Lab Exam #2 Flashcards
photo lab #1:
chlorophyll extraction and absorption spectrum
mechanism
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
photo lab #1:
chlorophyll extraction and absorption spectrum
independent variable
wavelength of light
photo lab #1:
chlorophyll extraction and absorption spectrum
dependent variable
absorbance
absorption of energy at the wavelength
photo lab #1:
chlorophyll extraction and absorption spectrum
range of visible light
400-700 nm
photo lab #1:
chlorophyll extraction and absorption spectrum
blue light wavelength
400-450 nm
photo lab #1:
chlorophyll extraction and absorption spectrum
green light wavelength
550 nm
photo lab #1:
chlorophyll extraction and absorption spectrum
red light wavelength
650-700 nm
photo lab #1:
chlorophyll extraction and absorption spectrum
most important process in biosphere carried out by photosynthetic autotrophs:
conversion of light energy to ATP
reducing carbon in CO2 –> drives conversion of CO2 + H20 –> sugar
photo lab #1:
chlorophyll extraction and absorption spectrum
relationship b/n energy and wavelength
inversely proportional
wavelength increase = energy decrease
wavelength decrease = energy increase
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.
higher
photo lab #1:
chlorophyll extraction and absorption spectrum
photon energy absorbed by chlorophyll permits removal of ____ from water (producing ____ and _____).
electrons
oxygen
protons
photo lab #1:
chlorophyll extraction and absorption spectrum
shuttling of electrons and protons drives ___ and reduces ___.
ATP Synthesis
CO2
photo lab #1:
chlorophyll extraction and absorption spectrum
does changing pigment [ ] substantially alter position of peaks (wavelength)?
No; changing pigment [ ] doesn’t alter wavelength position.
photo lab #1:
chlorophyll extraction and absorption spectrum
does changing pigment [ ] substantially alter height of peaks (absorbance)?
Yes; changing pigment [ ] changes absorbance.
photo lab #1:
chlorophyll extraction and absorption spectrum
what is relationship b/n pigment [ ] & height of peaks?
direct relationship
(linear)
As pigment [ ] increases = absorbance/height of peaks increases
photo lab #1:
chlorophyll extraction and absorption spectrum
is wavelength or absorbance more useful in identifying substance?
position of peaks (wavelength)
different substances have pigments that absorb different wavelengths of light
photo lab #1:
chlorophyll extraction and absorption spectrum
chlorophyll a & b absorb ____ light
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)
photo lab #1:
chlorophyll extraction and absorption spectrum
carotene absorbs ____ light
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).
photo lab #1:
chlorophyll extraction and absorption spectrum
what would be consequences to photosynthesis if chlorophyll was transparent? Absorption spectrum?
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
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?
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
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?
exploited their different solubilities in 3 solvents (ether, methanol, ethanol)
chlorophyll a –> petroleum ether
chlorophyll b –> methanol
carotene –> ethanol
quantitative changes in populations lab:
given proper conditions, populations of living things ___
increase numerically
quantitative changes in populations lab:
3 patterns of pop. increase
linear growth
unrestricted exponential growth
logistic growth
quantitative changes in populations lab:
linear growth
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
quantitative changes in populations lab:
unrestricted exponential growth
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
quantitative changes in populations lab:
logistic growth
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
quantitative changes in populations lab:
limiting factors
factors that restrict the carrying capacity of an environment
ex. resource, food, space limitations, competition, predation, pollution
quantitative changes in populations lab:
carrying capacity
of individuals in a population that an environment can support indefinitely
quantitative changes in populations lab:
3 phases in logistic growth
lag phase
log phase
stationary phase
quantitative changes in populations lab:
lag phase of logistic growth
births > # deaths
slow growth bc small pop. is multiplying
quantitative changes in populations lab:
log phase of logistic growth
births»_space; # deaths
rapid growth bc much larger pop. is multiplying
quantitative changes in populations lab:
stationary phase of logistic growth
births = # deaths
growth rate is 0
pop. stays at carrying capacity
limiting factors prevent pop. from exceeding carrying capacity
quantitative changes in populations lab:
dN/dt for logistic growth condition:
N «_space;K
dN/dt = rN
quantitative changes in populations lab:
dN/dt for logistic growth condition:
N is approaching K
dN/dt approaches 0
quantitative changes in populations lab:
dN/dt for logistic growth condition:
N = K
dN/dt = 0
quantitative changes in populations lab:
dN/dt for logistic growth condition:
N > K
dN/dt is negative (pop. is declining)