Answer/Explanation:
DNA polymerase is the enzyme responsible for replicating DNA. It is hugely important that is performs its functions accurately, as if incorrect bases are incorporated this can lead to mutations that disrupt the structure and function of genes. It adds nucleotides in a 5' - 3' direction only.
DNA polymerase III also has high processivity, which means that for every time it binds DNA, it is able to add many bases before it becomes dissociated.
A. DNA polymerase avoids the incorporation of improperly paired nucleotides in two ways:
- The first way depends on the structure of the enzyme. If the nucleotide that the enzyme is in the process of adding is not complementary to the template, then the nucleotide will not align with the template, and thus it is more inefficient to add. This inefficiency means the nucleotide is more likely to leave the active site before it is added, and DNA polymerase can replace it with the correct nucleotide.
- It also has proofreading capabilities. This means, when an incorrect base is added, it recognises the error and can fix this. It can do this because it possesses 3'-5' exonuclease activity. That means, it can chop out incorrectly added bases.
B. Ribonucleotides are the nucleotides that are incorporated into a growing RNA molecule. They are different from deoxyribonucleotides because of the differences in the sugar backbone (ribose vs deoxyribose). Their incorporation would disrupt the structure and function of the DNA, leading to problems with transcription and replication.
DNA polymerase avoids incorporating these nucleotides primarily because of the structure of the enzyme. Ribonucleotides cannot fit into the active site of DNA polymerase due to what is called a "steric filter" or "steric gate". This gate/filter function is performed by specific amino acid residues which usually have a bulky side chain and thus block the incorporation of the 2'OH of the ribose sugar (which is lacking in the deoxyribose sugar)
Answer:
Biodiversity is a variation of organisms (plants, animals and bacteria) in the world or a specific habitat. Biodiversity helps to keep an ecosystem healthy because there is more variation of food and different organisms can rely on each other for survival. Also it offers a larger more reliable food chain and if one species is suddenly wiped out, it won't impact the ecosystem as much as it would if the biodiversity was smaller.
Explanation:
Answer:
Feline Immunodeficiency Virus
Explanation:
The nucleus would be like the command center in the cell, because it monitors the cells functions and keeps everything "running smoothly".
Answer:
Friday to Predator??
Explanation:
Do you mean Prey to Predator, if so, On average, 90% of an organism's energy is used for its life processes and only 10% is passed on to its predator in the next trophic level. There are rarely more that 4 or 5 trophic levels in a food web.
