AP Biology Chapter 10 Notes

What three factors contribute to the formation of the large difference in hydrogen ion concentration between the thylakoid space and the stroma?

-Transport of protons into the thylakoid space as Pq transfers electrons to the cytochrome complex -Protons from the splitting of water remain in the thylakoid space -removal of hydrogen ions in the stroma during the reduction of NADP+

pigment 700 is associated with photosystem...

1

pigment 680 is associated with photosystem...

2

How many turns of the Calvin cycle are required to produce one molecule of glucose?

6

in phase two of calvin cycle 6NADP converts to

6NADP plus phosphate group

thylakoids

A flattened membrane sac inside the chloroplast, used to convert light energy to chemical energy.

action spectrum

A graph that depicts the relative effectiveness of different wavelengths of radiation in driving a particular process.

chlorophyll

A green pigment located within the chloroplasts.

mesophyll cells

A loosely arranged photosynthetic cell located between the bundle sheath and the leaf surface.

photorespiration

A metabolic pathway that consumes oxygen, releases carbon dioxide, generates no ATP, and decreases photosynthetic output; generally occurs on hot dry bright days when stomata close and the oxygen concentration in the leaf exceeds that of carbon dioxide.

stomata

A microscopic pore that allows gas exchange between the environment and the interior of the plant.

C4 plants

A plant that replaces the Calvin cycle for the initial steps that incorporate Co2 into a four carbon compound, the end product of which supplies CO2 for the Calvin cycle

CAM plants

A plant that uses crassulacean acid metabolism, an adaptation for photosynthesis in arid conditions. Carbon dioxide entering open stomata during the night is converted into organic acids, which release CO2 for the Calvin cycle during the day, when stomata are closed.

C3 plants

A plant that uses the Calvin cycle for the initial steps that incorporate CO2 into organic material, forming a three carbon compound as the first stable intermediate.

bundle sheath cells

A protective covering around a leaf vein, consisting of one or more cell layers, usually parenchyma.

photons

A quantum or discrete amount of light energy

noncyclic electron flow

A route of electron flow during the light reactions of photosynthesis that involves both photosystems and produces ATP, NADPH, and oxygen. The net electron flow is from water to NADP+

cyclic electron flow

A route of electron flow during the light reactions of photosynthesis that involves only photosystem I and that produces ATP but not NADPH.

primary electron acceptor

A specialized molecule sharing the reaction center with a pair of reaction center chlorophyll a molecules; it accepts an electron from one of these two chlorophylls

chlorphyll a

A type of blue green photosynthetic pigment that participates directly in light reactions, which convert solar energy to chemical energy.

crassulacean acid metabolism (CAM)

A type of metabolism in which carbon dioxide is taken in at night an incorporated into a variety of organic acids.

chlorophyll b

A type of yellow green accessory photosynthetic pigment that transfers energy to chlorophyll a.

in phase three of calvin cycle ATP converts to

ADP

Chloroplasts can make carbohydrate in the dark if provided with

ATP, NADPH, and CO2

Noncyclic electron flow along with chemiosmosis in the chloroplast results in the production of

ATP, NADPH, and O2

carotenoids

An accessory pigment, either yellow or orange, in the chloroplasts of plants.

PEP carboxylase

An enzyme that adds carbon dioxide to phosphoenolpyruvate to form oxaloacetate

spectrophotometer

An instrument that measures the proportions of light of different wavelengths absorbed and transmitted by a pigment solution.

heterotrophs

An organism that obtains organic food molecules by eating other organisms

autotrophs

An organism that obtains organic food molecules without eating other organisms

Which photon color has more energy: orange (620 nm) or blue (480 nm)

Blue: shorter wavelength = more energy

The photosynthetic process used by some plants to survive in a hot dry climate, like the desert

C4 photosynthesis

what enters the calvin cycle?

CO2

Photosynthesis is a redox process in which

CO2 is reduced and water is oxidized

reaction center

Complex of proteins associate with two special chlorophyll a molecules and a primary electron acceptor. Located centrally in a photosystem, this complex triggers the light reactions of photosynthesis. Excited by light energy, one of the chlorophylls donates an electron to the primary electron acceptor, which passes an electron to an electron transport chain.

light harvesting complex

Complex of proteins associated with pigment molecules that captures light energy and transfers it to reaction center pigments in a photosystem.

Why is neither oxygen nor NADPH generated by cyclic electron flow?

Electrons from P680 aren't passed to P700 and without them, water is not split, meaning NADPH cannot form from NADP+.

output of calvin cycle is

G3P or glucose

photosystem

Light capturing unit located in the thylakoid membrane of the chloroplast,

What are the final electron acceptors for the electron transport chains in the light reactions of photosynthesis in cellular respiration?

NADP+ in the light reactions and O2 in the respiration

The calvin cycle requires what inputs

NADPH,ATP,CO2

How does cyclic electron flow differ from noncyclic flow?

No NADPH or O2 is produced in the cyclic electron flow

photosystem I

One of the two light capturing units in a chloroplast thylakoid membrane; it has two molecules of P700 chlorophyll a at its reaction center.

photosystem II

One of two light capturing units in a chloroplasts thylakoid membrane; its has two molecules of P680 chlorophyll a at its reaction center.

is the main difference between cyclic and noncyclic photophosphorylation?

Only photosystem I is used during the noncyclic process

rubisco

Ribulose carboxylase, the enzyme that catalyzes the first step of the Calvin cycle (the addition of CO2 to Ribulose biphosphate)

glyceraldehyde 3 phosphate

The carbohydrate produced directly from the Calvin cycle.

photosynthesis

The conversion of light energy to chemical energy that is stored in glucose or other organic commpounds

wavelength

The distance between crests of waves, such as those of the electromagnetic spectrum.

electromagnetic spectrum

The entire spectrum or radiation ranging in wavelength from less than a nanometer to more than a kilometer.

stroma

The fluid of the chloroplast surrounding the thylakoid membrane; involved in the synthesis of organic molecules from carbon dioxide to water.

carbon fixation

The incorporation of carbon from CO2 into an organic compound by an autotrophic organism.

visible light

The portion of the electromagnetic spectrum detected as various colors by the human eyes,

photophosphorylation

The process of generating ATP from ADP

absorption spectrum

The range of a pigment's ability to absorb various wavelengths of light.

light reactions

The steps in photosynthesis that occur on the thylakoid membranes of the chloroplasts and that convert solar energy to the chemical energy of ATP and NADPH, evolving oxygen in the process.

Accessory pigments within chloroplasts are responsible for

absorbing photons of different wavelengths of light and passing that energy to P680 or P700

What does rubisco do?

adds CO2 to RuBP in the carbon fixation stage

NADP+

an acceptor that temporarily stores energized electrons produced during the light reactions.

what is the source of the carbon in sugar produced during photosynthesis?

carbon dioxide

first phase of calvin cycle

carbon fixation

In the light dependent reactions, when light strikes the pigments (P700 or P680) what is the immediate result?

excited electrons are passed to electron acceptors

CAM plants avoid photorespiration by

fixing CO2 into organic acids during the night; these acids then release CO2 during the day

Blue light has more energy than red light, therefore blue light

has a shorter wavelength than red light

A difference between electron transport in photosynthesis and respiration is that in photosynthesis

light provides the energy to push electrons to the top of the electron chain, rather than energy from the oxidization of food molecules

Oxidization of NADP+

neither respiration nor photosynthesis

In green plants, most of the ATP for synthesis of proteins, cytoplasmic streaming, and other cellular activities comes directly from

oxidative phosphorylation

Electrons that flow through the two photosystems have their highest potential energy in

photoexcited P700

Reduction of CO2

photosynthesis

second phase of calvin cycle

reduction

third phase of calvin cycle

regeneration of starting molecule

Oxidative phosphorylation

respiration

Reduction of NAD+

respiration

Reduction of oxygen

respiration

Chemiosmotic synthesis occurs during

respiration and photosynthesis

Carbon fixation is catalyzed by what enzyme?

rubisco

not a produce of the light dependent reaction?

sugar

In C4 plants, the Calvin cycle

takes place in the bundle sheath cells

A spectrophotometer can be used to measure

the absorption spectrum of a substance

Where does the Calvin cycle take place in C4 plants?

the bundle sheath

what occurs in the stroma

the calvin cycle

In the calvin cycle, more ATP than NADPH is used, how is this difference made up?

the cyclic pathway creates more ATP

Light reactions occur in

the grana

Calvin cycle

the process of atmospheric CO2 fixation and the reduction of the fixed carbon into carbohydrate.

mesophyll

the soft tissue within a leaf

the Calvin cycle occurs in

the stroma

Electron transport chain occurs in

the thylakoid membrane

The splitting of water occurs in

the thylakoid space

In the chemiosmotic synthesis of ATP in the chloroplast, the hydrogen ion diffuses through the ATP synthase from

the thylakoid space into the stroma

Six molecules of G3P formed in the Calvin cycle are used to produce

three molecules of RuBP and one G3P

What portion of illuminated plant cell would you expect to have the lowest pH?

thylakoid space

NADPH and ATP from the light reactions are both needed

to reduce 3 phosphoglycerate to G3P

The chlorophyll known as P680 has its electron "Holes" filled by electrons from

water

The oxygen produced in photosynthesis comes from what molecule?

water