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.
<span>Carbon is the building blocks of all living molecules. With the ability to form carbon-carbon bonds, many different compounds formed into different structures can be used for different purposes such as macromolecules. </span>
<span>The most serious complication that can appear in a client experiencing kidney failure is fluid retention. This could lead to swelling in your arms and legs or fluid in your lungs wich can cause a pulmonary edema so a client can happen a sudden death if not treated accordingly.</span>
<span>Joints with no movement are called immoveable or fibrous joints.They are also called synathrosis, they are only separated by a thin layer of fibrous connective tissue e.g are the sutures of the skull.
Joints that are more loosely connected are called freely moveable or synovial joints. They are also called diarthrosis.The joints are held together by an articular capsule comprised of ligaments. A synovial membrane lines the inside of the capsule and secretes synovial fluid which lubricates the joint (hence it's name).</span>
