrying capacity and pop. size

Question 27

quantitative changes in populations lab:

limiting factors

Answer 27

factors that restrict the carrying capacity of an environment

ex. resource, food, space limitations, competition, predation, pollution

Question 28

quantitative changes in populations lab:

carrying capacity

Answer 28

of individuals in a population that an environment can support indefinitely

Question 29

quantitative changes in populations lab:

3 phases in logistic growth

Answer 29

lag phase
log phase
stationary phase

Question 30

quantitative changes in populations lab:

lag phase of logistic growth

Answer 30

births > # deaths

slow growth bc small pop. is multiplying

Question 31

quantitative changes in populations lab:

log phase of logistic growth

Answer 31

births&raquo_space; # deaths

rapid growth bc much larger pop. is multiplying

Question 32

quantitative changes in populations lab:

stationary phase of logistic growth

Answer 32

births = # deaths

growth rate is 0

pop. stays at carrying capacity

limiting factors prevent pop. from exceeding carrying capacity

Question 33

quantitative changes in populations lab:

dN/dt for logistic growth condition:
N &laquo_space;K

Answer 33

dN/dt = rN

Question 34

quantitative changes in populations lab:

dN/dt for logistic growth condition:
N is approaching K

Answer 34

dN/dt approaches 0

Question 35

quantitative changes in populations lab:

dN/dt for logistic growth condition:
N = K

Answer 35

dN/dt = 0

Question 36

quantitative changes in populations lab:

dN/dt for logistic growth condition:
N > K

Answer 36

dN/dt is negative (pop. is declining)