Science diary

CELL WALL  is the outer most layer of the cell. It can be tough, flexible or sometimes rigid. It acts as functional support and also as a filtering mechanism. It is present in most prokaryotes (except Mollicute bacteria) in algae, fungi and eukaryotes including plants but absent in animals and gamets and zoospore (motile spore).  It was first observed by Robert Hooke in 1665.  A detailed study of cell wall can be studied by: 1) COMPOSITION     -matrix     -microfibrills     -deposition 2) LAYERS     -Middle lamella     -Primary Cell Wall     -Secondary Cell Wall 3) FUNCTION 4) LOCATION So now let's start knowing about the composition  MATRIX:. -It is a grounded jelly like substance.  Its major component is H2O. It primarily consists of:  a) Hemicellulose:  These are polysaccharides. It contains five carbon sugar xylose and arbinose, the six sugar mannose and galactose and six carbon deoxy sugar rhamnose. Its major function is to provide strength to the plant cell wall. b) Pectin: I

Cell is the basic structural, functional and biological unit of all living organism. Often called as the "building blocks of life", Cell is the smallest unit of life. Cell has a rich and interesting history that has ultimately given way to many of today's scientific advancements. The history of cell is as follows: -In 1632-1723: Antonie Van Leevwenhook learned to make lenses and he constructed basic optical microscopes and drew protozoans (verticella) and bacteria from his mouth. -Initially founded by Robert hooke  in 1665 in a cork and then in living plant tissue using early compound microscope, he coined the name Cell ( in Latin: cella; meaning: small).  -In 1839, Theodor Schwann and Matthias Jakob Schledien elucidated the principle that plants and animals are made of cells and thus, founding the Cell Theory.   -In 1855, Rudolf Virchow stated that now cells come from pre-existing cells by cell division (Omnis cellula; ex cellula). Note: There was a belief that life form

To all those enthusiast science readers, right from our start of science lessons we have read about cell. Cell! Cell! Cell!  Today in this section we will learn about cell. A cell can be defined as the basic structural and functional unit of life. It performs various function. The major one among these is cell division which marks the Growth the most important of all. The cell cycle is the process which a cell undergoes to replicate all its materials and divide itself from one cell to two identical cells. The cell cycle consisted of 4-steps: 1. Gap 1 or G1 phase 2. Synthesis phase or S phase 3. Gap 2 or G2 phase  4. M phase or mitosis G1 phase: -It is often referred to as growth phase as this is the time when cell grows. - The cell synthesizes various enzymes and nutrients that are needed later on for DNA replication and cell division. - The G1 cyclin binds to cdk protein during G1 phase once bound and activated. - The cdk signals the cells exit from G1 phase and entry in S phase. S ph