RNA- Definition, Properties, Structure, Composition, Types, Functions

RNA- Definition, Properties, Structure, Composition, Types, Functions

RNA Definition RNA (Ribonucleic acid) is a single-stranded nucleic acid molecule and made up of ribonucleotides. A ribose nucleotide in the chain of RNA consists of a ribose sugar, phosphate group, and a base. In each ribose sugar, one of the four bases is added: Adenine (A), Guanine (G), Cytosine (C), and Uracil (U). The base is attached to a ribose sugar with the help of a phosphodiester bond. As RNA comprises many ribose nucleotides, the length of the chains … Read more

DNA- Definition, Properties, Structure, Composition, Types, Functions

DNA- Definition, Properties, Structure, Composition, Types, Functions

DNA (Deoxyribonucleic acid) Definition Deoxyribonucleic acid (DNA) is the heredity material found in humans and all living organisms. It is a double-stranded molecule and has a unique twisted helical structure. DNA is made up of nucleotides, each nucleotide has three components: a backbone made up of a sugar (Deoxyribose) and phosphate group and a nitrogen-containing base attached to the sugar. Each strand has many nucleotides or says numerous sugar, a phosphate group, and nitrogenous bases. These nitrogenous bases are complementary … Read more

Cell Organelles (Plant, Animal)- Structure, Functions, Diagrams

Cell Organelles (Plant and Animal)- Structure, Functions, Diagrams

Cell Organelles Definition The cell is the basic unit of organization or structure of living matter bound by the semipermeable membrane and is capable of self-replicating in a medium free of other living systems. Cell organelle is the cellular component that can be both membranous and non-membranous present within a cell having distinct structures and functions. Cell Membrane Cell membrane or plasma membrane or plasmalemma is the thin and delicate layer that encloses the cell by defining the boundaries and … Read more

Cilia- Definition, Structure, Ultrastructure, Functions

Cilia- Definition, Structure, Ultrastructure, Functions

What are Cilia? The word cilia is derived from the Latin word cili which means eyelash. In the Latin word, Flagella means little whip. They are microscopic which can’t be seen with naked eyes. They have the contractile property and are filamentous processes of the cytoplasm. Food currents are created by the cilia. They act as sensory organs. They perform different mechanical functions. Cilia and flagella though it looks similar, they vary in the various aspects i.e number, size, functions. … Read more

Microtubules- Definition, Structure, Composition, Functions


What are Microtubules? The cytoskeleton of the eukaryotic cell is made of proteins that give shape to it. The three types of protein that help in the organization of the cell are microtubules, intermediate filaments, and microfilaments. This cytoskeleton is absent in the bacteria. Tubulin is present in the microtubules. In 1953, Robertis and Franchi observed the microtubules in the axoplasm of the myelinated nerve fibers. It was called the neurotubules. In 1963, Ledbetter and Porter described the microtubules of … Read more

Centrioles and Basal Bodies- Definition, Structure, Functions


What are Centrioles and Basal Bodies? In some eukaryotic cells, near the nucleus, there is the presence of two cylindrical structures. They are rod-shaped and microtubular. They are known as the centrioles. A limiting membrane is absent in it. DNA or RNA is also absent in it. It also forms the spindle of microtubules. It is also found to be arranged beneath the plasma membrane for the formation of cilia or flagella. The basal body is the centriole having the … Read more

Lysosomes- Definition, Structure, Enzymes, Types, Functions


What are Lysosomes? The name Lysosome is derived from the Greek word where “lyso” means digestive and “soma” means body. Lysosomes are membrane-bound vesicle which is tiny in the structure. Lysosomes are involved in intracellular digestion. Different kinds of hydrolytic enzymes are present in the lysosome. Under acidic conditions, these enzymes are found to be active. The lumen of the lysosome is acidic which is around pH 5. This condition is maintained in the membrane by the ATP-driven proton pump. … Read more

Ribosome- Definition, Types, Structure, Composition, Functions


What is Ribosome? The ribosome is a large complex that is made from dozens of small proteins. These small proteins are ribosomal proteins. It consists of many several RNA molecules which are called ribosomal RNAs (rRNAs). The word ribosome is made up of ribo+somes. “Ribo” stands for ribonucleic acid. In the Greek word, ‘soma’ refers to the body. From it, the “somes” is derived. Occurrence of ribosomes: in the prokaryotic cells:  freely in the cytoplasm in the eukaryotic cells: freely … Read more

Rough Endoplasmic Reticulum (RER)- Definition, Structure, Functions

Rough Endoplasmic Reticulum (RER)

What is Rough Endoplasmic Reticulum (RER)? The endoplasmic reticulum (ER) which consists of ribosomes on its surface is known as the rough endoplasmic reticulum. So it is also called the granular endoplasmic reticulum. Translocon is the binding site of the ribosome on the rough endoplasmic reticulum. These ribosomes look like studs and they can distinguish the organelle from the smooth sections of the ER. Proteins are synthesized from amino acids. It is with the aid ribosome. Ribosomes consist of four … Read more

Testing for Biological Molecules

Testing for Biological Molecules

Benedict’s test for reducing sugars Definition Benedict’s test is a biochemical test performed to distinguish reducing sugars (monosaccharides and some disaccharides) from non-reducing sugars. Objectives To detect the presence of simple carbohydrates in a solution. To distinguish between reducing and non-reducing sugars. Principle The carbohydrates having a free or potentially free, aldehyde or ketone group can act as a reducing agent. In order to detect the reducing agent, Benedict’s reagent is used. It appears deep blue in color and consists … Read more