Answer
Compound can be taken up by cells via processes like phagocytosis ,
active transport , osmosis and facilitated diffusion . Large insoluble
particles may be taken into a cell by the process of phagocytosis . In this
process , the cell invaginates to form a cup-shaped depression to contain the
particle . The depression is then pinched of , forming a vacuole , which fuses
with lysosomes . Their enzymes then break down the particle and the useful
contents are absorbed . This process is used to obtain particles that are too
large for absorption via diffusion or active transport .
Active transport of compounds such as amino acids across call membranes
is done against a concentration gradient , i.e. from a reion of low
concentration to one of high concentration . Energy is required to drive the
process of active transport . This transport involves carrier proteins situated
in the cell surface membrane to carry the compounds across the membrane .
Osmosis involves the movement of water across the cell surface membrane
from a region of higher water potential to a region of lower water potential .
Thus , cells usually have lower water potential to ensure water is not lost .
Compounds such as glucose can be taken up by cells via facilitated
diffusion . This process involves carrier proteins to facilitate the transfer
of the substance down a diffusion gradient .
No comments:
Post a Comment