Provided that there's no diagram, most molecules have particular areas on the molecules, called the "active area" that act as a lock to a particular substrate's molecular structure, providing the key.
An enzyme's active area is only able to be "unlocked" by a certain substrate's "key".
Answer:
a) 28 cases
b) 3 cases
Explanation:
a) From the table of genetic codes, there are 28 codons that specify more than one amino acid assuming only the first two nucleotides are considered. In these cases, one cannot outrightly specify the amino acid the genetic codes are coding for without knowing the last nucleotide of the codes. <em>For example, UU can be for Phenylalanine or Leucine, CA can be for Histidine or Glutamine, etc. </em>
b) From the table of genetic codes, the first two nucleotides of Arginine can be either of CG or AG, that of Serine can be either of UC or AG while that Leucine can be either of CU or UU. Only in these <u>3 cases</u> would one fail to know which are the first two nucleotides assuming the name of the amino acids are given.
<em>See the attached image for the genetic code.</em>
Flu vaccines need to be revised and changed every year because the flu virus constantly mutates. Flu viruses can change in two ways: drift or shift. Antigenic drift occurs when genes of the virus slowly change during replication until the immune system no longer recognizes it. On the other hand, antigenic shift occurs when a major change in the virus happens. This usually leads to a totally different kind of virus. This is what happened during the H1N1 scare in 2009.
DNA viruses like mumps are less prone to mutation due to the presence of DNA polymerase. RNA viruses are more prone to mutation because they undergo reverse transcription to simulate the role of DNA.
Answer:
Azurite and Magnesite react with hydrochloric acid.
Explanation:
These 2 rocks contain the carbonate mineral calcite dolomite. Carbonate minerals are unstable in contact with hydrochloric acid. When acid begins to effervesce (fizz) on a specimen, a reaction takes place and bubbles of carbon dioxide evolve, thus indicating the presence of minerals like calcite dolomite.
Hope my answer is correct and helpful :)
Answer:
1. import and export of nutrients and wastes
2. cell signaling
3. cell recognition
4. cell growth and motility
Explanation:
Plasma membranes are selectively permeable which means it only allows selective molecules to cross through it. So the plasma membrane helps in the import and export of nutrients by simple diffusion, facilitated diffusion or through active transport.
There are membrane protein embedded in the plasma membrane which have different role. Some help in cell signaling like GPCR, some help in cell recognition and some act and transporter proteins.
The plasma membrane is also responsible for cell growth and motility because it allow the raw materials and signals to pass through it which is required by the cell to metabolize and grow. So 1,2,3,4 is the correct answer.
