membrane structures that function in active transport

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 transp..

It is a process by which certain substances like glucose molecules are transported against the concentration gradient. The carrier proteins in the cell membrane carry out the process. The substance present in the medium binds with the active site on the carrier pr..

The human heart is a muscular, cone-shaped, hollow organ about the size of a fist (about 12cm in length and 9cm in breadth). The heart is situated behind the sternum, between the lungs in the thoracic cavity. The heart is tilted slightly such that its apex is towards the left side. The major p..

The plasma membrane or cell membrane surrounds the cell contents in all types of cells. It is a multipurpose covering composed of phospholipids and proteins. fig. 16.4 - Cell Membrane Apart from the plasma membrane, an eukaryotic cell also shows intracellular..

These membranes are formed outside the embryo from the trophoblast and perform specific functions..

>Each alveolar duct opens into an alveolar sac. Alveolar sac is the extended region into which a group of alveoli or air sacs open. Each alveolus is a sac-like structure lined by a single layer of epithelial cells. It is bound on the outside by a network of capillaries. All the alveoli on..

The molecular structure of cell membrane is still not clearly known. Several models have been proposed from time to time to explain its structure based on its physico-chemical properties. In the year 1935 Danielli and Dawson proposed that the cell membrane is..

Transport of Minerals - Minerals are absorbed from the soil along with water as they are dissolved in water. They are taken up in the ionic form . For example, potassium is taken up as K + ions. They are transported through the xylem along with the water. Some of the mineral ion..

Minerals are absorbed from the soil along with water as they are dissolved in water. They are taken up in the ionic form . For example, potassium is taken up as K + ions. They are transported through the xylem along with the water. Some of the mineral ions like the nitrates enter into ..

) or secretory products (gums, alkaloids, hormones, etc) or excretory products (calcium carbonate and other salts). These substances are generally stored in the vacuoles. Cell organelles are mainly of two types membrane-bound and non-membranous. Membrane bound organell..