Autotrophs get their energy from the environment, primary producers

Heterotrophs get their energy in the form of organic molecules from the other organisms

Visible light: Light that a human can see

Range from 400-700 nm

When light hits an object, it has 3 fates. 

List these fates

Reflected

Transmitted

Absorbed

• PSII- a large protein complex
• Plastoquinone- a membrane lipid
• cyt b6f complex-a large protein complex
• Plastocyanin- a blue Cu protein
• PSI- a reaction that absorbs light
• ATPase- makes ATP

*Describe electron flow through to the NADP reduction*

Will be on exam

1. Light absorbed by the PSII transfers an electron from the splitting of water to PQ
2. PQ carries 2 electrons and 2 protons, so after it receives 2e- it picks up 2H+ from the stroma
3. PQ carries the e-'s and protons to the lumen side of the membrane where it passes the electrons out to the cyt b6f complex
4. The cyt b6f complex only accepts electrons, so the protons are released into the lumen
5. The cyt b6f complex along with PQ conducts a Q-cycle, doubling the # of H+'s pumped to 4
6. The electrons pass from the cyt b6f complex to plastocyanin
7. Plastocyanin carries the e-'s to PSI
8. At PSI, light is absorbed and transfers the e-'s to ferridoxin
9. Ferridoxin give the electrons to NADP forming NADPH

2 protons are in the lumen as a result of splitting H₂O

4 protons are pumped into the lumen by plastoquinines and the b6f complex

1 proton is consumed in the stroma by formation of NADPH

Explain how the light harvesting complexes function.

What components are functioning?

Energy of the exciton is used to move an electron out of P680 or P700. In PSII this electron goes to plastoquinone, whereas in PSI it goes to ferridoxin

Components: carotenoids, chlorophyll b & a

O₂

ATP

NADH

• Decarboxylation in the bundle sheath cells makes it possible to create high concentrations of CO₂ in the bundle sheath cells, greatly reducing photorespiration
• The Kranz anatomy makes it so that the products of photosynthesis (sucrose) can be rapidly removed, eliminating end-product inhibition of PS

High photosynthesis rates correlate with strong sinks

More sinks, faster photosynthesis

• Breakdown of storage and translocation forms of carbohydrates
• Glycolysis
• Krebs cycle
• Electron Transport Chain

For sucrose, starch, and fructans give the following:

Where they are synthesized, nature of the molecule, storage or translocation

Starch: Synthesized in chloroplasts, sprial structure, storage

Fructans: Synthesized in vacuole, common in plants that grow during cool seasons, storage

Sucrose: Synthesized in the cytoplasm from gluctose and fructose, disaccharide containing glucose and fructose, used for translocation

Pyruvate-goes to mitochondria for Krebs cycle

NADH-goes to the mitochondria and used by ETC

ATP-used to do work in the cell

1) Conversion of pyruvate to acetyl CoA--one CO₂ molecule and one molecule NADH

2) Condensation of acetyl CoA with OAA to form citrate--no energy needed/formed here

3) Regeneration of OAA--7 enzymes produced, NADH, UQH₂, ATP, CO₂'s released

• Matrix NADH dehydrogenase complex-large protein complex
• Ubiquinone-small membrane lipid
• Cytochrome bc₁ complex-medium sized protein complex
• Cytochrome c-small protein in the intermembrane space
• Cytochrome oxidase-large protein complex

intermembrance space

ATP synthesis

Reduced quinone pool can go one of two branched ways

Cytochrome pathway-ATP synthesized

Alternative pathway-Heat

ATP

H₂O

Central metabolism provides carbon skeletons for the synthesis of materials for growth.

As these molecules are removed from central metabolism, respiration increases to replace them. 

Thus a high respiration rate is associated with rapid growth.

ETC stops working

Krebs cycle rapidly stops

Pyruvate turns into acid

Drop in pH and production of an enzyme

Ethanol is produced

Glycolysis can continue

Seed coat--derived from the integuments

An aleurone layer--differentiate from the outermost layer of the endosperm

Variable amounts of endosperm--sometimes a nucellis is present

The embryo

Means of reproduction

Dispersal of the species

Protect the species through bad times

Upper tier gives rise to the SAM, most of the cotyledons

Lower tier gives rise to the shoulder of cotyledons, produces the hypocotyl, root, and proximal initals of RAM

Second cotyledon develops opposite of first

Shoot apical meristem forms

1^st leaf is formed perpendicular to cotyledons, 2^nd formed opposite

Physical protection of the embryo

Barrier to prevent water entry into the dry seed

Barrier to fungal or bacterial invasion

Sometimes designed to help seed dispersal

Seed detaches from the parent plant and dessicates

The integuments harden to form the seed coat

ABA is expressed in the seed to enforce dormancy

ABA

GA

Imbibition--when a quiescent seed comes into the contact with water, membrane systems regain semipermeability

Germination--Metabolism starts, gains carbon skeletons and energy, complete when embryo emerges from seed coat

Surrounds inactive endosperm

GA (?)

-Fixation of CO₂ into 3-phosphoglycerate (carboxylation)

-Reduction of 3-phosphoglycerate to 3-phosphoglyceraldehyde (NADH & ATP)

-Regeneration of RuBP for the cycle to continue (ATP)

• Turned into starch inside of the chloroplast
• Shipped out of the chloroplast and turned into sucrose
• Shipped out of the chloroplast and used in the same cell for respiration

RuBP + O2 rubisco --> 2 molecules of 3-phosphoglycerate

RuBP + O2 rubisco --> 1 molecule of 3-phosphoglycerate

1 molecule of 3-phosphoglycolate

No CO₂ fixed

Something has to be done with the 2-C molecule

CO₂ is released

C3--Rubisco in chloroplasts of mesophyll cells during the day

C4--PEPcase in the chloroplasts of mesophyll cells during the day, then rubisco in chloroplasts of bundle sheath cells during the same day

CAM--PEPcase in the cytosol of mesophyll cells during the night, then rubisco in chloroplasts of mesophyll cells the next day

True fruit-only ovary wall is incorporated into the fruit

Accessory fruit-other floral parts are also incorporated into the fruit, often receptacle becomes part of the fruit

Simple fruits-result from a single flower with one pistil

Aggregate fruits-result from several pistils aggregated in a single flower

Multiple fruits-multiple flowers, inflorescence, with each flower product of a fruit, mature into a single mass

Exocarp

Mesocarp

Endocarp

Along the midvein

Along the union of two carpels

Formation of pores

Berry from an inferior ovary

Results from receptacle fused with the ovary

Cucumbers, squash

Cell division

Cell expansion

Ripening

Increase in ethylene production, then increase in respiration

Burst in respiration provides energy for fruit ripening

(tomato, banana, apple)

Produces bracts and floral meristems at regular intervals in a phyllotaxy

Produces nodes and internodes

Patterns of bifurcation results in different types of inflorescences

Whether or not the inflorescence is determinant or indeterminant

Spike--raceme with flowers without pedicel

Umbel--raceme with short axis and multiple pedicels of equal wavelength from common point

Describe the anatomy of the inflorescences in a capitulum

Head is an indeterminant inflorescence, vertical axis is flattened and inflorescence develops on an expanded receptacle subtended by a cluster of bracts called "involucral bracts"

Sunflowers