Cell Biology and Structure

These are mechanoreceptor. They are nerve endings present in the skin which are responsible for perception to vibration and pressure. Vibrational role is used by an individual to detect surface like rough vs. smooth.

Golgi bodies are also called lipochondria because temporary storage forms of lipids are found in the Golgi bodies.

Endoplasmic reticulum was originally known as ergastoplasm. The cytoplasm of the endoplasmic reticulum is interlaced by membranous vesicles, flattened sacs and cisternae.

Carcinoma is an epithelial tissue derived tumor.

Oxysomes are associated with the inner mitochondrial membrane. Oxysomes are also called F1 particles.

The nuclear lamina is composed of nuclear lamins that are associated with intermediate filaments having diameter of about 10 nm. Nuclear lamins belong to type V intermediate filament proteins.

The nuclear envelope of a typical mammalian cell contains 3000-4000 nuclear pore complexes.

Chloroplast is a double membranous cell organelle.

Spherosomes are specialised triacylglycerol filled vesicles known to arise from endoplasmic reticulum.

Quantasomes that are present on the surface of thylakoid membranes contain about 230 chlorophyll molecules.

It is a phospholipid occurring primarily in mitochondrial inner membranes and in bacterial plasma membranes. It is regarded as the heart of mitochondrial metabolism.

Astrocytes have many cytoplasmic processes terminating on blood vessels. These cells are engaged in all essential CNS functions, including blood flow regulation, maintaining the blood brain barrier, energy metabolism, ion and water homeostasis, immune defence of the body.

Microglia are regarded as the immune cells of the brain. After an injury, these cells undergo rapid change, altering their appearance, migrating to the site of the damage to help clear away and clean up dead, dying cells and cell debris.

Multicellular organisms develop a complex body structure and the cells are not exposed for long time to the air or water media for exchange of materials. Hence, specialized tissues become necessary to reach all the cells and do the needful activities like gaseous exchange, supply of food, removal of excretory products from all the cells. For this, cells do not increase in size; they are only more in number. Movements increase as a result of efficient working of tissues. Further, there are many multicellular organisms, which are small or minute in size. Hence, tissues are basis of structure and not size. 

A cell membrane is made up of bilayer of phospholipids. Phospholipids are made up of two fatty acids (long chains of hydrogen and carbon molecules), which are attached to a glycerol 'head'. The glycerol molecule is also attached to a phosphate group, and this is the hydrophilic part of the molecule. The 'tail' end of the fatty acid chains opposite the glycerol is the hydrophobic part of the molecule.