Answer:
The correct answers are option A. "tethering proteins to the cell cortex", B. "using barriers such as tight junctions", C. "tethering proteins to the extracellular matrix", D. "forming a covalent linkage with membrane lipids", E. "tethering proteins to the surface of another cell"
Explanation:
According to the fluid-mosaic model, the components of cell membranes are in constant movement forming a barrier to avoid unwanted exterior component internalization and to avoid the loss of precious internal components. This constant movement could cause that proteins move across the plasma membrane. But, this is avoided by several mechanisms including:
A. Tethering proteins to the cell cortex. The cell cortex is a rigid structure made of actin and actomyosin. Proteins found in the plasma membrane are tethered to this structure to restrict their movement.
B. Using barriers such as tight junctions. Tight junctions are barriers found in epithelia made of claudin and occludin proteins. These barriers are impenetrable, which avoid the movement of proteins in the cell membrane.
C. Tethering proteins to the extracellular matrix. The extracellular matrix is made of several proteins and macromolecules that provide a structural and biochemical support to cells that are nearby. Proteins could be tethered to this rigid structure as well.
D. Forming a covalent linkage with membrane lipids. The proteins in the cell membrane that form a covalent linkage with membrane lipids are known as lipid-anchored proteins, or lipid-linked proteins.
E. Tethering proteins to the surface of another cell. When cell-cell communication take place it is possible that proteins in the cell membrane got tethered to the surface of the other cell.
So there are four types of mountains and these are fault block mountains, fold and thrust mountains, unwarped or dome mountains and volcanic mountains.
Based on the given locations above, the Sierra Nevada mountains of California are fault block mountains. The Alps of Europe is an example of a fold and thrust mountain. The Black Hills of South Dakota and Teton range of Wyoming are unwarped or dome mountains. Hope this answer helps.
The right answer is E. Sodium (with 140mmol/L)
Sodium is the most important element in the blood and extracellular liquids of the body.The needs of an adult subject are of the order of 1 to 2 g of sodium per day. The normal diet is much richer than our actual needs, about 4g, so it can largely compensate for the needs of an athlete or a runner.
Losses are majoritarly by feces and sweat. The kidney is able to reabsorb almost all the sodium that is filtered: urinary losses can be tiny.
Answer:
How are the nucleus and a vesicle similar and different in structure and function? Both are membrane-bound compartments that store and separate certain materials. The nucleus is an almost permanent structure protected by a double membrane bilayer, whereas a vesicle is a temporary organelle.
The answer to your question would be letter D
