Sulfur<span> is an important structural atom in most </span>proteins<span> as </span>sulfur amino acids. It defines its structure. <span>The </span>sulfur<span>-containing </span>amino acids<span>, </span>can<span> be converted into each other but neither </span>can<span>be synthesized in humans. Hope this answers the question. Have a nice day.</span>
On the planet earth. They exist in what we call the "world", which holds all seen life.
Answer:
Absorption
Thousands of pores on the surface of the skin can absorb vitamins, acids, water and oxygen in order to provide moisture and nourishment to our skin.
Excretion
The skin is the body’s largest waste removal system. Toxins are released through the sweat glands and pores.
Secretion
The skin secretes sebum, a mixture of oils that keeps the skin soft and supple. The layer of sebum on the outermost layer of the skin is known as the acid mantle. When intact the acid mantle has a PH that ranges from 4.5-5.5. The acid mantle is acidic in nature to protect the skin from outside invasion.
Regulation
The skin regulates the body’s temperature by sweating; when water from sweat on the skin evaporates it gives off heat and cools the body. The body’s temperature increases or by shivering or getting goosebumps when the body is cold. The contraction of muscles releases energy that warms the body.
Sensation
The skin contains millions of nerve endings that transport stimuli. These nerve endings allow humans to detect sensation such as heat, cold, pain and pressure.
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Sources: Salon fundamentals Esthetics Textbook: The Integumentary System