Category: Cell Organelles

Chromosomes Function

Chromosomes are the most important parts of the body that determine the shape, structure and character of a person. The chromosomes are made of DNA particles and protein material. There are totally 23 pairs of chromosomes in the human body responsible for various activities in the body. The last pair of chromosomes is sex chromosomes [Continue]

Cytoplasm Function

Cytoplasm – a mandatory part of the cells attached between the plasma membrane and the nucleus, divided into hyaloplasm (the main substance of the cytoplasm), organelles (the permanent component of the cytoplasm) and inclusion (the time components of the cytoplasm). Cytoplasm Function The chemical composition of the cytoplasm: the base is water (60-90% of the [Continue]

What Are Plastids

Plastids The membranous bound and pigment containing bodies present in the cell are called plastids. Plastids were Discovered by Schimper in 1883. Plastids are present only in plant cells and some algae. Plastids are semi-autonomous bodies of cells. They contain their own DNA and ribosome. So, they are self-replicating organelles. The newly form plastid is called [Continue]

Chemical Nature of Plasma Membrane

Physio Chemical Nature of Plasma Membrane The plasma membrane surrounds the cell. Chemically plasma membrane is composed of: Protein: 60 to 80% Phospholipids: 20 to 40% Cholesterol is in small amount Carbohydrates is in small amount Different models were put forward about the physiochemical nature of plasma membrane. Old Concepts Charles Overton: He found that [Continue]

Cytoplasm

Physio-Chemical Nature of Cytoplasm The living content of the protoplasm between the plasma membrane and nucleus is called cytoplasm. Living content of eukaryotes is divided into nucleus and cytoplasm. These living contents (nucleus and cytoplasm) collectively forms protoplasm. The cytoplasm has four components: Cytomembrane System It consists of well-defined structures, such as endoplasmic reticulum, mitochondria, [Continue]

Peroxisome And Glyoxisomes

Peroxisome Peroxisomes are cytoplasmic organelles. De-Duve and co-workers isolated peroxisome from liver cells and some other tissues. They are present in both animals and plants. They are also found in protozoa, yeast and many types of cells of higher plant. Structure: Peroxisomes are enclosed in a single membrane. Their size is 0.5 μm in diameter. [Continue]

Vacuole

Vacuole Vacuoles are the compartments within the protoplast bounded by the membrane tonoplast containing sap (aqueous solution). Vacuoles are present in both plant and animal cells. Both they are most abundant in plant cell. In plants, they occupy major part of the cell. Thus, the remaining intracellular structures form a thin peripheral layer. The numbers [Continue]

Ribosomes

Ribosomes Palade discovered ribosomes in 1953 in animals. Robinson and Brown discovered ribosomes in plant cells. Ribosomes are non-membranous bounded structures. Ribosomes are the sites where the cell synthesizes proteins according to genetic instructions. A bacterial cell may have a few thousand ribosomes. But a human liver cell has a few million ribosomes. Cells that [Continue]

Endoplasmic Reticulum

Endoplasmic Reticulum The word endoplasmic means “within” the cytoplasm. The word “reticulum” means the “network”. The Endoplasmic reticulum consists of a network of membranous tubules and sacs called cisternae. The ER are extensive in the cell. They are composed of more than half of the total membrane in many eukaryotic cells. The ER membrane separates [Continue]

Mitochondria

The Powerhouse Of The Cell Mitochondria is commonly called as power house of the cell. They provide energy transuding system. This system is used to change the food into chemical energy by oxidative phosphorylation. ATP is synthesized during oxidative phosphorylation. Discovery: Mitochondria was first described by Altmann in 1894. He named them as bioblast. He [Continue]