Stem cells refer to such cells that can differentiate into other types of cells and can also divide in self-renewal to produce more of the same type of same cells. The earliest stem cells in the human body are those found in the human embryo. The stem cells inside an embryo will eventually give rise … Read more Stem Cells- Sources, Characteristics, Types, Uses
Passive Transport Plasma membranes must allow certain substances to enter and leave a cell, and prevent some harmful materials from entering and some essential materials from leaving. In other words, plasma membranes are selectively permeable—they allow some substances to pass through, but not others. If they were to lose this selectivity, the cell would no longer … Read more Passive Transport
Membrane Proteins Biological membranes consist of a continuous double layer of lipid molecules in which membrane proteins are embedded. Although the lipid bilayer provides the basic structure of biological membranes, the membrane proteins perform most of the membrane’s specific tasks and therefore give each type of cell membrane its characteristic functional properties. The amounts and … Read more Membrane Proteins
Membrane Lipids Biological membranes consist of a lipid bilayer to which proteins and carbohydrates may be associated or covalently linked. Membrane lipids are lipids involved in forming the structure of biological membranes – both the cell membrane and intracellular membranes – and in membrane function, namely compartmentalization of biological processes. Membrane lipids consist primarily of … Read more Membrane Lipids
Plasmodesmata- Structure and Functions Every living cell in a higher plant is connected to its living neighbours by fine cytoplasmic channels, each of which is called a plasmodesma which passes through the intervening cell walls. They act like tunnels running through the cell wall which allow communication with the other cells in a tissue. The … Read more Plasmodesmata- Structure and Functions
Peroxisomes- Structure and Functions Peroxisomes are small, membrane-enclosed cellular organelles containing oxidative enzymes which are involved in a variety of metabolic reactions, including several aspects of energy metabolism. They are considered as an important type of microbody found in both plants and animal cells. They were identified as organelles by Belgian cytologist Christian de Duve … Read more Peroxisomes- Structure and Functions
Vesicles- Structure, Types, and Functions Cells must be able to move molecules, digest particles, and secrete materials in order to survive. For many cellular functions, vesicles are used. A vesicle is a small, spherical compartment that is separated from the cytosol by at least one lipid bilayer. Many vesicles are made in the Golgi apparatus and the endoplasmic reticulum … Read more Vesicles- Structure, Types, and Functions
Storage Granules- Structure and Functions Storage granules are membrane-bounded vesicles containing condensed materials. They are also known as zymogen granules or condensing vacuoles. Storage granules are an important component of metabolism in many organisms spanning the bacterial, eukaryotes and archaeal domains. These granules are the parts of the cell that store the cell’s energy reserves … Read more Storage Granules- Structure and Functions
Membrane Carbohydrate Cell membranes are selective barriers that separate individual cells and cellular compartments. Membranes are assemblies of carbohydrates, proteins, and lipids held together by binding forces. Carbohydrates are covalently linked to proteins (glycoproteins) or lipids (glycolipids) and also an important part of cell membranes, and function as adhesion and address loci for cells. The Fluid Mosaic Model describes membranes as a … Read more Membrane Carbohydrate
Nucleosome Model of Chromosome The chromosomes are the nuclear components of the special organization, individuality, and function that are capable of self-reproduction and play a vital role in heredity, mutation, variation and evolutionary development of the species. Each chromosome is made up of DNA tightly coiled many times around proteins that support its structure. The proteins that bind … Read more Nucleosome Model of Chromosome
