Answer:
Phospholipid bilayer.
Explanation:
The plasma membrane (also known as the cell membrane or cytoplasmic membrane) is defined as a biological membrane that separates the interiors of a cell from its external environment.
The plasma membrane has a function that protects the cell from its external environment, mediates cellular transport, and transmits cellular signals.
It is composed of a lipids bilayer (phospholipids and cholesterol), (phospholipid is a lipid made of glycerol, two fatty acid tails, and a phosphate-linked head group) with embedded proteins, the plasma membrane is selectively permeable to ions and organic molecules which hence, regulates the movement of substances in and out of cells. Plasma membranes is very flexible in order to allow cells change form example, red blood cells change shape as they pass through narrow capillaries.
Answer:
Cells are the basic structure and unit of life. There are prokaryotic and eukaryotic cells. Prokaryotic cells are very basic, and have no nucleus, few organelles, and are ususally bacteria. Eukaryotic cells are more complex and have nuclei, are larger compared to prokaryotic cells, more organelles, and have emembrane bound organelles. There are plant and animals cells, each have certain organelles that other don't. For example, plant cells have large vacuoles and a cell wall; animal cells have centrioles. Cells are important because they provide strucure for the body, and take in nutrients from food and carry out many important functions, such as protein synthesis, respiration, growth and development, and more. Billions of cells make up a complex organism's body, while a single cell can make up an entire organisms, and carry out all of the needed functions. That's a quick summary of what cells are, and some of the things that they do that make them so important
Explanation:
Answer:
Actin filaments return to their original positions (does not occur in muscle contraction, according to the sliding filament model).
Explanation:
