What happens during photosystem I?

What happens during photosystem I?

The light reaction occurs in two photosystems (units of chlorophyll molecules). Photosystem I obtains replacement electrons from the electron transport chain. ATP provides the energy and NADPH provides the hydrogen atoms needed to drive the subsequent photosynthetic dark reaction, or Calvin cycle.

What are the functions of photosystem I and photosystem II in plants?

Photosystem I produces NADPH, which is similar in function to the NADH and FADH2 produced by the citric acid cycle. NADPH is an electron carrier that can donate electrons to other compounds and thus reduce them. Photosystem II produces a proton gradient that drives the synthesis of ATP.

How long does atrazine stay in soil?

Atrazine does not bind well to soil and can easily move in it. It has an average half-life in soil of around 60-75 days.

Why is atrazine banned in Europe?

Abstract. Atrazine is a common agricultural herbicide with endocrine disruptor activity. Although the U.S. Environmental Protection Agency (EPA) approved its continued use in October 2003, that same month the European Union (EU) announced a ban of atrazine because of ubiquitous and unpreventable water contamination.

Is atrazine still used?

The agency expects to complete that work in 2021. In anticipation of future restrictions related to endangered species risks, pesticide manufacturer Syngenta is canceling use of atrazine in Hawaii, Puerto Rico, and US territories, as well as all uses of the herbicide on conifers and roadsides.

When was atrazine invented?

1958

What crop is atrazine usually applied to?

Atrazine is an herbicide widely used for control of broadleaf and grassy weeds. It is sprayed on row crops such as corn, sorghum and sugarcane, and in some areas is used on residential lawns. It has also been used on highway and railroad rights-of-way. EPA now restricts how atrazine can be used and applied.