Experiment one, because she repeated the experiment several times.
Answer:
Explanation:
It is the lactic acid which makes milk taste sour. Pasteurising milk kills off harmful bacteria and greatly reduces the number of lactobacillus ensuring that milk will last up to three weeks in a fridge. Lactobacillus is a very useful bacterium as the acidic conditions it creates makes a milk protein called casein turn to curd.
Answer:
The correct order of events is:
C) Nicotine binds to the transmembrane protein that normally binds the neurotransmitter acetylcholine.
A) The acetylcholine receptor is an ion channel, and when a ligand binds, the ion channel opens.
B) An influx of ions carries the signal to the reward areas of the brain.
D) The signal causes release of dopamine in the brain, which causes good feelings.
E) Nicotine is quickly eliminated from the body (causing cravings for more cigarettes to produce good feelings).
Explanation:
Nicotine acts on acetyl cholinergic receptors that are located in membranes of the midbrain neurons. Nicotine can activate those receptors or block them more efficiently than acetylcholine. Stimulation of nicotinic receptors leads to an increase in ions flow that reaches the brain and causes dopamine release in the nucleus accumbens through axonal prolongations of the dopaminergic pathway. This response is responsible for the smoker´s recompense sensation.
The dopaminergic pathway is the most important way in the process of nicotine dependence and addiction to the drug.
The immune system<span> recognizes HIV by its antigen shape. But, just when the immune system recognizes one shape, HIV may multiply and change the shape of its antigen. </span><span>HIV can "hide" from the immune system for a long time. </span><span>When HIV infects a cell the </span>virus<span> may make more viruses and infect more cells or lie quietly in a cell for a long time. If HIV doesn't reproduce, the immune system can't find it and destroy it. </span>HIV destroys the immune system. The Immune system consists of Innate Immunity and Humoral Immunity Innate Immunity is Non-specific Immunity, whereas Humoral Immunity is specific Immunity. T-cells produce Cell-Mediated Immunity and B-cells produces Humoral Mediated Immunity. <span>As HIV destroys more and more helper T cells, the immune system begins to break down. </span> Finally the immune system can no longer kill HIV or any other invading germs and a person infected with HIV is diagnosed with AIDS.
