Concept explainers
To discuss:
How carrier saturation and the transport maximum limit the carrier-mediated transport.
Introduction:
Cellular membrane, nucleus, and cytoplasm are the three major components of a cell. Cellular membrane, which surrounds the entire cell, is composed of phospholipids and proteins. The peripheral proteins are generally found on the membrane surface and are temporarily attached to one face of the plasma membrane. Membrane proteins that traverse the entire cell membrane alone can serve as a membrane channel. A membrane channel aids in the transfer of solutes from one side of the cell membrane, which is selectively permeable, to the other side of the membrane. Such integral proteins are called as transmembrane proteins.
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Anatomy and Physiology
- Which portion of the phosphotidylinositol molecules contributes to the fluidity of a membranearrow_forwardWhich statements are true? Explain why or why not.1 Transport by transporters can be either active orpassive, whereas transport by channels is always passive.2 Transporters saturate at high concentrations ofthe transported molecule when all their binding sites areoccupied; channels, on the other hand, do not bind theions they transport and thus the flux of ions through achannel does not saturate.3 The membrane potential arises from movementsof charge that leave ion concentrations practically unaf-fected, causing only a very slight discrepancy in the num-ber of positive and negative ions on the two sides of themembrane.arrow_forwardmembrane permeability for most of the compounds is directly proportional to their partition coefficient or their relative solubility in oil versus water true or falsearrow_forward
- summarizes several of the many types of transporters in the cells of the human body. List a few ways in which the variety of transport mechanisms shown here relate to the general principle of physiology that homeostasis is essential for health and survival.arrow_forwardMolecules cannot move naturally through tje selmembrane against its diffusion gradient,but it does.Explain this statement critically using the sodium-potassium pump diagramarrow_forwardthe maximal rate of solute movement during diffusion is greater than during mediated transport true or false?arrow_forward
- Suggest reason why iorganic ions such as K ,Na ,Mg ,Can do not cross biological membranes by simple diffusionarrow_forwardactive transport when no ATP is available is faster than when ATP is available true or false?arrow_forwardTrue or False: Passive-mediated transport proteins lower the delta G of transport to create the movement of molecules or ions.arrow_forward
- Human Physiology: From Cells to Systems (MindTap ...BiologyISBN:9781285866932Author:Lauralee SherwoodPublisher:Cengage Learning