Answer:
The cell membrane (also called the phospholipid bilayer or the plasma membrane) is one of the most important structures a cell has. If you think of the cell as a really popular nightclub, the membrane is the bouncer. It decides what enters and exits the cell.
Explanation:
Fossil fuels are important energy sources for our every day activities.
Formation of fossil fuels
Fossil fuels forms from the accumulation and burial of organisms in a basin of deposition. Instead of the organisms decaying, they preserve their carbon content. To be worthy of becoming fossil fuels, organisms must be buried in an environment where there is little to no oxygen to fast-track decomposition of the buried organic matter. Increase in temperature and pressure causes the organic matter to transform into fossil fuels.
How are they obtained
First, different fossil fuels have their extraction techniques because they occur in different physical state of matter.
For the solids e.g coal: exploration is carried out first and if a prospect is delineated, mining engineers design the best way to extract the coal from nature. Coal is usually found laid in sedimentary beds in nature. Top layers of sediments can be removed to extract the coal.
For fluids such as crude oil and natural gas, after a prospect is identified, a rig is usually constructed to extract the fluid and gas. The natural pressure allows for the fluids the rise within the drill used in extraction.
How are they used
Coal and gas are used to power electrical generating plants. They are used to heat steams which drives turbines and produce electricity.
Natural gas is used as a domestic fuel for cooking and so also coal.
When crude is processed a lot of product is obtained. Gasoline is used to power most internal combustion engines. Some chemicals useful for manufacturing plastics, drugs e.t.c are also derived from the processed crude.
Learn more:
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Answer:
Placebo, Is used to describe a substance given in clinical trial that does not contain the drug.
Explanation:
- Clinical trials are done to evaluate the effectiveness of a drug in treating a particular medical symptom or disease.
- In such case a placebo is used as a control in the experiment.
- A placebo contains all the components as the medicine except for the drug that is being tested.
- A placebo is given to one group of patients having the symptoms for which the drug is tested while another group of patients with same symptoms are given the drug.
- If the group that was given the drug show symptoms of cure while the group that was given placebo does not show changes. Then the drug is said to be effective.
Abundant amount of amino acids made up a polypeptide