Table of Contents
What are the products of PSII?
Photosystem II obtains replacement electrons from water molecules, resulting in their split into hydrogen ions (H+) and oxygen atoms. The oxygen atoms combine to form molecular oxygen (O2), which is released into the atmosphere.
Which of the following herbicides inhibit photosystem 1?
They divert electrons from the normal electron transport sequence necessary in Photosystem I. This in turn inhibits photosynthesis. The membrane disruption occurs as a result of secondary responses. Herbicides that inhibit Photosystem I are represented by only one family, the bipyridyliums.
Which herbicide is photosynthesis inhibitor?
The photosynthesis inhibitors include these herbicide families: Triazine. Triazinone. Phenylurea.
What is the end product of photosystem I?
ATP is the product of photosystem I.
What are examples of herbicides?
Herbicide List
- Metribuzin, Dacthal, Sethoxydim.
- Carfentrazone, Pendimethalin.
- Halosulfuran-methyl, Bensulide.
- Trifluralin, Napropamide.
How do PSII inhibitors work?
Blocking electron transport in PSII systems promotes the formation of highly reactive molecules that initiate a chain of reactions causing lipid and protein membrane destruction that results in membrane leakage allowing cells and cell organelles to dry and rapidly disintegrate.
How does Atrazine block photosynthesis?
Atrazine inhibits photosynthesis by competitively associating with the plastoquinone B (QB) binding site of the D1 subunit of PSII, and therefore blocks chloroplast electron flow from plastoquinone A to QB, greatly reducing the production of ATP, nicotinamide adenine dinucleotide phosphate (NADPH), and CO2 fixation ( …
How do herbicides affect photosystem II?
In general, these herbicides inhibit photosynthesis by binding to D1 proteins of the photosystem II complex in chloroplast thylakoid membranes. Herbicide binding at this protein blocks electron transport and stops CO2 fixation and production of energy needed for plant growth.
Where is PSII located?
the thylakoid membrane
PSII is located at the inner surface of the thylakoid membrane, and contains chlorophyll b; chlorophyll a (forms a-660, a-670, a-680, a-695, a-700), phycobillins, and xanthophylls; and a Chl a-P680 form is the active reaction center.
What is PSII and PSI?
Photosystem I (PSI) and Photosystem II (PSII) harvest light energy to drive photosynthesis. In plants these photosystems are composed of a core complex and a peripheral antenna system.
What brands contain atrazine?
Atrazine products registered for use in Minnesota – 2019
| Product Name | Product Name | Product Name |
|---|---|---|
| ATRAZINE 90 WDG | FULTIME | STALWART XTRA |
| ATRAZINE DF (ADAMA) | FULTIME NXT | STALWART XTRA LITE |
| BICEP II MAGNUM | HARNESS XTRA | TENKOZ ATRAZINE 4L |
| BICEP II MAGNUM FC | HARNESS XTRA 5.6L | TENKOZ ATRAZINE 90DF |
What are photosynthesis inhibitors?
The photosynthesis inhibitors include these herbicide families: Photosynthesis inhibitors disrupt the photosynthetic (food producing) process in susceptible plants by binding to specific sites within the photosystem II complex in plant chloroplasts.
How do herbicides interact with photosystem II?
It has been estimated that perhaps as many as half of available herbicides have a mode of action that involves interaction with a few components in the electron transfer chain of Photosystem II. Remember that transfer of electrons from Photosystem II to Photosystem I is essential for the production of photosynthetic energy. A key step in this
How does the molecular structure affect the effectiveness of a herbicide?
Since the mode of action involves competition for a binding site within a membrane environment, the effectiveness of the herbicide will be greatly affected by small changes in its structure. Thus, small modifications in the molecular structure of a herbicide may cause differential sensitivity in different species of plants.