- Water and living organisms
- The Common Types of Chemical Reactions
- Features of the interaction of sulfur and water
Water and living organisms
Types of Chemical Reactionswith neymar da silva santos jÃºnior microsoft remote desktop session host server network provider
It can be quite correctly argued that life exists on Earth because of the abundant liquid water. Other planets have water, but they either have it as a gas Venus or ice Mars. This relationship is shown in Figure 1. Recent studies of Mars reveal the presence sometime in the past of running fluid, possibly water. The chemical nature of water is thus one we must examine as it permeates living systems: water is a universal solvent, and can be too much of a good thing for some cells to deal with.
Hydrolysis , in chemistry and physiology , a double decomposition reaction with water as one of the reactants. The reactants other than water, and the products of hydrolysis, may be neutral molecules —as in most hydrolyses involving organic compounds —or ionic molecules, as in hydrolyses of salts , acids , and bases. The hydrolysis involves several steps, of which the slowest is the formation of a covalent bond between the oxygen atom of the water molecule and the carbon atom of the ester. In succeeding steps, which are very rapid, the carbon—oxygen bond of the ester breaks and hydrogen ions become detached from the original water molecule and attached to the nascent alcohol molecule. A characteristic feature of the hydrolysis of esters and of most other organic compounds is that a third substance, ordinarily an acid or a base, increases the rate at which the chemical change takes place. In the biochemical process of digestion , enzymes secreted by the digestive tract catalyze the hydrolysis of complex molecules into forms that the body organisms can assimilate. Proteins are decomposed to amino acids , fats to fatty acids and glycerol , and starches and complex sugars to glucose and other simple sugars; enzymes such as lipases , amylases , and proteinases catalyze the hydrolysis of fats, carbohydrates , and proteins, respectively.
Oxides are chemical compounds with one or more oxygen atoms combined with another element e. Oxides are binary compounds of oxygen with another element, e. These are termed as oxides because here, oxygen is in combination with only one element. Based on their acid-base characteristics oxides are classified as acidic, basic, amphoteric or neutral:. There are different properties which help distinguish between the three types of oxides. The term anhydride "without water" refers to compounds that assimilate H 2 O to form either an acid or a base upon the addition of water. Acidic oxides are the oxides of non-metals Groups and these acid anhydrides form acids with water:.
The term is used broadly for substitution , elimination , and fragmentation reactions in which water is the nucleophile. Biological hydrolysis is the cleavage of biomolecules where a water molecule is consumed to effect the separation of a larger molecule into component parts. When a carbohydrate is broken into its component sugar molecules by hydrolysis e. Generally, hydrolysis or saccharification is a step in the degradation of a substance. Hydrolysis reactions can be the reverse of a condensation reaction in which two molecules join together into a larger one and eject a water molecule.
Chapter 1 Chapter 1: The Chemical World 1. When some substances are dissolved in water, they undergo either a physical or a chemical change that yields ions in solution. These substances constitute an important class of compounds called electrolytes. Substances that do not yield ions when dissolved are called nonelectrolytes. If only a relatively small fraction of the dissolved substance undergoes the ion-producing process, it is called a weak electrolyte. Substances may be identified as strong, weak, or nonelectrolytes by measuring the electrical conductance of an aqueous solution containing the substance. To conduct electricity, a substance must contain freely mobile, charged species.
The Common Types of Chemical Reactions
Several general types of chemical reactions can occur based on what happens when going from reactants to products. The more common types of chemical reactions are as follows:. In combination reactions , two or more reactants form one product.
Features of the interaction of sulfur and water
These roles can be explained once we have understood the structure and bonding in a water molecule, and between water molecules. Water is a molecular compound, with molecular formula H 2 O. The atoms in a water molecule are held together by strong covalent bonds. These are very difficult to break. Water - click on image to open. The dot-and-cross diagram for a water molecule shows there are two bonding pairs of electrons and two non-bonding pairs of electrons.