Crop Phys. Exam 1

PEPcase

Primary molecule used to distribute photoassimilates from leaves to other parts of the plant

Decrease in photosynthesis primarily because damage to PS2 outpaces plant's ability to repair it

Located in chloroplast membranes and chromoplasts, hydrophobic

200-3000nm

Use in movement of electrons in the electron transport chain, from b6f protein to P700 reaction center in PS1

Carboxylation, reduction, regeneration

Amount of incident energy per unit time per unit area

Ion concentration difference and electric potential differences across membranes are sources of free energy that can be utilized by the cell

Ratio of total upper leaf surface area to ground area

Following absorption of light by a leaf pigment, the energy can be transferred to another pigment molecule in the light harvesting complex by this mechanism of energy transfer

Amount of biomass produced by a crop per unit of intercepted solar radiation

porphyrin head+phytol tail, located in chloroplast membranes, hydrophoic

Catalyzes conversion of G3PA to dihydroacetone phosphate

Uptake of O2, release of CO2 in the presence of light

1. PEPcase reacts with C cased molecules, typically bicarbonate

Asperate in, to oxaloacetate, to malate, to pyruvate, leaves as alanine, decarboxylation in mitochonrion

Spectral light composition, spectral energy distribution

Lost as heat, lost as energy (fluorescence), passes to different chlorophyll (fluorescence resonance energy transfer), photochemistry

Fate of light in plants

5-carbon Ribulose Bisphosphate is regenerated from 3 carbon glyceraldehyde-3-phosphate molecules

ATP required in this step of Calvin Cycle

Maximize light interception

Approximate proportions of light associated with the 3 fates

Light is perpendicular to leaf lamina

PAR

CAM

Agave, Orchids, Pineapple

Thick cuticle, low surface to volume ratios, large vacuoles, reduced size & frequency of stomatal openings

The point where CO2 assimilated equals the amount of CO2 taken in

Turning light energy into chemical energy for photosynthesis

Dissipates heat

Plants reduce photosynthesis rates because of excess light/solar radiation. This prevents damage because the plant isn't able to repair quickly enough

Wheat, Soybean

Location of starch synthesis in chloroplast

Reduces reaction between Rubisco and O2, limiting photorespiration

Main storage of carbohydrates in plants, complex polysaccharide composed of two entities (amylase/amylopectin)

DHAP and GA3P

Phosphorylates fructose 6-phosphate

Minimize light interception

Function of leaf inclination angle, leaf grouping, solar angle

PEP CK

Enzyme that allows for C4 to be affective

Inhibitor of two chloroplast enzymes

Provides info about amount of light energy taken up or absorbed by a molecule as a function of the wavelength of light

Corn, Milo

GA3P

PPFD

Initial electron donor in photosynthetic light reactions

Contributes to radiation balance of plants

3-PGA

3-PGA molecule is reduced to GA3P

ATP and NADPH required in this step of Calvin Cycle

Specialized structure of C4 plants, Mesophyll rings around bundle sheath cells, helps concentrate CO2 to limit

Used for starch synthesis, or pumped into cytosol to be made into sucrose

Embedded in the lipid bilayer; Function: ion channels, pumps, include main protein complexes in light reactions

Biological response to the length and timing of day and night

and water interface reflect and refract light

Malate into bundle sheath cells, leaves as pyruvate, decarboxylation in chloroplasts

Enzyme that catalyzes the reaction leading to the first stable carbon compound in C4 plants

Energy contained in a photon

Influence and roles of light on plant development

Regulation of amount of ATP to NADPH produced based on how much of each material is needed (cyclic and non-cyclic)

Ability for a plant to perform photosynthesis or assimilate CO2

Bound to membrane surface via lipid molecules; Function: Phosphorylation (kinases), messenger cascades (G proteins)

6-carbon input molecule split into two 3-carbon molecules that are stable

Photons are reflected by chlorophyll

DHAP

Asperate in, to oxaloacetate, to phospheno-pyruvate, carboxylation in cytosol

Starch that accumulates for use during night

Bound to membrane surface by noncovalent bonds; Function: plasma membrane and cytoskeleton interactions

Detergent resistant aggregates of lipids and proteins; Function: facilitate interactions of specific membrane proteins involved in cell signaling

Enzyme that catalyzes the reaction leading to the first stable carbon compound in C3 plants