Answer:
Atoms are electrically neutral as a result of having an equal amount of positive (due to the protons) and negative (due to the electrons) charges on it.
An ion generally is an electrically unbalanced atom (i.e an atom with a net charge on it)
A negative ion called an anion is produced when an atom gains an extra electron from a neighboring atom, giving it an extra negative charge. This can be produced by ionization with a radioactive radiation or simply by dissolution.
A positive ion is called a cation and it is produced when an atom loses electron to a neighboring atom. The loss of this electron causes the positive charges to outweigh the negative charges in the atom. Cations can be produced by radioactive radiation ionization of an atom or by simple dissolution.
The subatomic particle that is negative is the 'electron'.
Answer:
Enzyme- Peptidase/protease
Explanation:
According to this question, a student is conducting an experiment to determine the roles of molecules in metabolic processes such as digestion. Based on what she found out that the molecule, which itself can be broken down into amino acids, can also break down proteins into amino acids, this suggests that the molecule being described is a PROTEOLYTIC ENZYME.
This is because an enzyme is made up of proteins which can be denatured or broken down into its simplest unit (amino acids) and also, a substance that breaks down amino acid is said to be PROTEOLYTIC.
However, another observation that the molecule is found in high concentrations in the small intestine was made, hence, the enzyme is a PEPTIDASE OR PROTEASE, which are secreted into the small intestine by the pancreas to aid digestion of proteins.
The correct order is:
- Action potential arrives at the axon terminal.
- Calcium ions enter the axon terminal.
- Synaptic vesicles fuse to membrane of axon terminal.
- Acetylcholine is released into the synaptic cleft.
- Acetylcholine binds to its receptors on the junctional folds.
- Junctional folds become depolarized.
- Action potential is initiated on the sarcolemma.
Action potential travels through the membrane of the presynaptic cell causing the channels permeable to calcium ions to open. Ca2+ flow through the presynaptic membrane and increase the Ca concentration in the cell which will activate proteins attached to vesicles that contain a neurotransmitter (e.g. acetylcholine). Vesicles fuse with the membrane of the presynaptic cell, thereby release their contents into the synaptic cleft-space between the membranes of the pre- and postsynaptic cells. Neurotransmitter binds to its receptors on the postsynaptic membrane and its binding causes depolarization of the target cell (muscle cell).
