THE STRUCTURE AND FUNCTION OF MACROMOLECULES Chapter 5

THE STRUCTURE AND FUNCTION OF MACROMOLECULES Chapter 5

I. _____ • A. Most _______ are polymers – 1. ______ consist of many similar building blocks linked by covalent bonds. – 2. The repeated units are called ______.

• B. _______ reactions build polymers. – 1. Monomers are connected by covalent bonds via a _______ reaction or dehydration reaction. (remove H 2 O, put together) – One monomer provides a hydroxyl group and the other provides a hydrogen and together these form water. – This process requires energy and is aided by enzymes.

2. Polymers are disassembled by ______. (add H 2 O, break apart) – In _____ as the covalent bond is broken a hydrogen atom and hydroxyl group from a split water molecule attaches where the covalent bond used to be. – ______ reactions dominate the digestive process, guided by specific enzymes. Copyright © 2002 Pearson Education, Inc. , publishing as Benjamin Cummings

C. Many polymers can be built from a small set of _____ • 1. The molecular model of life is simple: Small molecules common to all organisms are arranged into unique macromolecules. Monomers Polymers Single Sugars (monosaccharides) Carbohydrates Fatty Acids & Glycerol Lipids Amino Acids Proteins Nucleotides Nucleic Acids

II. ______ • A. _____ are divided into three classes: – Monosaccharides (“mono”=______) – Disaccharides (“di”=______) – Polysaccharides (”poly”=______)

B. Functions of Monosaccharides • 1. immediate ______ storage • 2. building blocks for other molecules such as ____, & ____.

C. Functions of Disaccharides 1. _______ sugars such as: • • Sucrose in plants. Lactose in mammals. 2. Short term ____ storage.

D. Functions of Polysaccharides • 1. _____ – a. Starch in plants. – b. Glycogen in animals. • 2. _____ – a. ____ in plants. – b. ____ in arthropods and fungi.

Structural Polysaccharides • ______ is the major structural polysaccharide in cell walls of plants. – Enzymes that hydrolyze starch are unable to hydrolyze cellulose due to linkages. – Very few organisms possess the enzymes necessary to hydrolyze cellulose.

• _____ is another structural polysaccharide. – It is found in the exoskeletons of arthropods (insects, spiders, crustaceans, etc. ). – Many fungi use ____ as cell wall material. • _____ is a monomer of glucose with a nitrogen containing group attached to the second carbon atom.

III. _______ • A. _____ are not polymers. – 1. Include fats, oils, waxes, phospholipids and steroids. – 2. ____ are hydrophobic. (water haters!) • B. _____ and oils are energy storage molecules. – 1. ______ also serve a protective function in animals. • C. _______ serve a protective function. (ear, leaf) • D. ______ make up all cell membranes. • E. _______ are signaling molecules. (hormones)

Fats, Oils, and Waxes • 1. Fats, oils, and waxes are constructed from molecules of _____ and fatty acids.

• 2. Fats are solid due to the single bonds between carbons. (____) • 3. Oils are liquid due to the presence of double bonds. (______)

_______ • 1. _____ are the major components of cell membranes. – a. two fatty acid tails. (hydrophobic) – b. a phosphate group. (hydrophilic) • _____ in water will “self-assemble” into groups so that their hydrophobic parts are shielded from water.

_______ • 1. _____ include cholesterol and certain other hormones. – a. ________ is a structural component of cell membranes. – Cholesterol is the building block from which other steroids are made.

IV. _____—The Molecular Tools • A. Polymers of amino acids are called _____ or proteins. 1. A protein consists of one or more polypeptides folded and coiled into a specific conformation. – 2. The amino acids that make up a polypeptide are all identical except for the group that is attached to the central carbon. – 3. Depending on what is attached to the central carbon, the amino acid may be polar, non-polar, or electrically charged.

• Polypeptides are made by _______ reactions. – Only the carboxyl and amine groups are involved in the reaction.

B. Structure of Proteins • 1. A proteins shape determines its function. • 2. Four levels of protein structure. – a. The ______ structure is its sequence of amino acids. – b. The ______ structure is the folding and coiling of parts of the chain. – c. The ____ structure is caused by bonding between the side chains. – d. The _____ structure results from two or more polypeptide chains combining into one protein.

• The primary structure of a protein is determined by the sequence of its _____ acids. • What determines the sequence of amino acids?

• The sequence of the primary structure is so important that a single amino acid _____ causes sickle-cell disease.

• C. _____ are proteins with tertiary structures. • Lysozyme, found in sweat, tears, and saliva, destroys molecules on the surface of many kinds of bacteria.

The folding of many proteins is protected by ______ proteins that shield outside influences.

• A protein’s conformation can change in response to the physical and chemical conditions. • D. Alterations in ____, _____, or other factors can unravel or _____ a protein. – These forces disrupt the hydrogen bonds, ionic bonds, and disulfide bridges that maintain the protein’s shape.

V. Nucleic Acids - Informational Polymers

A. ______ store and transmit _______ information • 1. There are two types of nucleic acids: _____ acid (RNA) and _____ acid (DNA). • DNA carries the instructions for life. • RNA reads the message of the DNA and translates it into a protein during protein synthesis. • Organisms inherit DNA from their parents.

• B. The flow of ____ information is from DNA -> RNA -> Protein. This is known as the “CENTRAL DOGMA of BIOLOGY” – Protein synthesis occurs in cellular structures called ____.

C. A ______ is a polymer of ______ 1. Each _____ consists of three parts: a nitrogen base, a pentose sugar, and a phosphate group.

• 4. Because of their shapes, only some bases are ______ to each other. – ____ (A) always pairs with _______ (T) and ____ (G) with _____ (C). • The two strands are _______.