Download Organic Compounds

Organic Compounds (7.6A)
Student Expectation
The student is expected to identify that organic compounds contain carbon and other
elements such as hydrogen, oxygen, phosphorus, nitrogen, or sulfur.
Key Concepts
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Key Concept 1: Compounds that contain carbon are called organic compounds.
Key Concept 2: Many organic compounds often contain hydrogen, oxygen,
phosphorus, nitrogen and sulfur, in addition to carbon.
Key Concept 3: All living things are made up of organic compounds.
Elements are pure substances that cannot be broken down into any other substances by
chemical or physical means. Elements make up all of the different kinds of matter in the
universe either as single elements or in combination with other elements. The Periodic
Table of elements is a way of organizing all known elements by their physical and
chemical properties. An element is identified by its specific chemical and physical
properties. Each element has a chemical symbol, which is usually one or two letters
representing the element. If the symbol for an element is a single letter, then the letter is
always capitalized. If the symbol is two letters, then the first letter is always capitalized
and the second letter is lowercase. The symbols for each element are shown on the
Periodic Table and are used to represent elements in chemical formulas and equations.
Chemical symbols consist of letters of the Latin alphabet, although they are intended to
be used by people of all languages. Examples of elements with symbols based on Latin
names are copper (Cu- Cuprum), gold (Au – Aurum), and silver (Ag – Argentum).
Although there are a little more than 100 different elements in the world, only a small
number comprise a majority of the different systems on Earth. The elements that make up
rocks and minerals of solid Earth include silicon, oxygen, iron, magnesium, and other
trace amounts of various elements. Living organisms are composed primarily of carbon,
oxygen, and hydrogen. Other elements in living matter include calcium, nitrogen,
phosphorus, potassium, and trace amounts of other elements. Water is made up of
hydrogen and oxygen. The oceans also contain salt, made up of sodium and chlorine. The
atmosphere is mostly made up of the element nitrogen, existing in diatomic form (N2). It
also includes oxygen, carbon (in carbon dioxide) and a small amount of other elements.
Even though most of the other elements do occur naturally, they do so in very small
amounts compared to the limited number of elements making up the majority of Earth’s
systems. The most abundant elements on Earth are located within the first twenty
elements on the Periodic Table.
Elements consist of one type of atom distinguished by its atomic number which
represents the number of protons in its nucleus. An atom that has a different number of
protons represents a completely different element. Only a few elements exist in nature as
pure elements. Examples include nitrogen gas (N2), oxygen gas (O2), gold (Au), carbon
(C), silver (Ag), and copper (Cu). Many metals exist in pure element form. Most matter
consists of elements combined with other elements in a set ratio or proportion called
compounds. For example, water is a compound made of the elements hydrogen and
oxygen. The ratio of these elements is two hydrogen atoms and one oxygen atom for each
molecule of the compound water. Carbon dioxide gas is another example of a compound.
Any sample of carbon dioxide is always made of part carbon to two parts oxygen (CO2).
Salt, sodium chloride is made of one part sodium to one part chlorine (NaCl).
When elements are combined to make a compound, the new substance has properties
different from those of the original elements. For example, table salt is made of two
elements, sodium and chlorine. The properties of table salt do not represent the properties
of the individual elements. Sodium in element form is a highly reactive metal and
chlorine is usually a yellow-green gas in its natural state. When combined to make salt,
the properties of the compound are considerably different.
Organic compounds are compounds that contain one or more atoms of carbon covalently
bonded to atoms of other elements, most notably hydrogen, oxygen, phosphorus,
nitrogen, or sulfur. However, not all carbon-containing compounds are classified are
organic. Inorganic carbon compounds include carbon dioxide, carbon monoxide, metal
cyanides, carbonates and bicarbonates of metal ions, and a few others.
There are many organic compounds and the large number is possible because of carbon’s
ability to form strong covalent bonds to each other in addition to holding the atoms of
other nonmetals strongly. The properties of carbon also allow organic compounds to have
hundreds or even thousands of chains of carbon atoms (polymers). In addition, isomers,
compounds with similar molecular structures but different arrangements, increase the
number of organic compounds.
Many organic compounds are important for living organisms. Examples of organic
compounds can be found in carbohydrates (which include polysaccharides), lipids,
nucleic acids (including DNA and RNA as polymers), vitamins, enzymes, and amino
acids (monomer building blocks of proteins and peptides). Polysaccharides include
starches in animals and animals, as well as cellulose in plants. Another organic
compound in organisms includes ATP, adenine triphosphate.
Because of the large number of organic compounds, they are classified into groups, based
on the structure and number and types of elements present. Major groups of organic
compounds include alkanes, aldehydes, alcohols, carboxylic acids, ketones, esters,
sugars, cyanides, phenols, sulfides, just to name a few of the thousands of different
organic compounds.