Chapter 8 Bio Notes

waste products/reactants

____________ of cellular respiration are _________ used in photosynthesis

autotroph

“self feeders” make organic molecules entirely from non-living materials, producers, source of organic compounds

photoautotrophs

use light energy, carbon dioxide, water, minerals to make organic molecules

heterotrophs

“other feeders”, live on compounds produced by other organisms, some are decomposers, consumers of biospheres

chloropast

site of photosynthesis in eukaryotes, all green parts

mesophyll

chloroplast found in cells of the ____________, contains 30-40

mesophyll

interior tissue of the leaf

microscopic stomata

carbon dioxide and oxygen enters and exits through pores called __________________

veins

H20 travels to the leaves and sugar is exported out through ______

stroma

dense fluid of chloroplast

thylakoids

3rd membrane system composed of sacs, suspended within the stroma

granum

stacks of thylakoids

chlorophyll

green color of leaves, pigment in thylakoid membranes, absorbs light energy that drives synthesis of organic molecules

redox process

photosynthesis is a _________ process; reverses the direction of electron flow seen in cellular respiration

water/carbon dioxide

in photosynthesis ___________ is oxidized to form O2 and ______________ is reduced to sugar

endergonic reaction

photosynthesis is a endergonic or exergonic reaction?

light reactions

___________ occur in the thylakoids

calvin cycle

____________ occurs in the stroma

oxygen

__________ is a by product of photosynthesis

NADPH

reduced form of NADP+

calvin cycle

produces sugar using the CO2 from NADPH and ATP produced by light reactions

carbon fixation

carbon dioxide is incorporated into organic molecules during ___________ and reduced to form sugars

electromagnetic energy

light is a form of _________________

wavelength

distance between crests of electromagenetic waves

electromagnetic spectrum

consists of the entire range of radiation

visible light

segment consisting of 380-750 nm, can be detected as colors by the eye and powers photosynthesis

photons

light behaves in discrete particles, fixed quantity of energy, inverse to wavelength

pigments

substances that absorb visible light, absorb different wavelengths

reflects/transmits

leaves appear green because chlorophyll absorbs violet-blue and red light and _____________ green light

spectrophotometer

measures a pigments ability to absorb different wavelengths of light, light of wavelength is directed through a pigment solution, and the fraction of light transmitted at each wavelength is measured

absorption spectrum

graph that plots a pigments light absorption vs wavelength

chlorophyll a

the absorption spectrum of _______________ suggest that violet-blue and red light work best for photosynthesis

accessory pigments

include chlorophyll a, chlorophyll b, and carotenoids

action spectrum

graph that plots the rate of photosynthesis vs wavelength

profiles relative effectiveness of different wavelengths of radiation in driving photosynthesis

chlorophyll a

primary photosynthetic pigment, olive green

chlorophyll b

broadens spectrum used for photosynthesis, accessory pigment, blue

structural differences

________________ in chlorophyll result in different light absorption spectra

chlorophyll d and f

absorb greater wavelengths of light

cyanobacteria

use chlorophyll f as an accessory pigment can conduct photosynthesis in very shaded conditions

carotenoids

appear in various shades of yellow and orange, broaden spectrum used for photosynthesis, photoproduction, absorb light harmful to a and b chlorophyll

absorbs

when pigment _______ light, an electron is elevated from a ground state to an unstable

fluorescence

electrons fall back down to a ground state releasing photons that cause afterglow, if illuminated will give off light and heat

reaction enter complex

association of proteins holding a special pair of chlorophyll molecule and a primary electron acceptor

light harvesting complex

consists of various pigment molecules bound to proteins, transfer energy from a photon of light to chlorophyll a in the reaction center

photosystem

consists of a reaction center complex surrounded by light harvesting complexes embedded in thylakoid membrane

chlorophyll a

_____________ transfers an excited electron to the primary electron acceptor

intermembrane space

in mitochondria, protons are pumped to their _________________ and drive ATP synthesis as they diffuse back into mitochondrial matrix

thylakoid space

in chloroplast, protons are pumped into ____________ and drive ATP synthesis as they diffuse back into the stroma

low to high

light reaction electron flow pushes electrons from water (_____ potential energy) to NADPH (______ potential energy)

3, 3

for net synthesis of G3P, cycle must take ___ rounds fixing ___ molecules of CO2

photorespiration

metabolic process in plants that occurs when the enzyme RuBisCO oxygenates RuBP instead of fixing carbon dioxide (CO2). This process is the opposite of photosynthesis, which fixes CO2 and releases oxygen (O2)

metabolic relic

when oxygen goes down and carbon dioxide goes up, protect against damaging products of light reactions that accumulate when Calvin cycle slows due to reduced carbon dioxide levels

crassulacean acid metabolism/CAM

photosynthetic adaption to arid conditions, open stomata at night and incorporate carbon dioxide into organic acids, close stomata during day and carbon dioxide released forming organic acids used in calvin cycle

C4 Plants

carbon dioxide is fixed in mesophyll cells and the calvin cycle runs in a seperate bundle sheath cells, CO2 is incorporated into a 4 carbon compound using and enzyme that has a high affinity for carbon dioxide, stomata can be partially closed then moves into concentrated bundle-sheath cell, allowing calvin cycle to run without photorespiration

organic intermediates

both CAM and C4 pathways are similar as both use __________ before entering the calvin cycle

photosystem II

proteins and pigments absorb light and transfer electrons through chain until it reaches acceptor, has chlorophyll P680 (best absorbs 680nm wv)

P680 donates a pair of electrons after absorbing light energy resulting in an oxidized form of P680

enzyme catalyzes split of H2O into 2 electrons, 2 H and O which are transferred to P680 causing it to return to its initial stage

photosystem I

has P700 (best absorbs 700nm wv), oxidized form accepts electron from photosystem II returning it to its initial state

electrons then passed in a series of redox reactions through protein ferredoxin

electrons reach NADP+, reducing it to NADPH which carries it to Calvin Cycle

ferredoxin

primary electron acceptor of PSI

anabolic

calvin cycle is a (catabolic or anabolic) process that leads to a 6 carbon compound

step 1 of calvin cycle

carbon fixation into a 3 phosphoglycerate

carbon fixation

CO2 molecule covalently attached to 5 carbon (ribulose), 5-biphosphate catalyzed by enzyme ribulose 1, 5 bisphosphate carboxylase (rubisco) results in an unstable 6 carbon which turns into a 3 phosphoglycerate

step 2 of calvin cycle

conversion of 3 phosphoglycerate to glyceraldehydes 3 phosphoglycerate

step 2

3 phosphoglycerate converted to glyceraldehyde 3 phosphate by 2 reactions

1st reaction

enzyme 3 phosphoglycerate kinase in stroma catalyzes transfers of phosphoryl group from ATP to 3-phosphglycerate, yielding 1, 3-biphosphoglycerate

2nd reaction

NADPH donates electron in a reaction catalyzed by the chloroplast-specific isoenzyme of glyceraldehyde 3 phosphate dehydrogenase producing 3 phosphate and phosphate (Pi)

glyceraldehyde

most of ___________ 3-phosphate produced is used to regenerate ribulose 1, 5-biphosphate, rest is either converted to starch in chloroplast and stored for later use

step 3 of calvin cycle

regenerating ribulose 1, 5-biphosphate from triose phosphates, 3 carbon compounds formed in previous step to 5 carbon compounds ribulose 1, 5-biphosphate through a series of transformations with intermediates of 3, 4, 5, 6, and 7 carbon sugars

β-carotene

helps to protect photosystems by dissipating excess energy; also found in cells of carrots & oranges

carotenoids

lycopene (red color of tomato) and zeaxanthin (yellow of corn seeds)