The correct answer is option A. They either match up with a receptor molecule on the surface of the cell or enter the cell through the membrane.
The intercellular signals are the signals, which transfer the signals from one cell to the another and the intracellular signals are those signals, which carries message within the cell.
The intercellular signals may or may not be transferred through the gap junctions. The chemical signals are one of the type of the cell signals. The chemical signalling molecules generally have a receptor on the cells, where these molecules can bind and can be cause the activation of the cell. The chemical signals can also enter into the cells through active transport and facilitated diffusion. So, these type of transports does not go through the Gap junction.
Surface tension is the property of water which allows for some lightweight insects to walk on top of a pond and not fall in. The molecules of water are held together by cohesive forces. The molecules of water present below the surface experience this cohesive force from all the directions, whereas the water molecules present on the surface experience a downward pull, as the force is not balanced. This leads to the concaving of the water surface inside a small tube.
Answer:
A series of nonpolar amino acids would most likely be located in the interior region of the tridimensional molecule.
Explanation:
Proteins are formed by linearly arranged amino acids, each with a side chain: the R-group.
Of the 20 different amino acids that compose the proteins, about half of them -10- are non-polar. Their R-groups are not stable if they are in contact with water, meaning that non-polar amino acids are hydrophobic.
When proteins are synthesized, they acquire a three-dimensional structure that makes them more stable. Lineal polypeptides get folded and turn into a shape that makes them more stable in the environment and capable of accomplishing their biological role. When they are in an aqueous media, their bent shape leaves the hydrophilic R-groups in contact with water. The hydrophilic R-groups stick in the center of the polypeptide, facing the protein interior, and avoiding interaction with water.
