The best answer is D.
In active transport, molecules move against a concentration gradient from areas of lower concentration to areas of higher concentration. This happens a lot in neurons. The membrane proteins are constantly pumping ions in and out to get the membrane of the neuron ready to transmit electrical impulses.
In active transport , energy is required to move molecules across the cell membrane. Carrier proteins are needed for this e.g. proteins of the GLUT family which transport glucose molecules across the cell membrane. Carrier proteins are very specific. GLUT proteins will only move glucose molecules and not sodium or calcium. There are hundreds of types of carrier proteins.
Answer:
Diffusion helps animals in respiration. The cells in an animal's body need glucose and oxygen for respiration. Both these are carried in the blood. When blood reaches the cells the molecules of glucose and oxygen diffuse out of the blood and into the cells. As cells use up the glucose and oxygen they produce waste chemicals and carbon dioxide.
Diffusion is a very important process for photosynthesis where carbon dioxide from the stomata diffuses into the leaves and finally into the cells. This helps the plants to photosynthesize and produce more food.
Example for animals: Animals using glucose and oxygen in diffusion.
Examples for plants: Plants using carbon dioxide to photosynthesize.
Answer: cofactors.
Explanation:
Epinephrine, insulin and auxins are cofactors.
Cofactors are non protein substance which activate enzymes activity by increasing the rate of chemical reaction of enzymes. They are organic molecules and they assist in enzyme activity. They exist in performing some reactions the enzymes cannot perform alone.
For example, insulin activate enzyme hexokinase which phosphorylate glucose.
I don't think so, because for every action there is an equal and opposite reaction.
Hope this helps! :)
