Section 2–3 Carbon Compounds

This section explains how the element carbon able to form millions of carbon, or organic, compounds.

It describes the four groups of organiccompounds found in living things.

Life’s Backbone

• Most of the compounds that make up living things contain carbon. In fact, carbon makes up the basic structure, or “backbone,” of these compounds. Each atom of carbon has four electrons in its outer energy level, which makes it possible for each carbon atom to form four bonds with other atoms.

• As a result, carbon atoms can form long chains. A huge number of different carbon compounds exist. Each compound has a different structure. For example, carbon chains can be straight or branching. Also, other kinds of atoms can be attached to the carbon chain.

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What are organic compounds?

• organic compounds are compounds that contain carbon.

• Inorganic compounds are compounds that do not contain carbon ex. Water

• Hydrocarbon is a compound that contains only the elements carbon and hydrogen

• Ex. methane

The Chemistry of Carbon

How many valence electrons does each carbon atom have?

Each carbon atom has four electrons.

What gives carbon the ability to form chains that are almost unlimited in length?

A carbon atom can bond to other carbon atoms.

Many of the molecules in living cells are so large that they are known as Macromolecules

What is the process called by which macromolecules are formed? Polymerization

When monomers join together, what do they form? Polymers

• carbohydrates (sugars and starches), • lipids (wax,fats,oil) • Proteins, (ex. Alanine, glycine …) • nucleic acids (DNA and RNA).

• These molecules are usually in the form of polymers, long chains of similar subunits. Because they are large, these molecules are called macromolecules. The subunits are called monomers.

• The cell also contains water, inorganic salts and ions, and other small organic molecules.

WHAT ARE FOUR GROUPS OF ORGANIC COMPOUNDS FOUND IN LIVING THINGS?

Carbohydrates are made of Carbon, hydrogen, and oxygen atoms ex. Sugars and starches

Function: main source of energy.

Monosaccharides are Single sugar molecules. Ex. Galactose, glucose and fructose

Polysaccharidesare large macromolecules formed from monosaccharidesEx. Glycogen

Carbohydrates

Nucleic acids

Nucleic acids contain hydrogen, oxygen, nitrogen, carbon, and phosphorus atoms.

Function: Nucleic acids store and transmit hereditary, or genetic, information.

The two types of nucleic acids:• Deoxyribonucleic acid (DNA)• Ribonucleic acid (RNA)

Nucleotide Nucleotides are molecules that, when joined together, make up the structural units of RNA and DNA.

The nucleotide consists of a nitrogenous base, a phosphate group, and a 5-carbon sugar.

PROTEINS

proteins contain nitrogen, carbon, hydrogen, and oxygen atoms.

Amino acids are the building blocks of proteins.

What are four roles that proteins play in living things?

• Some control the rate of reactions and regulate cell processes.

• Some are used to form bones and muscles.

• Some transport substances into or out of cells.

• Some help to fight diseases.

Lipids lipids are mostly made of carbon and hydrogen

The three common categories of lipids are fat, oils and wax

CarbonCompounds

include

that consist of

which contain

that consist of make up the structural units of RNA and DNA.

building blocks of proteins

which contain which contain which contain

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Concept Map

Carbohydrates Lipids Nucleic acids Proteins

Sugars and starches

Fats and oils Nucleotides Amino Acids

Carbon,hydrogen,

oxygen

Carbon,hydrogen,

oxygen

Carbon,hydrogen,oxygen, nitrogen,

phosphorus

Carbon,hydrogen,oxygen,

nitrogen,

Functions functions functions functions

Class work: The Chemistry of Carbon

1. How many valence electrons does each carbon atom have? Each carbon atom has fourlectrons.2. What gives carbon the ability to form chains that are almost unlimited in length? A carbon atom can bond to other carbon atoms.Macromolecules3. Many of the molecules in living cells are so large that they are known as __________

4. What is the process called by which macromolecules are formed?____________ Polymerization5. When monomers join together, what do they form? ___________Polymers6. What are four groups of organic compounds found in living things?a.b.c.d.Carbohydrates7. What atoms make up carbohydrates? Carbon, 8. What are polysaccharides?

Methane Acetylene Butadiene Benzene Isooctane

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Figure 2-11 Carbon Compounds

Starch

Glucose

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Figure 2-13 A Starch

carbohydrate

General structure Alanine Serine

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Figure 2-16 Amino Acids

Amino group Carboxyl group

Poteins

• 1. On a sheet of paper, make a list of at least ten things that contain carbon.

• 2. Working with a partner, review your list. If you think some things on your list contain only carbon, write “only carbon” next to them.

• 3. If you know other elements that are in any items on your list, write those elements next to them.

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