ANon-Nutritive chemical
BDerived from sea weeds
CUsed to prepare solid media
DAll are true
Answer:
D. All are true
Read Explanation:
Source and Extraction
Agar, also known as agar-agar, is a phycocolloid, a gelatinous substance extracted from the cell walls of specific species of red algae (Rhodophyta).
Primary commercial sources include Gelidium and Gracilaria species.
The process involves boiling the seaweed, filtering out the debris, and then cooling and dehydrating the resulting gel.
Chemical Composition
It is a mixture of two polysaccharides: agarose (the gelling component) and agaropectin (a mixture of smaller molecules).
Chemically, it is a polymer made up of subunits of the sugar galactose.
Key Applications
Microbiology: It is the standard solidifying agent used in culture media (like Nutrient Agar) to grow bacteria, fungi, and other microorganisms in laboratories because it is not easily degraded by most bacteria.
Food Industry: Used as a vegetarian alternative to gelatin, a thickening agent, a gelling agent for jams, jellies, ice creams, and vegan desserts.
Molecular Biology: Agarose gel electrophoresis is a critical technique used to separate DNA, RNA, and protein molecules based on their size.
Pharmaceuticals: Utilized as a laxative, a suspending agent, and in the preparation of capsules and tablets.