Answer:
The given statement is true.
Explanation:
A channel protein refers to a protein, which permits the conduction of particular substances like small molecules or ions through the cell membrane. They perform this task either through the process of active transport or facilitated diffusion on the basis of the concentration gradient or due to the variation in the concentration of components outside and within the cell membrane.
The answer is 100%. Three are observable, but the fourth is just a carrier.
Answer:
Explanation:
The cell membrane separates the cell from the outer environment. The extracellular fluid contains the sodium ions (Na+), chloride ions (Cl-), while intracellular fluid contains potassium (K +) and negative anions.
The potential difference arises when the membrane is selectively permeable to some ions. The resting potential is -70mV.
When the neurons get excited, the sodium ions start to enter by sodium channels.
Now there are more positive ions inside the cell membrane. It disturbs the resting potential i.e. -70mV. This stage is known as depolarization.
When the inside environment of the cell is more positively charged, the potassium ions start to move out of the cell. It goes out by the voltage-gated channels. Thus resting stage is maintained and it is known as repolarization.
But the initial stability of the cell membrane has to be maintained. To restore the resting stage, the sodium ions start to move out of the membrane and potassium ions enter into the cells again. This is an active transport and has done by the Na+ - K+ pump. Here 3 sodium ions move out and 2 potassium ions pumped into the cell through the plasma membrane.
Thus the resting potential regains. The potassium ions come back into the cells against the concentration gradient and ATP provides the energy for this phenomena.
Explanation:
Biological hazards include microorganisms such as bacteria, viruses, yeasts, molds and parasites. Some of these are pathogens or may produce toxins. A pathogenic microorganism causes disease and can vary in the degree of severity
The answer is A. When a potent drug is discovered, it has to undergo animal and human trials to test it ADMET (Absorption, Distribution Metabolism, Excretion, and Toxicity) properties. Using tissue cultures to test drugs, such as cancer drugs, prevents the incidence of subjecting humans to the unknown adverse effects of the drugs before the drugs are determined to be safe for use.
