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)
The answer is to your question my friend is D.
Answer: . An organelle (think of it as a cell's internal organ) is a membrane bound structure found ... There are actually two different endoplasmic reticuli in a cell: the smooth ... which project into the extracellular space and act like a name tag for the cell.
Explanation:
Answer: 2. The rubbish is separated first by hand, then through flotation (separating plastic and paper), magnets, and an eddy current method, which pings off aluminium and other metals. A laser beam identifies each type of plastic as it passes on a conveyor belt, then a timed jet of air pushes it into the appropriate bin. There are two broad types of recycling operations: internal and external. Internal recycling is the reuse in a manufacturing process of materials that are a waste product of that process. Internal recycling is common in the metals industry, for example. 3. Repurpose Glass, Plastic and Cardboard Containers. One of the best uses for empty plastic soda bottles is as a planter for flowers and herbs. ...
Designate a Kitchen Drawer for Plastic Bags. ...
Reuse your Home Delivered Newspaper. ...
Supply Artists with Creative Materials. ...
Explanation:
Asthma is a chronic disease of the lung that has been increasing at an alarming rate in industrialized countries around the world over the last few decades. Although considerable progress has been made in our understanding of the underlying pathogenesis of the disease, the exact causes of the increasing prevalence are unknown. Studies suggest that most asthma develops in early childhood and that environmental factors present early in life may be crucial in the development of disease. One potential explanation for the recent epidemic referred to as the "hygiene hypothesis" postulates that factors that have resulted in a reduction in exposure to microbial products and/or infections in the western world may be contributing to this rise in disease prevalence. As early life influences are known to play an important role in establishment of asthma, studies have focused on the interface between mother and child that occurs during gestation and through breastfeeding. In this regard, the body of evidence regarding the relationship between breastfeeding and asthma indicates benefit but with the potential for risk. While providing population-level protection from infections and atopy in infancy and early childhood, breastfeeding might also pose an increased risk of atopic asthma among children with asthmatic mothers.
