membrane activity

The transport of materials across the cell membranes with the help of energy is called active transport. Both diffusion and osmosis are passive transport mechanisms, not requiring energy. Active transport helps in the transport of ions across the membranes of..

The penetration of the sperm activates the egg and initiates a series of changes in the egg cortex and in the egg cytoplasm. Ovulation in the human female occurs at the secondary oocyte stage in which meiosis - I has been completed and the first polar body has been released but second mei..

This process is much faster and requires energy. A membrane pump operates across the cell membranes which transports the nutrients from the lumen of the intestine into the cells. This transport occurs with the help of ATP molecules. The carrier proteins in the membrane..

As a result of -subunit activity, a transducer G protein activates enzyme phosphodiesterase. This enzyme makes phosphatidylinositol 4,5-biphosphate (PIP 2 ) into a pair of mediators inositoltriphosphate (IP 3 ) and diacylglycerol (DG). In turn, IP 3 , which is water-soluble, an..

Taking food in the soluble forms into the tissues. This involves the absorption of food in the soluble form from the region of digestion into the tissues or into where it has to be utilised or into the blood stream which transports it to the different tissues. This takes place through the cell ..

Taking food in the soluble forms into the tissues. This involves the absorption of food in the soluble form from the region of digestion into the tissues or into where it has to be utilised or into the blood stream which transports it to the different tissues. This takes place through the cell ..

The part of the cell between the cell membrane and the nuclear membrane is called the cytoplasm. The cytoplasm consists of the matrix and the organelles. The matrix is a transparent semi fluid substance. When active, it is always in a state of movement. The organelles..

>The proteins present in the membrane may function as carriers or receptors or enzymes. Transport across membranes involves several mechanisms. There are processes like diffusion and osmosis, which do not require energy or activity of the cell. Diffusion involves movem..

This vitamin is named as tocopherol. Nearly about 8 tocopherols are identified - a , b , g etc. Among these -tocopherol is most active. Vitamin E is stored in adipose tissue, liver and muscle. It acts as a scavenger and is essential for membrane structure, cellular respirat..

This is a prominent, spherical or oval structure found at the centre of the cell. It is the controlling centre of all cell activities and has been described as the brain of the cell. It regulates all metabolic and hereditary activities of the cell. The nucleus is composed of th..