Which of the following are not polymeric?

Nucleic acids, Polysaccharides and Proteins are polymers and lipids are usually not polymers.

To understand this, let us analyze each option:

Nucleic Acids: Nucleic acids, such as DNA and RNA, are polymeric molecules because they are made up of repeating monomeric units called nucleotides. Each nucleotide consists of a sugar, a phosphate group, and a nitrogenous base, and they are linked together by phosphodiester bonds. Hence, nucleic acids are polymeric.

Proteins: Proteins are also polymeric molecules as they are formed from repeating units of amino acids, which are joined together by peptide bonds. These chains of amino acids fold into specific structures to perform various biological functions. Therefore, proteins are polymeric in nature.

Polysaccharides: Polysaccharides, such as starch, cellulose, and glycogen, are polymeric carbohydrates composed of long chains of monosaccharide units (like glucose) linked together by glycosidic bonds. They serve as energy storage or structural components in living organisms, making them polymeric.

Lipids: Lipids, on the other hand, are not polymeric. They are made up of smaller non-repeating units, such as glycerol and fatty acids, which are linked through ester bonds. Unlike polymers, lipids do not have a chain-like structure with repeating monomeric units. Instead, they are diverse in structure and function, primarily serving as components of cell membranes and as energy storage molecules. Thus, lipids are not considered polymers.

Summary:
Polymeric: Nucleic acids, proteins, polysaccharides.
Not polymeric: Lipids.
Lipids are distinct from the other biomolecules because their structure does not consist of repeating monomer units, which is a defining characteristic of polymers..