MRS. GEISLER BIOCHEM MACROMOLECULES

What do you know? True or False Thumbs up for TRUE Thumbs down for FALSE Monomers are complex large molecules. FALSE

What do you know? True or False Thumbs up for TRUE Thumbs down for FALSE DNA is a macromolecule. TRUE

What do you know? True or False Thumbs up for TRUE Thumbs down for FALSE Sugar is a carbohydrate. TRUE

What do you know? True or False Thumbs up for TRUE Thumbs down for FALSE Protein stores energy. FALSE

What do you know? True or False Thumbs up for TRUE Thumbs down for FALSE Lipids store more energy than carbohydrates. TRUE

STUDENT LEARNING OBJECTIVES Students will explain how carbon is uniquely suited to form biological macromolecules (ref. BIO.A.2.2.1). Students will compare the structure and function of carbohydrates, lipids, proteins, and nucleic acids in organisms (ref. BIO.A.2.2.3). Students will describe how biological macromolecules form from monomers (ref. BIO.A.2.2.2).

MACROMOLECULES Very large molecules ( polymers ), made up of smaller organic molecules called monomers. (*MONOPOLY – one person owning all properties!) Made up of: nitrogen (only in proteins), oxygen, hydrogen, and carbon. BREAK IT DOWN! Macro - large Mono – one Poly - many

WHAT ARE THE 4 MACROMOLECULES? 1.Carbohydrates 2.Proteins 3.Lipids 4.Nucleic Acids

CARBON So unique! Can bond to itself and other elements to make many different types of compounds.

CARBOHYDRATES Act as quick energy source within bodies of living organisms. Monosaccharides as their monomers. Examples of monosaccharides: glucose, fructose, galactose BREAK IT DOWN! Mono – one Sacchar - sugar

PROTEINS In animals, used in muscle-building and growth. In plants, act as an essential part of their structure. Enzymes are proteins. Amino acids are the monomers of proteins. Only macromolecule that contains Nitrogen.

LIPIDS Lipids are used as stored energy. Fats and oils Lipids’ base units aren’t considered monomers. Building blocks of lipids are: Glycerol + 3 fatty acids = triglyceride (lipid)

NUCLEIC ACIDS DNA and RNA Made up of: 1.sugar 2.phosphate 3. nitrogenous base. (Adenine, Cytosine, Guanine, Thymine) The order of the nitrogenous bases determines the information. Proteins are made from the sequences of the bases.

HOW ARE POLYMERS FORMED? Dehydration synthesis reaction: monomer + monomer  polymer + water

REVIEW (FROM THE BIO KEYSTONE PRACTICE TEST)

3-19 NOTES Carbohydrates Starch  plants = cellulose animals = glycogen Starches are large polysaccharides. Glycogen can be broken down into glucose to give quick energy to animals.

PROTEINS Monomer = amino acid, carboxyl group, R group. R group = carbon chain or ring. The R group determines what type of amino acid it is. There are 20 different amino acids

ENZYMES Many proteins are enzymes. Enzymes  start chemical reactions. ( catalysts ) Ex. Proteases are enzymes that break down peptide bonds between amino acids in meat that you eat. Substrates = red and green Enzyme = yellow Products = pink The enzyme makes the chemical rxn. happen Active site

ENZYMES Enzymes are sensitive to temperature and pH. Ex. When you cook an egg it coagulates and loses its shape.

LIPIDS There are more C-H bonds in lipids not C- O like in carbs. The C-H bonds pack more energy thus  lipids store more energy. Monomers: 3 fatty acid and carboxyl group (COOH)

STEROIDS Steroids are lipids because they are hydrophobic Function : reproduction, absorption, metabolism regulation & brain activity. Structure : 4 carbon rings Ex. Testosterone, cholesterol.

LIPIDS Phospholipid – found in the cell membrane, helps to create a barrier for the cell.

Condensation Synthesis

HYDROLYSIS What is a hydrolysis reaction? Polymers are broken down into monomers. Hydro = water; lysis = loosening/ Water is added and the lysis of the polymer occurs.

HYDROLYSIS

II. CLASSES OF ORGANIC MOLECULES: What are the four classes of organic molecules? Carbohydrates Lipids Proteins Nucleic Acids

A. CARBOHYDRATES Sugars Carbo = carbon, hydrate = water; carbohydrates have the molecular formula (CH 2 O) n Functions: Store energy in chemical bonds Glucose is the most common monosaccharide Glucose is produced by photosynthetic autotrophs

1. STRUCTURE OF MONOSACCHARIDES An OH group is attached to each carbon except one, which is double bonded to an oxygen (carbonyl).

Classified according to the size of their carbon chains, varies from 3 to 7 carbons. Triose = 3 carbonsPentose = 5 carbonsHexose = 6 carbons

In aqueous solutions many monosaccharides form rings:

2. STRUCTURE OF DISACCHARIDES Double sugar that consists of 2 monosaccharides, joined by a glycosidic linkage. What reaction forms the glycosidic linkage? Condensation synthesis

EXAMPLES OF DISACCHARIDES: Lactose = glucose + galactose Sucrose = glucose + fructose

3. POLYSACCHARIDES Structure: Polymers of a few hundred or a few thousand monosaccharides. Functions: energy storage molecules or for structural support:

Starch is a plant storage from of energy, easily hydrolyzed to glucose units Cellulose is a fiber-like structural material - tough and insoluble - used in plant cell walls Glycogen is a highly branched chain used by animals to store energy in muscles and the liver. Chitin is a polysaccharide used as a structural material in arthropod exoskeleton and fungal cell walls.

B. LIPIDS Structure: Greasy or oily nonpolar compounds Functions: Energy storage membrane structure Protecting against desiccation (drying out). Insulating against cold. Absorbing shocks. Regulating cell activities by hormone actions.

1. STRUCTURE OF FATTY ACIDS Long chains of mostly carbon and hydrogen atoms with a -COOH group at one end. When they are part of lipids, the fatty acids resemble long flexible tails.

SATURATED AND UNSATURATED FATS Unsaturated fats : liquid at room temp one or more double bonds between carbons in the fatty acids allows for “kinks” in the tails most plant fats Saturated fats: have only single C-C bonds in fatty acid tails solid at room temp most animal fats

Saturated fatty acid

Unsaturated fatty acid

2. STRUCTURE OF TRIGLYCERIDES Glycerol + 3 fatty acids 3 ester linkages are formed between a hydroxyl group of the glycerol and a carboxyl group of the fatty acid.

3. PHOSPHOLIPIDS Structure: Glycerol + 2 fatty acids + phosphate group. Function: Main structural component of membranes, where they arrange in bilayers.

PHOSPHOLIPIDS IN WATER

4. WAXES Function: Lipids that serve as coatings for plant parts and as animal coverings.

5. STEROIDS Structure: Four carbon rings with no fatty acid tails Functions: Component of animal cell membranes Modified to form sex hormones

C. PROTEINS Structure: Polypeptide chains Consist of peptide bonds between 20 possible amino acid monomers Have a 3 dimensional globular shape

1. FUNCTIONS OF PROTEINS Enzymes which accelerate specific chemical reactions up to 10 billion times faster than they would spontaneously occur. Structural materials, including keratin (the protein found in hair and nails) and collagen (the protein found in connective tissue).

Specific binding, such as antibodies that bind specifically to foreign substances to identify them to the body's immune system. Specific carriers, including membrane transport proteins that move substances across cell membranes, and blood proteins, such as hemoglobin, that carry oxygen, iron, and other substances through the body.

Contraction, such as actin and myosin fibers that interact in muscle tissue. Signaling, including hormones such as insulin that regulate sugar levels in blood.

2. STRUCTURE OF AMINO ACID MONOMERS Consist of an asymmetric carbon covalently bonded to: Hydrogen Amino group Carboxyl (acid) group Variable R group specific to each amino acid.

PROPERTIES OF AMINO ACIDS Grouped by polarity Variable R groups (side chains) confer different properties to each amino acid: polar, water soluble. non-polar, water insoluble positively charged negatively charged.

4 levels of protein structure: primary secondary tertiary quaternary

3. PRIMARY STRUCTURE Unique sequence of amino acids in a protein Slight change in primary structure can alter function Determined by genes Condensation synthesis reactions form the peptide bonds between amino acids

4. SECONDARY STRUCTURE Repeated folding of protein’s polypeptide backbone stabilized by H bonds between peptide linkages in the protein’s backbone 2 types, alpha helix, beta pleated sheets

5. TERTIARY STRUCTURE Irregular contortions of a protein due to bonding between R groups Weak bonds: H bonding between polar side chains ionic bonding between charged side chains hydrophobic and van der Waals interactions Strong bonds: disulfide bridges form strong covalent linkages

5. QUATERNARY STRUCTURE Results from interactions among 2 or more polypeptides

FACTORS THAT DETERMINE PROTEIN CONFORMATION Occurs during protein synthesis within cell Depends on physical conditions of environment pH, temperature, salinity, etc. Change in environment may lead to denaturation of protein Denatured protein is biologically inactive Can renature if primary structure is not lost

D. NUCLEIC ACIDS Two kinds: DNA: double stranded can self replicate makes up genes which code for proteins is passed from one generation to another RNA: single stranded functions in actual synthesis of proteins coded for by DNA is made from the DNA template molecule

1. NUCLEOTIDE MONOMER STRUCTURE Both DNA and RNA are composed of nucleotide monomers. Nucleotide = 5 carbon sugar, phosphate, and nitrogenous base Deoxyribose in DNARibose in RNA

2. BUILDING THE POLYMER Phosphate group of one nucleotide forms strong covalent bond with the #3 carbon of the sugar of the other nucleotide.

3. FUNCTIONS OF NUCLEOTIDES Monomers for Nucleic Acids Transfer chemical energy from one molecule to another (e.g. ATP)

DNA: Double helix 2 polynucleotide chains wound into the double helix Base pairing between chains with H bonds A - T C - G

Summary of the Organic Molecules: