INTRODUCTION Electrical properties of membranes are crucial to its function and the function of the cell as a whole. The membrane potential, which is the difference in electrical potential across the membrane, plays a critical role in a variety of cellular processes, including signaling, transport of ions and molecules, and…
FUNCTIONS OF ENDOPLASMIC RETICULUM The ER enables the movement of materials from one area of the cell to another, constituting the circulatory system of the cell. Desmotubule formation: Desmotubules are tubular extensions that stretch through plasmodesmata to connect the ER in two adjacent plant cells. Support – The cytoskeleton, which…
STRUCTURE OF ENDOPLASMIC RETICULUM The endoplasmic reticulum is often the biggest membrane in eukaryotic cells, forming a complex network of interconnecting membrane sacs or channels. It makes up 30 to 60 percent of a cell's entire membrane. Ribosomes may or may not be linked to the endoplasmic reticulum's outer membrane.…
Introduction and History Endoplasmic reticulum, the huge organelle, is made up of tubules and membranous sheets that extend across the entire cell and begin close to the nucleus. Many of the products made by a cell are manufactured and secreted by the endoplasmic reticulum, which also bundles them. One of…
INTRODUCTION Higher order chromatin structure comprises of nucleosomes and DNA which further form compact structures to fit 1-2 meter DNA into a very small nucleus. Earlier studies of chromosomes divided chromosomes divides chromosomal region into two categories : euchromatin and heterochromatin. Heterochromatin was characterized by dense staining with a variety…
INTRODUCTION The large human chromosome of humans contains 300 million base pairs. If it is in normal confirmation, it constitutes a chromosome over 10 cm in length. How can I fit all 46 chromosomes to a single nucleus? At the same time as being 10 µm in diameter, it keeps…
INTRODUCTION Tumor suppressor genes and oncogenes are important regulatory genes which encode proteins regulating transitions in and out of the cell cycle and which also have a role in the gateway to terminal differentiation. Defects in tumor suppressor genes and oncogenes result in uncontrolled cell division, which leads to cancer.…
INTRODUCTION Human papillomavirus (HPV) infection is the most common sexually transmitted disease worldwide with the highest prevalence in young women and men. Most sexually active individuals of both sexes will acquire a genital HPV infection at some point in life. While most HPV infections resolve spontaneously within two years, the…
Viruses are very small submicroscopic biological entities which though lack plasma membrane and metabolic machinery. Viruses require some host cell that is they are obligate cellular parasites of either bacteria, plants or animals. There genetic material is can be RNA or DNA.
A disease in which cells divide abnormally and destroy body tissues. Three classes of genes are responsible for the onset of cancer. First one is proto oncogene the normally promotes cell growth. After mutation proto-oncogene changes into oncogene whose products are excessively active in growth promotion.