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.
Food enters the stomach during the third stage of digestion, hope this helps.
C
Brown algae
Im pretty sure this is correct
Answer:
the answer is A. E. coli B
Explanation:
The multiplicity of infection (MOI) refers to the ratio between the numbers of viruses used to infect <em>E. coli</em> cells and the numbers of these <em>E. coli </em>cells. Benzer carried out several experiments in order to define the gene in regard to function. Benzer observed that <em>E. coli </em>strains with point mutations could be classified into two (2) complementary classes regarding coinfection using the restrictive strain as the host. With regard to his experiments, Benzer observed that rII1 and rII2 mutants (rapid lysis mutants) are complementary when they produce progeny after coinfect E. coli K (where neither mutant can lyse the host by itself). The rII group of mutants studied by Benzer does not produce plaques on <em>E. coli</em> K strains that carry phage λ (lysogenic for λ), but they produce plaques on <em>E. coli</em> B strains. This study showed that rIIA and rIIB are different genes and/or cistrons in the rII region.
Answer:
The Miller–Urey experiment (or Miller experiment) was a chemical experiment that simulated the conditions thought at the time to be present on the early Earth, and tested the chemical origin of life under those conditions. The experiment supported Alexander Oparin's and J. B. S.
Explanation:
