Answer:
Cellular membranes or plasma membranes has many functions. Some of these include regulation of cellular transport, and responding to cellular signals or hormones.
<h2>Cellular Transport</h2>
The plasma membrane is made up of the <u>phospholipid bilayer with embedded transmembrane proteins</u>. This makes the cell membrane <u>semi-permeable</u>. Movements of substances depend on the composition of the molecules e.g. glucose and amino acids, as needed by the pancreatic cells. These are larger and uncharged molecules and can't pass freely through the membrane so they utilize the transmembrane proteins via attaching to carrier proteins. This is called <em>passive transport</em>. On the other hand, in <em>active transport</em>, <u>ATP is used</u> to transfer molecules, like Hydrogen, from a low to high electrochemical gradient.
Other kinds of cellular transport are:
- Osmosis and diffusion
- Endocytosis
- Exocytosis
<h2>Cellular Signalling</h2>
The cell membrane is able to signal other neighboring cells by utilizing complex proteins. These proteins may take form as receptors or markers.
<h3>Membrane Receptors</h3>
They act as receivers of extracellular signals and spark intracellular processes. These receive signals from hormones, growth factors, etc.
<h3>
Membrane Markers </h3>
These allow the cells to identify each other and respond if this cell is needs further development as in organ development, or a foreign body to the system.
Proteins are unbranched polymers constructed from 22 standard α-amino acids.
The protein show four levels of structural organisation; the primary structure, secondary structure, tertiary structure and quaternary structure.
The structure of proteins are stabilized by peptide bonds between the amino acid and hydrogen bond between the peptide chainds.
The primary structure of a protein is determined by the sequence of amino acids, but secondary and tertiary structures of protein define their natural or native conformation.
The solubility of protein varies according to the pH, ionic strength, nature of solvent, temperature etc.
Proteins can be classified as simple proteins or conjugated proteins on the basis of their composition.
The proteins can also be classified as fibrous proteins or globular proteins on the basis of their shape.
Proteins play a major part in body structure and function as most of the molecules like antibodies, immunoglobulins, hemoglobin, myoglobin ,most of the enzymes are proteins.
So proteins are also called building blocks of the body.
Answer:
Emile Durkheim argued that society was like a human body (the organic analogy). Society was made up of various institutions that acted like the organs of the body: they all needed to be functioning properly for the body to function.
Explanation: