Answer:
The very first DNA isolation was done by a Swiss physician, Friedrich Miescher in 1869. He hoped to solve the fundamental principles of life, to determine the chemical composition of cells.
Answer:
Catalyst, in chemistry, any substance that increases the rate of a reaction without itself being consumed. Enzymes are naturally occurring catalysts responsible for many essential biochemical reactions.
Answer:
<u>Functions of epithelial tissue:</u>
- i. Epithelial tissue covers the body outside and lines the various cavities inside.
- ii. Epithelial tissue lines the hollow organs, body cavities, blood vessels and ducts.
- iii. Cells are rested on thin, doubled layered, non-cellular basement membrane.
- iv. Epithelial tissue has nerve supply of its own.
- v. Epithelial tissue is avascular (a = without, vascular = vessel), i.e. it lacks its own blood supply and hence, obtains nutrients which diffuse out of blood vessels.
- vi. Epithelial tissue has the power of division and regeneration. The old injured dead cells are sloughed off regularly and are replaced by new ones.
<h2>b) option is correct </h2>
Explanation:
- Some bacterial toxins cause disease by altering the activity of G protein, cholera toxin is one of them
- Cholera toxin catalyse ADP ribosylation of Gs and blocks GTPase activity thus Gs GTP become permanently active
- Constitutive activation of Gs protein continuously induce adenylyl cyclase, cytosolic cAMP level rises that leads to activation of protein kinase A (pKA)
- Activated pKA catalyse phosphorylation of two transmembrane proteins of intestinal epithelial cells:
- CFTR cause excessive outflow of Cl- ion and Na+ H+ exchange cause efflux of Na+ ion, both enters in gut and form Na+ Cl-
- Na+Cl- leads to outflow of water from the gut, resulting in diarrhea and dehydration and this condition may cause death of organisms due to loss of water and ions
The Moon's mass is lower than that of Earth, thus it's gravity is less dense than Earth's gravity.
Since the strength and gradient of gravity is both mass and density it would be reasonable to think about mads
