The Chemical Basis of The Chemical Basis of LifeLife

Organic CompoundsOrganic Compounds

Compounds containing carbonCompounds containing carbon (Actually contain carbon, hydrogen, and (Actually contain carbon, hydrogen, and

oxygen) oxygen) Compounds that come from living thingsCompounds that come from living things

Q1)Give two examples of Q1)Give two examples of organic compounds?organic compounds?

Sugar, StarchSugar, Starch

Inorganic compoundsInorganic compounds

Don’t contain carbonDon’t contain carbon Don’t come from living thingsDon’t come from living things Exceptions: Carbon dioxide, Carbon Exceptions: Carbon dioxide, Carbon

monoxidemonoxide

Q2) Give 2 examples of inorganic Q2) Give 2 examples of inorganic moleculesmolecules

Water, SaltWater, Salt

Unique bonding properties of Unique bonding properties of carboncarbon

Carbon has four electrons in its outer shellCarbon has four electrons in its outer shell Carbon can form 4 covalent bondsCarbon can form 4 covalent bonds Carbon can form complex molecules because of Carbon can form complex molecules because of

its ability to form 4 bonds at the same timeits ability to form 4 bonds at the same time

Chemistry of carbonChemistry of carbon

Carbon can form Carbon can form Single covalent bondsSingle covalent bonds

• Shares 1 electron with one other atom.Shares 1 electron with one other atom. Double covalent bonds Double covalent bonds

• Shares 2 electrons with one other atomShares 2 electrons with one other atom Triple covalent bonds (rare)Triple covalent bonds (rare)

• Shares 3 electrons with one other atomShares 3 electrons with one other atom(See examples of these bonds on the bottom of (See examples of these bonds on the bottom of page 49)page 49)

Functional groupsFunctional groups

Common parts used Common parts used molecule buildingmolecule building HydroxylHydroxyl

• -OH-OH

Carboxyl Carboxyl • -COOH-COOH

AminoAmino• -NH-NH22

MonomersMonomers

Simple building block moleculesSimple building block molecules

PolymersPolymers

Two or more monomers covalently bonded Two or more monomers covalently bonded together.together.

Can be two or two thousand…Can be two or two thousand… Allow very large molecules to built with Allow very large molecules to built with

only a few basic parts. only a few basic parts.

Two chemical reactions used Two chemical reactions used

Dehydration SynthesisDehydration Synthesis Covalent bond is formed by the removal of Covalent bond is formed by the removal of

water.water. Two monomers become joined together.Two monomers become joined together.

Dehydration Synthesis ReactionDehydration Synthesis Reaction

Two Chemical Reactions UsedTwo Chemical Reactions Used

HydrolysisHydrolysis Separation of two monomers by adding water Separation of two monomers by adding water

and breaking the covalent bondand breaking the covalent bond

Hydrolysis ReactionHydrolysis Reaction

CarbohydratesCarbohydrates

Made from glucose molecules (sugars)Made from glucose molecules (sugars) Carbohydrates are used by living things as Carbohydrates are used by living things as

a source of energy.a source of energy.

MonosaccharidesMonosaccharides

Simple sugarsSimple sugars Mono = one Saccharide = sugarMono = one Saccharide = sugar

Have the formula CHave the formula C66HH1212OO66

Form rings when in waterForm rings when in water

Some Sample Some Sample MonosaccharidesMonosaccharides

Q2) Where do people get Q2) Where do people get glucose molecules?glucose molecules?

Plants produce glucose during Plants produce glucose during photosynthesis and animals get glucose photosynthesis and animals get glucose by eating plants.by eating plants.

DisaccharidesDisaccharides

Di = Two Saccharide = sugarDi = Two Saccharide = sugar

PolysaccharidesPolysaccharides

Two or more monosaccharides joined Two or more monosaccharides joined together by a covalent bond.together by a covalent bond.

The bond forms by a Dehydration The bond forms by a Dehydration Synthesis Reaction.Synthesis Reaction.

Four types of polysaccharides Four types of polysaccharides Made of GlucoseMade of Glucose

StarchStarch

Energy storage in plantsEnergy storage in plants

GlycogenGlycogen

Energy storage in plant seeds and short term Energy storage in plant seeds and short term energy storage in animals (1 day)energy storage in animals (1 day)

CelluloseCellulose Structural support in plantsStructural support in plants

Starch Vs. CelluloseStarch Vs. Cellulose

STARCHSTARCH

CELLULOSECELLULOSE

ChitinChitin

Used in insect exoskeletons for structural Used in insect exoskeletons for structural supportsupport

Harvested and used as surgical stitchesHarvested and used as surgical stitches

LipidsLipids

Fats Fats Oils Oils WaxesWaxes

Do not dissolve in water!!!Do not dissolve in water!!!

Molecules made from lipidsMolecules made from lipids

FatsFats Energy storage in animals and plant seedsEnergy storage in animals and plant seeds

• A gram of fat stores more than twice as much A gram of fat stores more than twice as much energy as a gram of a polysaccharide.energy as a gram of a polysaccharide.

PhospholipidsPhospholipids Used in cell membranes Used in cell membranes

Separations between inside and outside of cellSeparations between inside and outside of cell

WaxesWaxes

Water proof molecules, many usesWater proof molecules, many uses Example: Waxy coating on leaves Example: Waxy coating on leaves

prevents water lossprevents water loss

Chemistry of Fats Chemistry of Fats

Glycerol Glycerol  3 fatty acids3 fatty acids

Chains of carbons with a carboxyl (acid) Chains of carbons with a carboxyl (acid) group at one end of each fatty acidgroup at one end of each fatty acid

Two major types of fatsTwo major types of fats Saturated fats – single bonds between Saturated fats – single bonds between

carbon atomscarbon atoms Unsaturated fats – double bonds between Unsaturated fats – double bonds between

carbon atomscarbon atoms

Q3) Which type of fat is Q3) Which type of fat is unhealthy?unhealthy?

Saturated fatsSaturated fats

What is the difference between fats What is the difference between fats and oils?and oils?

Fats are solid at room temperature and Fats are solid at room temperature and oils are liquids at room temperature.oils are liquids at room temperature.

ProteinsProteins

The molecules that do The molecules that do the work inside of the the work inside of the cell.cell.

Proteins are Proteins are responsible for most responsible for most of what happens of what happens inside of the cell.inside of the cell.

Functions of a proteinFunctions of a protein

MovementMovement Structural support  Structural support   StorageStorage DefenseDefense Regulation of chemical processesRegulation of chemical processes

What are two examples of What are two examples of things made of protein?things made of protein?

Enzymes (thousands of different types)Enzymes (thousands of different types) Speed up chemical reactionsSpeed up chemical reactions

HemoglobinHemoglobin Used in red blood cells to transport oxygenUsed in red blood cells to transport oxygen

Structure of proteinStructure of protein

Amino acidAmino acid The monomer of The monomer of

proteinsproteins There are 20 different There are 20 different

amino acidsamino acids They can make billions They can make billions

of different proteinsof different proteins

Peptide BondPeptide Bond

Holds these monomers together.Holds these monomers together. Formed by a dehydration synthesis Formed by a dehydration synthesis

reactionreaction

PolypeptidesPolypeptides

Many amino acids Many amino acids bonded together bonded together making a long chainmaking a long chain

How proteins are formedHow proteins are formed

Proteins are complexly folded polypeptide Proteins are complexly folded polypeptide chainschains

There are four levels of protein structure There are four levels of protein structure Each level of folding makes the protein Each level of folding makes the protein

more complex.more complex.

One change can be devastatingOne change can be devastating

Stop for today.Stop for today.

The function of enzymesThe function of enzymes

Enzymes are Protein CatalystsEnzymes are Protein Catalysts Increase the speed of chemical Increase the speed of chemical

reactions without being used up themselves.reactions without being used up themselves. NOT CHANGED BY REACTIONNOT CHANGED BY REACTION

  

SubstratesSubstrates

The molecule that binds to the enzymeThe molecule that binds to the enzyme These are the ones changed in the These are the ones changed in the

reactionreaction

Enzyme-substrate complexEnzyme-substrate complex  

Active siteActive site The space where the substrate fitsThe space where the substrate fits

Lock and keyLock and key Each enzyme is specific for one substrate!! Each enzyme is specific for one substrate!! 

Activation EnergyActivation Energy

Energy needed to get a reaction Energy needed to get a reaction started.started.

Bonds are weakened by activation energy

New bonds form to make products

Activation EnergyActivation Energy

Enzymes lower a reaction’s activation Enzymes lower a reaction’s activation energyenergy

A lower activation energy makes a A lower activation energy makes a reaction happen fasterreaction happen faster

EnzymesEnzymes

Catalysts in the body are enzymesCatalysts in the body are enzymes Enzymes work best at a certain Enzymes work best at a certain

temperature and pHtemperature and pH

If the temperature or pH changes, If the temperature or pH changes, the enzyme may not function.the enzyme may not function.

If the bonds that hold the enzyme’s shape If the bonds that hold the enzyme’s shape are changed, the enzyme will come apart.are changed, the enzyme will come apart.

If this happens, the enzyme will If this happens, the enzyme will denature.denature.

Nucleic AcidsNucleic Acids

Polymers which are used to store genetic Polymers which are used to store genetic information information 

NucleotideNucleotide

Monomer of nucleic acidsMonomer of nucleic acids Made from Made from

• 1 sugar1 sugar• 1 base 1 base • 1 phosphate1 phosphate

  

Two types of nucleic acids and Two types of nucleic acids and their uses:their uses:

Deoxyribonucleic AcidDeoxyribonucleic Acid DNADNA Stores genetic information and passes it on to Stores genetic information and passes it on to

the next generationthe next generation Ribonucleic AcidRibonucleic Acid

RNARNA Takes information and uses it to make Takes information and uses it to make

proteinsproteins

The information is stored in The information is stored in basesbases

The differences in the nucleotides is in the The differences in the nucleotides is in the bases.bases.

The order of these bases makes up the The order of these bases makes up the genetic CODE.genetic CODE.

DNA BasesDNA Bases

There are four bases used in DNAThere are four bases used in DNACytosine (C), Thymine (T)Cytosine (C), Thymine (T)Adenine (A), Guanine (G)Adenine (A), Guanine (G)

RNA BasesRNA Bases

There are four bases used in RNAThere are four bases used in RNA Cytosine (C), Uracil (U)Cytosine (C), Uracil (U) Adenine (A), Guanine (G)Adenine (A), Guanine (G)

Thymine is replaced by Uracil in RNA