In recent molecular genetic studies, genes associated with the neurotransmitter Dopamine have been linked to ADHD.
ADHD stands for Attention Deficit Hyperactivity Disorder. People with ADHD have a hard time focusing on tasks. Scientists have found that the low levels of dopamine in the brain are associated with the symptoms of ADHD. It is because the neurons in the brain have a high amount of protein called the dopamine transporters. These proteins block the dopamine from passing between the neurons. This decreases the effect of dopamine.
Sinks of carbon dioxide can be farms grasslands or forest
Temperature, viscosity, and amount of dissolved gases
The correct answer is: A. The hydrophilic head groups of the lipid molecules are exposed to the outside of the cell and the cytoplasm, which is a water-like environment. The hydrophobic tails form an oily layer inside the membrane that keeps water out of the cell.
Plasma membrane of the cell is arranged in a bilayer of phospholipids. Phospholipids are amphipathic molecules which means that they have both hydrophilic and hydrophobic regions. The hydrophilic heads of phospholipids that are faced outward and hydrophobic layer located in the interior of the bilayer together make a good barrier between the interior and exterior of the cell, so the water and other polar or charged substances cannot easily cross the hydrophobic core of the membrane.
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