The answer to this given question is the letter "C". The basis of immunoassay is the unknown amount of drug in a sample competes with the known amount os fluorescently labeled drug for binding to an antibody to that drug.
Answer:
total blood volume
Explanation:
Resistance to blood flow or vascular resistance refers to the slow down of the blood flow due to friction between the flowing blood and the walls of the blood vessels.
The resistance to blood flow is regulated by the viscosity of blood, total length, and diameter of the blood vessels. Higher blood viscosity imparts more resistance to the blood flow. The reduced diameter of blood vessels also restricts the blood flow through the blood vessels. Similarly, the resistance to the blood flow is directly proportional to the total length of the blood vessels.
However, total blood volume present in the body of the organisms does not affect vascular resistance. The total blood volume affects the blood pressure which in turn would affect the systemic vascular resistance.
Answer:
The correct answer is: d. REs activity is best preserved by freezing the RE and thawing it out for brief periods of time as needed.
Explanation:
- Restriction enzymes can be defined as endonucleases that can recognize specific nucleotide sequence in a DNA (Deoxyribonucleic acid) sequence and cause breakage of phosphodiester bond in the DNA at the target site. Hence, it has the capacity of cleaving a DNA sequence.
- These are made up of proteins which are required to be present in the accurately folded conformation in order to function.
- Any form of alteration in the three-dimensional structure of the protein induced due to physical, chemical, mechanical or physiological factors can cause denaturation of the protein which in turn can render the protein non-functional.
- Freezing of restriction enzymes (REs) directly without the use of glycerol will cause the movement of water molecules within the proteins as well layering of water molecules on the protein surface.
- At low temperature these water molecules change to ice crystals which can alter the conformation of the protein or can cause breakage of peptide bonds in the proteins by physical force.
- This can cause the protein to get denatured and hence non-functional.
- Hence, it is never advisable to preserve REs by freezing directly without glycerol.
- Glycerol forms a layer around the protein molecules and prevents the protein molecules from coming into direct contact with the water molecules and hence prevents protein denaturation.
