Answer:
It means that the cell membrane allows certain substances to pass through and not others. As the cell membrane consists of a phospholipid bilayer with a hydrophobic core, only small uncharged hydrophobic molecules can pass through the cell membrane e.g. glucocorticoid and other larger charged particles require transporters or channel proteins to pass through the cell membrane, e.g. glucose.
Antibodies bind to the antigens on the surface of disease agents. If some sort of fluorescent tag is added to the antibody it would make the disease agent be identifiable either under a microscope or with other Instruments because it would bind to the antigens on the surface of the disease agents and make them glow a certain color. I hope that this is the answer that you were looking for and it has helped you.
Food, shelter, water, are some things a squirrel will need to survive
Smooth muscles (but depending on the specific type)
<span>Electrons are transferred via Hydrogen atoms bound to NAD (nicotinamide adenine dinucleotide). Essentially, the krebs cycle harvests electrons (Hydrogen atoms) from pyruvates in the inter-membrane space via NADH and these feed into the electron transport chain to power ATP synthase to generate ATP.</span>