Answer: Mercury has been well known as an environmental pollutant for several decades. As early as the 1950's it was established that emissions of mercury to the environment could have serious effects on human health. These early studies demonstrated that fish and other wildlife from various ecosystems commonly attain mercury levels of toxicological concern when directly affected by mercury-containing emissions from human-related activities. Human health concerns arise when fish and wildlife from these ecosystems are consumed by humans.
During the past decade, a new trend has emerged with regard to mercury pollution. Investigations initiated in the late 1980's in the northern-tier states of the U.S., Canada, and Nordic countries found that fish, mainly from nutrient-poor lakes and often in very remote areas, commonly have high levels of mercury. More recent fish sampling surveys in other regions of the U.S. have shown widespread mercury contamination in streams, wet-lands, reservoirs, and lakes. To date, 33 states have issued fish consumption advisories because of mercury contamination.
These continental to global scale occurrences of mercury contamination cannot be linked to individual emissions of mercury, but instead are due to widespread air pollution. When scientists measure mercury levels in air and surface water, however, the observed levels are extraordinarily low.
Explanation:
Which of what? could you be more clear?
The mitochondria is the powerhouse of the cell!
Dependent and independent variables are variables in mathematical modeling, statistical modeling and experimental sciences
Answer:G protein action
Explanation:
Signal transduction through protein action is through G protein coupled receptors (GPCR). Binding of different types of signal molecules to G protein couple receptors is a general mechanism of signal transduction.
G proteins act as an intermediary to a stimulation of a receptor. When an extracellular messenger, the hormone (H) combines with the specific receptor (R) on the plasma membrane. The H-R complex activates the regulatory components of G proteins. The G-protein inturn will interact with the effect proteins which may be enzymes or ion channel proteins, which result in the desired effect.
