The Chemistry of Life What are living creatures

The Chemistry of Life What are living creatures made of? Why do we have to eat?

ORGANIC CHEMISTRY

Organic Chemistry � Definition… The branch of chemistry that studies carbon and its compounds

Elements of Life § 96% of living organisms is made of: n n carbon (C) oxygen (O) hydrogen (H) nitrogen (N) Regents Biology

Organic compound A compound that contains carbon and hydrogen bonded together. Example: glucose—C 6 H 12 O 6

Inorganic compound A compound that does not contain carbon Example: H 2 O Na. Cl

All organisms are organic. In other words, all organisms are carbon based.

Molecules of Life § Put C, H, O, N together in different § ways to build living organisms What are bodies made of? u carbohydrates § sugars & starches proteins u fats (lipids) u nucleic acids u § DNA, RNA Regents Biology

The Major Organic Compounds • Carbohydrates • Lipids • Proteins • Nucleic Acids large Macromolecules— very large molecules

Don’t forget water § Water 65% of your body is H 2 O u water is inorganic u § doesn’t contain carbon § Rest of you is made of carbon molecules u organic molecules § § Regents Biology carbohydrates proteins fats nucleic acids

Why do we eat? § We eat to take in more of these chemicals u Food for building materials § to make more of us (cells) § for growth § for repair u Food to make energy § calories § to make ATP Regents Biology ATP

Vocabulary woohoo! 1. polymer— a molecule made of many repeating smaller molecules 2. monomer— each one of the repeating smaller molecules

Building large organic molecules § Small molecules = monomers (building block) § Bond them together = polymers Regents Biology

Macromolecules and basic units Macromolecule Basic unit Carbohydrate Monosaccaride Protein Amino acid Lipid Fatty acid Nucleic acid Nucleotide

Building important polymers Carbohydrates = built from sugars sugar – sugar – sugar Proteins = built from amino acids amino amino acid – acid – acid Nucleic acids (DNA) = built from nucleotides nucleotide – nucleotide Regents Biology

THE CARBOHYDRATES

ELEMENTS FOUND IN CARBOHYDRATES • CARBON (C) • HYDROGEN (H) • OXYGEN (O)

The carbohydrates include… 1 • Monosaccharides one sugar molecule 2 • Disaccharides two sugar molecule many • Polysaccharides many sugar molecule Saccharide means “sugar”

The Monosaccharides • One sugar molecules • Recognized by their carbon ring

THESE ARE MONOSACCHARIDES Check out their carbon rings Glucose C 6 H 12 O 6 Galactose C 6 H 12 O 6 Fructose C 6 H 12 O 6 What makes these three molecules different from each other? The arrangement of their atoms

Compounds with the same molecular formula but different structures are called ISOMERS

The Disaccharides • Two sugar molecule • Two monosaccharides bonded together covalent bond holding them together monosac

Example of a Disaccharide Two monosaccharides bonded together

These are disaccharides • Maltose (glucose + glucose) • Sucrose (glucose + fructose) • Lactose (glucose + galactose)

• Monosaccharides and disaccharides are called simple sugars • What do you notice about the names of all the simple sugars? ─OSE = SUGAR

The Polysaccharides • Many sugar molecules bonded together by covalent bonds … etc.

These are polysaccharides • Starch • Glycogen • Cellulose • Chitin All made of repeating glucose molecules

Starch is a polysaccharide • Chain of glucose molecules • The form in which plants store food • So … starch is found only in plant products üPotatoes üRice üBread üCorn üPasta üetc.

Glycogen is a polysaccharide • Chain of glucose molecules • The form in which many animals, including humans, store food • In what organ do humans store glycogen? THE LIVER!

Cellulose is a polysaccharide • Chain of glucose molecules • Found in cell walls What kind of cells have a cell wall made of cellulose? Plant • Cellulose is what we commonly call dietary fiber or roughage

Chitin is a polysaccharide outside • Found in exoskeletons

Why do organisms need carbohydrates? SIMPLE SUGARS • Immediate energy— Are broken down during cellular respiration STARCH AND GLYCOGEN • Stored energy— Can be converted back into glucose when needed CELLULOSE AND CHITIN • Structure and Support— Gives shape and protection to plant cells Protects soft tissues of some animals

Carbohydrates: Food Sources • Simple carbs (simple • Complex carbs (like sugars) are found in starches) are found in most candy and sweet pasta, bread, drinks, fruit, potatoes, legumes & vegetables, and milk. corn. They take longer They are quickly to digest, and provide digested and give a energy longer. short burst of energy.

Carbohydrates: Function • Provide body with energy! Complex carb (ex. Starch) – What should you eat before playing the big game? Candy bar or pasta? • Candy bar: contains simple sugars, provides a short burst of energy • Pasta: contains starch which takes longer to break down, provides longer-lasting energy – *We can’t digest celluloseit is used as fiber, or roughage instead. Broken down to disaccharides Broken down further • Ex. : corn Simple sugars (ex. Glucose)

Carbohydrates: Indicator Tests • Simple Sugars: – Benedict’s solution – Blue solution turns orange/green/brown • Complex Carbs: – Lugol’s solution/Iodine – Turns from orange-red -brown to black-purple

Let’s Summarize Carbohydrates: 1. Monosaccharides – Glucose, galactose, fructose 2. Disaccharides – Maltose – Sucrose – Lactose 3. Polysaccharides – Starch – Glycogen – Cellulose – Chitin