Cell Organelles

Photsynthesis organelle is also referred by another name known as chloroplast. Chloroplasts are defined as the sub cellular organelle (Plastid) in green plants in which chlorophyll is present and process of photosynthesis takes place. The chloroplasts vary in shape, size from species to species. but typically, they are 1 – 2 μm (1 μm = 0.001 mm) thick and 5 ...

Following are test question answers for the plasma membrane and cytoplasm. Student can prepare these important question to prepare for any test. Give chemical composition of plasma membrane? Ans: Protein: 60 to 80%, Phospholipids: 20 to 40 %, Cholesterol in small amount, Carbohydrates in small amount. What was the model of E. Gorter and F. Grendel? Ans: They described that ...

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 the cisternal space from the ...

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 and is responsible for the ...

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 total mass of the cytoplasm), ...

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 protoplastid. It then changes into ...

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 the substances which dissolved in ...

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, plastids, Golgi apparatus, vacuoles and ...

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. In some mammalian tissues peroxisomes ...

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 of the vacuoles are different ...