24+Chemistry+of+Life

=Objectives= -What are the two major types of cells that occur in nature? -What compound is reduced during photosynthesis? What compounds are formed? -Where is glucose found abundantly in nature? -How can the cyclic forms of two simple sugars be linked? -What is the general structure of an amino acid? -Which functional groups are always involved in amide bonds between amino acids? -What determines the differences in the chemical and physiological properties of peptides and proteins? -How do enzymes affect the rates of reactions in living things? -What physical property distinguishes lipids from other classes of biological molecules? -How do phospholipid molecules arrange themselves in water? -What are the functions of DNA and RNA? -How long a base sequence of DNA is required to specify one amino acid in a peptide chain? -What are gene mutations? -What forms the basis for a method of identifying a person from biological samples? -What is recombinant DNA technology? -What is the function of ATP in living cells? -How does a cell obtain the energy and building blocks needed for the construction of new biological compounds? -What happens in a cell during anabolism? -How do nitrogen fixing bacteria provide plants with a useable form of nitrogen?

=Outlined Notes= A. The Structure of Cells** 1. Two major cell types occur in nature: the cells of bacteria, known as prokaryotic cells, and the cells of all other organisms, known as eukaryotic cells. 1. Photosynthesis uses the energy from sunlight to reduce carbon dioxide to compounds that contain C-H bonds, mainly in the form of glucose (C6H1206) a. __photosynthesis__ - a light-capturing system that converts light energy into chemical energy
 * I. A Strategy for Life
 * B. The Energy and Carbon Cycle**

A. Monosaccharides** 1. Glucose is abundant in plants and animals. a. __carbohydrates-__ monomers and polymers of aldehydes and ketones that have numerous hydroxyl groups attached; they are made up of carbon, hydrogen, and oxygen b. __monosaccharides-__ the simplest carbohydrate molecules are called simple sugars 1. The cyclic forms of two simple sugars can be linked by means of a condensation reaction. a. __disaccharide__- a sugar that forms from two monosaccharides b. __polysaccharides -__ the polymers produced by the linkage of many monosaccharide monomers
 * II. Carbohydrates
 * B. Disaccharides and Polysaccharides**

A. Amino Acids** 1. Amino acids have a skeleton that consists of a carboxyl group and an amino group, both of which are covalently bonded to a central carbon atom. The remaining two groups on the central carbon atom are hydrogen and an R group that constitutes the amino acid side chain. a. __amino acid-__ any compound that contains an amino group and a carboxyl group in the same molecule. 1. The amide bonds between amino acids always involve the central amino and central carboxyl groups. The side chains are not involved in the bonding. a. __peptide-__ any combination of of amino acids in which the amino group of one amino acid is united with the carboxyl group of another amino acid. b. __peptide bond -__ the amide bond between the carboxyl group of one amino acid and the nitrogen in the amino group of the next amino acid in the peptide chain 1. Differences in the chemical and physiological properties of peptides and proteins result from differences in the amino acid sequence a. __protein-__ a peptide with more than about 100 amino acids 1. Enzymes increase the rates of chemical reactions in living things a. __enzymes__- proteins that act as biological catalysts 2. How Enzymes Work a. __Substrates__- molecules on which an enzyme acts b. __active site__- the place on an enzyme where a substrate binds
 * III. Amino Acids and Their Polymers
 * B. Peptides**
 * C. Proteins**
 * D. Enzymes**

A. Triglycerides** 1. Lipids tend to dissolve readily in organic solvents, such as ether and chloroform, rather than in highly polar solvents such as water. This property sets them apart from most biological substances such as carbohydrates and proteins. a. __lipids__- fats, oils, and other water-insoluble compounds b. __triglyceride__- natural fats and oils exist as triesters of glycerol with fatty acids, which are long-chain carboxylic acids c. __saponification__- hydrolysis of oils or fats by boiling with an aqueous solution of an alkali- metal hydroxide 1. In water, phospholipids spontaneously form a spherical double layer, called a lipid bilayer, in which the hydrophobic tails of phospholipid molecules are sandwiched between two layers of hydrophilic heads. a. __Phospholipids__- lipids that contain phosphate groups, are abundant in cells 1. __Waxes__- esters of long-chain fatty acids and long-chain alcohols
 * IV. Lipids
 * B. Phospholipids**
 * C. Waxes**

A. DNA and RNA** 1. DNA stores the information needed to make proteins an governs the reproduction and growth of cells and new organisms. RNA has a key role in the transmission of the information stored in DNA and in the synthesis of proteins. a. __nucleic acids__- polymers that are found primarily in cell nuclei b. __nucleotides__- monomers that make up the DNA and RNA polymers 1. Three bases of DNA arranged in a specific sequence are required to specify one amino acid in a peptide or protein chain. a. __gene__- segment of DNA that carries the instructions for making one peptide chain 1. Substitutions, additions, or deletions of one or more nucleotides in the DNA molecule are called gene mutations. 1. The variation in the DNA of individuals forms the basis for a method of identifying a person from samples of his or her hair, skin cells, or body fluid. **E. Recombination DNA Technology** 1. Recombinant DNA technology consists of methods for cleaving a DNA chain, inserting a new piece of DNA into the gap created by the cleavage, and resealing the chain.
 * V. Nucleic Acids
 * B. The Genetic Code**
 * C. Gene Mutations**
 * D. DNA Fingerprinting**

=Reference Pages=

=Practice Problems=

=Assignments=

=Labs=

=Sample Test=

= = =**Links [] [] [] [] []**=