Answer: a tiny muscle connected to each hair follicle and the skin. When it contracts it causes the hair to stand erect, and a "goosebump" forms on the skin.
The step in translation initiation that is unique to the eukaryotes is:
<span>formation of the preinitiation complex ribosome assembly
</span>
Here are the processes involved in the Translation Initiation of Eukaryotes
1) 5'cap is used to position the mRNA on the 40S ribosomal subunit
2) ribosome scans down the mRNA looking for an AUG.
3) There is an initiator methionine-tRNA
4) The initiating AUG codon is often within a consensus sequence called the Kozak sequence (5'-ACCAUGG-3')
5) After binding the cap, ribosomes scan down the mRNA until the Kozak sequence is reached and translation begins
<span>6)The poly (A) tail and 5'-cap binding proteins help the initiation complex form
</span>
It is called Fluid Mosaic Model. It describes the structure of the plasma membrane as a mosaic component. The structures such as phospholipids, protein, carbohydrates and cholesterol gives the fluid like character of the plasma membrane.
<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
