Answer:
peptide antigens by MHC class II molecules
Explanation:
Helper T cells are activated by peptide antigens by MHC class II molecules. These antigens express on the surface of antigen-presenting cells (APCs). After activation, the T helper cells divide and secrete cytokines to assist the immune response.
<span>C. more solute
A hypertonic solution has a higher concentration of solute outside than inside the cell.</span>
Answer:
false
Explanation:
a hormone is not an organ that secretes chemical substances into the bloodstream, hence your answer is false
hope that helps! :)
Answer:
No, glycolysis can not be continued without fermentation in the absence of oxygen.
Explanation:
In the absence of oxygen, cells perform fermentation to oxidize NADH into NAD+. NAD+ is required during the conversion of glyceraldehyde 3 phosphate into 1,3 bisphosphoglycerate. Fermentation reduces pyruvate and oxidizes NADH so that the NAD+ supply is continued to ensure continuity of glycolysis.
If fermentation does not occur under anaerobic conditions, cells will accumulate pyruvate and NADH. Glycolysis could not be continued in the absence of NAD+.
