Membranes are highly fluid, dynamic structures consisting of a lipid bilayer and associated proteins. Plasma membranes form closed compartments around the cytoplasm to define cell boundaries. The plasma membrane has selective permeabilities and acts as a barrier, thereby maintaining differences in composition between the inside and outside of the cell. Selective membrane molecular permeability is generated through the action of specific transporters and ion channels. The plasma membrane also exchanges material with the extracellular environment by exocytosis and endocytosis, and there are special areas of membrane structure—gap junctions—through which adjacent cells may exchange material. In addition, the plasma membrane plays key roles in cell-cell interactions and in transmembrane signaling

Membranes also form specialized compartments within the cell. Such intracellular membranes help shape many of the morphologically distinguishable structures (organelles), for example, mitochondria, ER, Golgi, secretory granules, lysosomes, and the nucleus. Membranes localize enzymes, function as integral elements in excitation-response coupling, and provide sites of energy transduction, such as in photosynthesis (chloroplasts) and oxidative phosphorylation (mitochondria)

These questions will give you basic idea for Examination Preparation and/or interview on Membrane Structure and Functions.

Please Note:

1. These questions are only for practice and understanding level of knowledge only. It is not necessary that these questions may or may not appear for examinations and/or interview questions

2. In this practice test, because of large amount of questions (around22 questions) some of questions may have repeated

3. I had to put as 70% pass rate because there may also be wrong answers from my side