what is the definition for..(look in detail)?

Question

1.non-polar tails
2.polar heads
3.receptor-mediated endocytosis
4.embedded proteins

Answer 1

Non-polar tails and polar heads refer to detergents (like SDS, ingredient in most of your household soaps). Non-polar tails are long carbon-hydrogen chains that are hydrophobic ("fear water" meaning do not combine with water). Polar heads are at one end of the non-polar tail, much smaller by comparison and are hydrophilic ("love water" meaning they do combine with water). This is great for soaps since the non-polar tail bind to grease/oil and can be washed away by water. This is also a huge property of cell membrane structure (phospholipid bilayer).

Receptor-mediated endocytosis forms endosomes (a vesicle of proteins). Cells bring proteins (and/or other ligands) into itself via receptors (it kind of looks like pinching a piece of the cell membrane inward and then "floating" in the cytoplasm).

Embedded proteins are stuck in the cell membrane. These are usually receptors of some kind which can be involved in endocytosis or intercellular communication.

Answer 2

Polar heads and non-polar tails in a biology question generally refer to the phospholipids which make up the cell membrane. A double layer of these form such that the polar heads are on the outside, with the non-polar tails of each sandwiched in the middle. This makes the membrane both polar and non-polar and makes it more difficult for molecules to enter the cell uncontrolled.

Answer 3

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