Answer:
The correct insulin pathway is described as under:
2. Binding of insulin to the alpha subunit of the insulin receptor
8. Activation of insulin receptor tyrosine kinase
3. Phosphorylation of IRS proteins
6. Phosphorylation of phosphinositide 3-kinase (PI-3K)
4. Conversion of PIP2 to PIP3
7. Activation of PIP3-dependent protein kinase B (PDK1)
5. Glut4 receptors transported to the cell membrane
Explanation:
The insulin signaling pathway is described as under:
RTK (receptor tyrosine kinases) which is a receptor for insulin is an extracellular receptor but in contrast to other cell surface receptors it is catalytic in nature. In the absence of insulin (ligand), it is monomeric but as soon as it gets activated (activation occurs upon ligand binding), it undergo dimerization. It leads to auto-phosphorylation in it's tyrosine residue which subsequently leads to phosphorylation of tyrosine residue of other receptors. Such hyper-phosphorylated receptor have high affinity with enzyme/molecule like IRS protein which have SH2 domain . IRS down stream activates phosphinositide 3-kinase (PI-3K). This enzyme converts component of animal cell membrane PIP2 into PIP3. PIP3 also remains membrane bound but it has the potential to phosphorylate another enzyme named as PIP3-dependent protein kinase B (PDK1). Further, PDK1 leads to the activation of Akt or PK-B. Akt is a serine-threonine kinase which ultimately leads to the recruitment of Glut4 receptors on cell membrane for uptake of more and more glucose into the cell.
Note: Apart from this Akt also phosphorylates another protein named as FOXO which ultimately causes cell growth, Akt can also phosphorylate BAD protein so as to restrict cell apoptosis or we can say it leads to cell survival, Akt also leads to translation in a cell with the help of mTOR raptor etc.
It is also possible to move substances across membranes against their concentration gradient (from areas of low concentration to areas of high concentration). ... If the energy of ATP is directly used to pump molecules against their concentration gradient, the transport is called primary active transport.
Hope this helps
Answer:
meiosis
Explanation:
Down syndrome is an abnormality that occurs on chromosomes 21, it occurs because chromosomes 21 cannot be separated in meiosis, the pair of chromosomes 21 do not separate and go together to one of the daughter cells. In this way, the oocyte or the resulting sperm will have 24 chromosomes instead of 23. When in conception that oocyte or sperm joins the germ cell of its partner that contributes the 23 chromosomes, the total sum of chromosomes that will have the first cell of the new conceived being will be 47.
Answer:
c
Explanation:
all cells do not have an nucleus
