lesson overview lesson overview carbon compounds chapter 2.3 carbon compounds

Lesson OverviewLesson Overview Carbon CompoundsCarbon Compounds

Chapter 2.3Chapter 2.3Carbon CompoundsCarbon Compounds


THINK ABOUT IT In the early 1800s, many chemists called the compounds created by organisms “organic,” believing they were fundamentally different from compounds in nonliving things.

We now understand that the principles governing the chemistry of living and nonliving things are the same, but the term “organic chemistry” is still around.

Today, organic chemistry means the study of compounds that contain bonds between carbon atoms, while inorganic chemistry is the study of all other compounds.


A. Chemistry of Carbon• Carbon atoms have four valence electrons, allowing them

to form strong covalent bonds with many other elements, including hydrogen, oxygen, phosphorus, sulfur, and nitrogen.

• Living organisms are made up of organic molecules that consist of carbon and these other elements.


B. Macromolecules• Many of the organic compounds

in living cells are macromolecules, or “giant biomolecules,” made from thousands of smaller molecules.

• The four major groups are:• carbohydrates• lipids• proteins • nucleic acids


Macromolecules

• The smaller units, or monomers, join together to form polymers.

• The monomers in a polymer, which are large molecules, may be identical or different.


1. Carbohydrates • Carbohydrates are

compounds made up of carbon, hydrogen, and oxygen atoms, usually in a ratio of 1 : 2 : 1.

• The breakdown of sugars, such as glucose, supplies immediate energy for cell activities.


a. Simple Sugars • Single sugars are also known as

monosaccharides.

• Besides glucose, they include galactose, which is a component of milk, and fructose, which is found in many fruits.

• Table sugar, sucrose, is an example of a disaccharide, a double sugar.


b. Complex Carbohydrates • 3 or more monosaccharides bonded together are

known as polysaccharides.

• Many animals store excess sugar in the muscles as glycogen.

• Plants use starch to store excess sugar. Found in grains, pasta, & potatoes.

Building blocks (or monomers) are monosaccharides.

Lesson OverviewLesson Overview Carbon CompoundsCarbon Compounds2. Lipids

• Lipids are made mostly from carbon and hydrogen atoms and are generally not soluble in water.

• One group of examples include fats, oils, and waxes.

• Lipids can be used to store backup energy. Which contains more energy, fats or carbs?

- it’s fats! 1g fat = 9 cal & 1g carb = 4 cal

• Another example is steroids. Some, such as hormones, serve as chemical messengers.


Lipids

• Many lipids are formed when building blocks like a glycerol molecule combines with compounds called fatty acids.


Lipids • Some lipids are

important parts of biological membranes and function as waterproof coverings.

• Phospholipids contain hydrophobic tails to repel water


3. Protein • Proteins contain atoms of nitrogen as well as

carbon, hydrogen, and oxygen.

• Proteins are polymers of molecules called amino acids

• Perform many functions, such as catalyzing biochemical reactions (controlling their speed), transporting substances into or out of cells, and helping to fight disease.


Protein • Covalent bonds called peptide bonds link its

building blocks, amino acids together to form a polypeptide.

• A protein is a functional molecule built from one or more polypeptides.


Protein • Proteins have a primary

structure of an amino acid sequence within a polypeptide.

• Then, polypeptide chains get twisted and folded. For example, the protein shown, hemoglobin, is found in red blood cells.


4. Nucleic Acids • Nucleic acids store and transmit hereditary,

or genetic, information.

• Contain the elements H, O, N, C, and

phosphorus (P).

• Nucleic acids are polymers assembled from monomers (or building blocks) known as nucleotides.


Nucleic Acids • There are two examples

of nucleic acids: ribonucleic acid (RNA) and deoxyribonucleic acid (DNA).

• RNA contains the sugar ribose and DNA contains the sugar deoxyribose.


Protein Amino acids differ from each other in a side chain called the R-group, which have a range of different properties.

More than 20 different amino acids are found in nature.

This variety results in proteins being among the most diverse macromolecules.


Macromolecules• Biochemists sort the

macromolecules found in living things into groups based on their chemical composition.

• Most are formed by a process known as polymerization (or dehydration synthesis), in which large compounds are built by joining smaller ones together.

lesson overview lesson overview carbon compounds chapter 2.3 carbon compounds

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