Posts

The plant cell

Image
P Plant Cell  A eukaryotic plant cell contains various cell organells like :  nucleus ,  chloroplast s,  mitochondria , a central vacuole,  Golgi apparatus , and  endoplasmic reticulum . The cell is surrounded by a  cell membrane  and further by cell wall.Presence of cell wall is its characteristic feature. Occurance of cell wall outside and a central large vacoule gives it rectangular shape. Internal structure of plant cell..  Plant cells (unlike animal cells) are surrounded by a thick, rigid cell wall. Plant cell organelles; Amyloplast An organelle in some plant cells that stores starch. Amyloplasts are found in starchy plants like tubers and fruits. Cell membrane - the thin layer of protein and fat that surrounds the cell, but is inside the cell wall. Cell wall- A thick, rigid membrane that surrounds a plant cell. This layer of cellulose fiber gives the cell most of its support and structure. The cell wall also bonds with other cell walls to form the structure of the plant. Centroso

The bacterial cell

The Bacterial cell Bacteria(sing. Bacterium) are microscopic, single-celled organisms that found in diverse environments. That means these organisms can live in soil, the ocean and inside the human gut. Humans' relationship with bacteria is complex. Sometimes bacteria serve as a helping hand, such as by  curdling milk into yogurt  or helping with our digestion. In other cases, bacteria are destructive, because they cause many diseases like pneumonia and others. Structure Bacteria (singular: bacterium) are classified as prokaryotes, which are single-celled organisms with a simple internal structure that lacks a nucleus, and contains  DNA  that either floats freely in a twisted, thread-like mass called the nucleoid, or in separate, circular pieces called plasmids.  Ribosomes  are the spherical units in the bacterial cell where proteins are assembled from individual amino acids using the information encoded in ribosomal RNA. Bacterial cells are generally surrounded by two protective c

Ribosomes

Ribosomes  are minute particles consisting of RNA and associated proteins that function to produce proteins. Proteins are needed for many cellular functions like repairing,damage or directing chemical processes.  Ribosomes  can be found floating within the cytoplasm or attached to the endoplasmic reticulum. Ribosome's Size Ribosomes comprise of two subunits that are composed and function as one to translate the mRNA into a polypeptide chain and protein synthesis.They vary in size between prokaryotic cells and eukaryotic cells. The prokaryotic ribosome is comprised of a 30s (Svedberg) subunit and a 50s (Svedberg) subunit meaning 70s for the entire organelle equal to the molecular weight of 2.7×106 Daltons. And Eukaryotic cell comprise of a 40s (Svedberg) subunit and a 60s (Svedberg) subunit which means 80s (Svedberg) for the entire organelle which is equal to the molecular weight of 4×106 Daltons. The ribosome word is derived – ‘ribo’ from ribonucleic acid and ‘somes’ from the Greek

Nucleus

Image
Nucleus  Nucleus The nucleus is a highly specialized organelle that serves as the information processing and administrative center of the cell.and it is called brain of cell also. This organelle has two major functions: it stores the cell's hereditary material, or DNA, and it coordinates the cell's activities, which include growth, intermediary metabolism, protein synthesis, and reproduction (cell division). Only the cells of advanced organisms, known as  eukaryotes , have a nucleus. Generally there is only one nucleus per cell, but there are exceptions, such as the cells of slime molds and the  Siphonales  group of algae. Simpler one-celled organisms ( prokaryotes ), like the bacteria and cyanobacteria, don't have a nucleus. In these organisms, all of the cell's information and administrative functions (Genetic material)are dispersed throughout the cytoplasm. The spherical nucleus typically occupies about 10 percent of a eukaryotic cell's volume, making it one of t

Mitochondria

Image
Mitochondrion. The mitochondrion is a semi autonomous double- membrane-bound organelle found in most eukaryotic organisms. Mitochondria known as... The “powerhouses of the cell”, that’s how many people know  mitochondria . The parts of cells that turn sugars, fats and proteins that we eat, into forms of chemical energy that the body can use to carry on living. Every living thing is made of cells: tiny compartments contained by a membrane.  Cells  are the smallest things that can reproduce themselves. When we look inside cells, we see that they have sub-compartments that are smaller still, known as “Organelles” which perform different functions that are essential for the cell to live. Mitochondria are organelles found in the cells of every complex organism.  They produce about 90% of the chemical energy that cells need to survive. And this energy is produced inside mitochondria.No energy; no life! So it's easy to see why when mitochondria go wrong, serious diseases are the result, a