Answer:
The main factors affecting rate of photosynthesis are light intensity, carbon dioxide concentration and temperature.
Explanation:
Answer:the villi of the intestine
Explanation:like the cristae of the mitochondria which increase the surface area for the production of ATP,the villi of the intestine acts similarly.
In animals, digested food pass from the stomach to the intestine. In the intestine , enzymes acts on the food. Absorption of food takes place there and there are some structures that facilitates it. The walls of the intestine have numerous foldings , alongside the presence of finger like projection called villi. Microvilli are also presence from the cell walls of the intestine . These projections increase the surface area for the absorbing of food .they brush against food in the intestine and promotes absorption of nutrients.
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)
Tretinoin is a naturally occurring metabolite of retinol in the retinoid class, including natural and synthetic analogues. It is the acid form of vitamin AIt acts on cell growth and differentiation. Its main use is the treatment against acne thanks to its keratolytic and anti-inflammatory properties. Tretinoin is also used in the treatment of acute myeloid leukaemia type 3 (AML 3).
SIDE EFFECTS:
Among the expected effects, side effects may occur. Signs of an allergic reaction include: hives, difficulty breathing, swelling of the face, lips, tongue or throat;
It should be known that tretinoin can make you more sensitive to the sun, so use sunscreen every day, and wear protective clothing outdoors.
Cholesterol and triglycerides should be done before and during treatment because this drug could increase their values
Some patient with leukaemia treated by tretinoin has suffered from The syndrome of retinoic acid which is characterized by fever, dyspnea, acute respiratory distress...
