Chemistry of Life: Carbon Compounds Ch. 2 Biology Ms. Haut

Carbon Compounds Organic Compounds –Contain Carbon –Derived from living things Carbon atom has four outer electrons, which can covalently bond with an electron from another atom

Properties of Carbon A carbon atom forms four covalent bonds –It can join with other carbon atoms to make chains or rings ESSENTIALS IN BIOLOGY WITH PHYSIOLOGY 2 nd edition, by Campbell and Reece, 2007

–The simplest organic compounds are hydrocarbons. These are organic molecules containing only carbon and hydrogen atoms. The simplest hydrocarbon is methane. –Larger hydrocarbons Are the main molecules in the gasoline we burn in our cars. –The hydrocarbons of fat molecules provide energy for our bodies. ESSENTIALS IN BIOLOGY WITH PHYSIOLOGY 2 nd edition, by Campbell and Reece, 2007

Macromolecules Most of the large molecules in living things are macromolecules called polymers –Polymers are long chains of smaller molecular units called monomers –A huge number of different polymers can be made from a small number of monomers Biology by Miller and Levine, © 2007.

Building Macromolecules Cells link monomers to form polymers by dehydration synthesis ESSENTIALS IN BIOLOGY WITH PHYSIOLOGY 2 nd edition, by Campbell and Reece, 2007

Breaking Down Macromolecules Polymers are broken down to monomers by the reverse process, hydrolysis ESSENTIALS IN BIOLOGY WITH PHYSIOLOGY 2 nd edition, by Campbell and Reece, 2007

Major Groups of Biological Macromolecules Carbohydrates Lipids Nucleic Acids Proteins

Carbohydrates Compounds made up of carbon, hydrogen, and oxygen –1C:2H:1O (C 6 H 12 O 6 ) Monomer units are monosaccharides (simple sugars) Disaccharides are made up of 2 simple sugars se.jpg

Glucose Maltose Copyright © 2003 Pearson Education, Inc. publishing Benjamin Cummings

Carbohydrates Polysaccharides —long chains of simple sugars Function as storehouse of energy –Starches —storage form of glucose in plants –Glycogen —storage form of glucose in animals Cellulose —tough fibers give plant strength and rigidity (found in wood and paper) ESSENTIALS IN BIOLOGY WITH PHYSIOLOGY 2 nd edition, by Campbell and Reece, 2007

Types of Lipids Large nonpolar molecules, made mostly of carbon and hydrogen –Fats –Waxes –Phospholipids –Steroids Can be used to store energy –Carbon-hydrogen bond store a lot of energy Lipids do not mix with water (hydrophobic)

Fats They are also called triglycerides –One glycerol molecule linked to three fatty acids Fatty acid Glycerol

Fats Saturated fatty acid — carbons contain the maximum number of hydrogen (animal fats, butter, lard) –Solid at room temp. Unsaturated fatty acid— carbons have double bonds; chains get kinked (plant oils, some fish oils) –Liquid at room temp.

Lipids Fats store energy efficiently –Have many more hydrocarbon (high energy) bonds than carbohydrates

Fats perform essential functions in the human body: Energy storage Cushioning Insulation Fats

Phospholipids Make up the lipid bilayer of cell membranes Makes cell membrane selectively permeable letter.php?newsletter_id=

Lipids Waxes—effective hydrophobic coatings (insects, plants, even humans) Fatty acid linked to alcohol Beeswax Waxy cuticle

Steroids 6 carbon rings; no fatty acid component Functions –Found in cell membranes—keeps fluid at  temps. –Serve as chemical messengers in the body (hormones) –Cholesterol-functions in the digestion of fats and starting material for hormones state.edu/~sabedon/campbl05_files/image013.gif

Nucleic acids are information-rich polymers of nucleotides Nucleic acids such and DNA and RNA store and transmit hereditary, or genetic, information. They ultimately control the life of a cell Nucleic Acids

The monomers of nucleic acids are nucleotides Phosphate group Sugar Nucleotides consist of three parts: a 5-carbon sugar a phosphate group a nitrogenous base Nitrogenous base (A) Copyright © 2003 Pearson Education, Inc. publishing Benjamin Cummings

Nucleic Acids There are two kinds of nucleic acids, ribonucleic acid (RNA) and deoxyribonucleic acid (DNA). –RNA contains the sugar ribose. –DNA contains the sugar deoxyribose.

Deoxyribonucleic acid DNA consists of two polynucleotides twisted around each other in a double helix The sequence of the four kinds of nitrogenous bases in DNA carries genetic information ESSENTIALS IN BIOLOGY WITH PHYSIOLOGY 2 nd edition, by Campbell and Reece, 2007

Stretches of a DNA molecule called genes program the amino acid sequences of proteins –DNA information is transcribed into Ribonucleic acid (RNA), a single-stranded nucleic acid –RNA is then translated into the primary structure of proteins ESSENTIALS IN BIOLOGY WITH PHYSIOLOGY 2 nd edition, by Campbell and Reece, 2007

A protein is a polymer constructed from amino acid monomers. Proteins perform most of the tasks the body needs to function –cellular structure –movement –defense –transport –communication –Enzymes regulate chemical reactions Proteins Copyright © 2003 Pearson Education, Inc. publishing Benjamin Cummings

Proteins are the most structurally and functionally diverse of life’s molecules –Their diversity is based on different arrangements of amino acids Proteins are made from just 20 kinds of amino acids Copyright © 2003 Pearson Education, Inc. publishing Benjamin Cummings

Each amino acid contains: –an amino group –a carboxyl group –an R group, which distinguishes each of the 20 different amino acids Amino group Carboxyl (acid) group Copyright © 2003 Pearson Education, Inc. publishing Benjamin Cummings

Each amino acid has specific properties Leucine (Leu)Serine (Ser)Cysteine (Cys) HYDROPHOBICHYDROPHILIC Copyright © 2003 Pearson Education, Inc. publishing Benjamin Cummings

Amino acids can be linked by peptide bonds Cells link amino acids together by dehydration synthesis The bonds between amino acid monomers are called peptide bonds

A protein, such as lysozyme, consists of polypeptide chains folded into a unique shape –The shape determines the protein’s function –A protein loses its specific function when its polypeptides unravel Overview: A protein’s specific shape determines its function Figure 3.14AFigure 3.14B Copyright © 2003 Pearson Education, Inc. publishing Benjamin Cummings

Protein Structure Primary structure The specific sequence of amino acids in a protein

A slight change in the primary structure of a protein affects its ability to function. The substitution of one amino acid for another in hemoglobin causes sickle-cell disease. ESSENTIALS IN BIOLOGY WITH PHYSIOLOGY 2 nd edition, by Campbell and Reece, 2007

Amino acid Hydrogen bond Alpha helix Pleated sheet Primary structure Secondary structure Secondary structure is polypeptide coiling or folding produced by hydrogen bonding Copyright © 2003 Pearson Education, Inc. publishing Benjamin Cummings Protein Structure

Polypeptide (single subunit of transthyretin) Transthyretin, with four identical polypeptide subunits Tertiary structure Quaternary structure Tertiary structure is the overall shape of a polypeptide Quaternary structure is the relationship among multiple polypeptides of a protein Copyright © 2003 Pearson Education, Inc. publishing Benjamin Cummings

What Determines Protein Structure? A protein’s shape is sensitive to the surrounding environment. –Unfavorable temperature and pH changes can cause a protein to unravel and lose its shape. –This is called denaturation.

Acknowledgements Unless otherwise noted, illustrations are credited to Prentice Hall and have been borrowed from Biology by Miller and Levine, © These images have been produced from the originals by permission of the publisher. These illustrations may not be reproduced in any format for any purpose without express written permission from the publisher. ESSENTIALS IN BIOLOGY WITH PHYSIOLOGY 2 nd edition, by Campbell and Reece, These images have been produced from the originals by permission of the publisher. These illustrations may not be reproduced in any format for any purpose without express written permission from the publisher. BIOLOGY: CONCEPTS AND CONNECTIONS 4th Edition, by Campbell, Reece, Mitchell, and Taylor, ©2003. These images have been produced from the originals by permission of the publisher. These illustrations may not be reproduced in any format for any purpose without express written permission from the publisher. BIOLOGY: CONCEPTS AND CONNECTIONS 4th Edition, by Campbell, Reece, Mitchell, and Taylor, ©2001. These images have been produced from the originals by permission of the publisher. These illustrations may not be reproduced in any format for any purpose without express written permission from the publisher.