Cell Unit Lecture Cell Unit Lecture VV

Enzymes and Enzymes and MacromoleculesMacromolecules

Biology Standards Biology Standards CoveredCovered

1b ~ students know 1b ~ students know enzymes are proteinsenzymes are proteins that that catalyzecatalyze biochemical reactions biochemical reactions without altering the reaction equilibrium without altering the reaction equilibrium and the and the activities of enzymesactivities of enzymes depend ondepend on temperature, ionic conditionstemperature, ionic conditions, and the , and the pHpH of the surroundingsof the surroundings

1h ~ students know 1h ~ students know mostmost macromolecules macromolecules (polysaccharides, nucleic acids, proteins, (polysaccharides, nucleic acids, proteins, and lipids) in cells and organisms are and lipids) in cells and organisms are synthesized from a small collection of synthesized from a small collection of simple precursors (monomers & simple precursors (monomers & polymers)polymers)

Standards Standards translatedtranslated

1b ~ an enzyme is a specialized 1b ~ an enzyme is a specialized protein that makes a reaction happen protein that makes a reaction happen or increases the rate of a reaction. or increases the rate of a reaction. Enzymes are affected by pH (acidity), Enzymes are affected by pH (acidity), temperature, and salty conditions.temperature, and salty conditions.

1h ~ Most macromolecules 1h ~ Most macromolecules (polymers) are (polymers) are made in cellsmade in cells from a from a small collection of simple molecules small collection of simple molecules (monomers)(monomers) This is like a Lego house (polymer) made This is like a Lego house (polymer) made

up of individual Legos (monomers)up of individual Legos (monomers)

Carbon Based MoleculesCarbon Based Molecules All living things are made up of a collection All living things are made up of a collection

of atoms and molecules that work together of atoms and molecules that work together to support lifeto support life

Nearly Nearly allall living things on planet Earth are living things on planet Earth are supported by one atom, an atom of supported by one atom, an atom of CarbonCarbon

There are There are FourFour primary primary Carbon Based Carbon Based MoleculesMolecules supporting all life on our supporting all life on our planet:planet: Carbohydrates ~ sugarsCarbohydrates ~ sugars Lipids ~ fatsLipids ~ fats Proteins ~ amino acid chain (polypeptide)Proteins ~ amino acid chain (polypeptide) Nucleic acids ~ DNA, RNA, & ATPNucleic acids ~ DNA, RNA, & ATP

Carbon Based MoleculesCarbon Based Molecules CarbonCarbon is the is the mostmost

important element important element in living systemsin living systems It has:It has:

6 Protons6 Protons 6 electrons6 electrons 6 Neutrons6 Neutrons Mass of 12.011 amuMass of 12.011 amu

It It bonds in four bonds in four directionsdirections and can and can form form double bondsdouble bonds

Carbon Based MoleculesCarbon Based Molecules Carbon based molecules Carbon based molecules

can be small and they can can be small and they can be very large. be very large.

The smallest are called The smallest are called monomersmonomers and usually and usually consist of one carbon ring consist of one carbon ring or moleculeor molecule

Larger carbon based Larger carbon based molecules are made up of molecules are made up of many monomers to form a many monomers to form a polymerpolymer Mono = oneMono = one Poly = manyPoly = many

Carbon Based MoleculesCarbon Based Molecules CarbohydratesCarbohydrates as carbon based as carbon based

moleculesmolecules Also known as “sugars”Also known as “sugars” Made up of three elementsMade up of three elements

CarbonCarbon HydrogenHydrogen OxygenOxygen

A couple of the simplest carbohydrates A couple of the simplest carbohydrates are are fructosefructose and and glucoseglucose These are single carbon ring molecules that These are single carbon ring molecules that

provide energy for cellular respirationprovide energy for cellular respiration

CarbohydratesCarbohydrates can can be a simple sugar be a simple sugar like Glucose or many like Glucose or many Glucose monomers Glucose monomers linked togetherlinked together

A A DisaccharideDisaccharide is a is a sugar that has sugar that has twotwo Glucose monomers Glucose monomers The most common The most common

disaccharide is disaccharide is sucrosesucrose

Carbon Based MoleculesCarbon Based Molecules

PolysaccharidesPolysaccharides are are manymany Glucose monomers Glucose monomers linked togetherlinked together

StarchStarch ~ a polysaccharide ~ a polysaccharide sugar made by plants to store sugar made by plants to store energyenergy

CelluloseCellulose ~ a polysaccharide ~ a polysaccharide made by plants to form cell made by plants to form cell wallswalls

GlycogenGlycogen ~ a polysaccharide ~ a polysaccharide made by animals to store made by animals to store sugar for energy (usually in sugar for energy (usually in the liver)the liver)

Carbon Based MoleculesCarbon Based Molecules

Good Carbs & Bad Good Carbs & Bad CarbsCarbs

LipidsLipids are an important are an important carbon based molecule that carbon based molecule that can be broken down into can be broken down into energy for the cell energy for the cell andand function as part of the cell’s function as part of the cell’s structurestructure

They include They include fats, oils, and fats, oils, and cholesterolcholesterol

They are They are non-polarnon-polar and repel and repel polar substances like waterpolar substances like water

Carbon Based MoleculesCarbon Based Molecules

A A phospholipidphospholipid having a having a phosphate head and two phosphate head and two fatty-acid tailsfatty-acid tails is a is a monomermonomer of the of the polymerpolymer known as the known as the cell cell membranemembrane

The The phosphate headphosphate head of of the phospholipid attracts the phospholipid attracts water because it is polar water because it is polar while the fatty-acid tails while the fatty-acid tails repel it as it passes repel it as it passes through the membranethrough the membrane

Carbon Based MoleculesCarbon Based Molecules

Lipids store a huge Lipids store a huge amount of energy in amount of energy in their fatty-acid tailstheir fatty-acid tails

A lipid is A lipid is saturatedsaturated if the if the Carbon chain is Carbon chain is loadedloaded with Hydrogen atoms with Hydrogen atoms

A lipid is A lipid is unsaturatedunsaturated if if there are a few or more there are a few or more double bonds between double bonds between Carbons making it Carbons making it “kink”“kink”

Carbon Based MoleculesCarbon Based Molecules

ProteinsProteins are another are another important carbon-based important carbon-based molecule made up of molecule made up of several dozen to several dozen to thousands of thousands of amino amino acidsacids

An An amino acid chainamino acid chain is is also known as a also known as a polypeptide chainpolypeptide chain because of its because of its manymany peptide bonds holding the peptide bonds holding the amino acids togetheramino acids together

Carbon Based MoleculesCarbon Based Molecules

Each amino acid is made Each amino acid is made up of the same functional up of the same functional groups except for one groups except for one R – R – GroupGroup Amino groupAmino group Carboxyl groupCarboxyl group Hydrogen & base CarbonHydrogen & base Carbon UniqueUnique R GroupR Group

Amino acids are monomers Amino acids are monomers while a protein is the while a protein is the polymerpolymer

Carbon Based MoleculesCarbon Based Molecules

Nucleic acidsNucleic acids are the are the fourth Carbon based fourth Carbon based moleculemolecule

They are all made up of They are all made up of monomers called monomers called nucleotidesnucleotides

DNA, RNA, and ATP are DNA, RNA, and ATP are nucleic acids that are found nucleic acids that are found in all living organismsin all living organisms ATP pictured here has 3 ATP pictured here has 3

phosphates bonded to a 5-phosphates bonded to a 5-Carbon sugar and a Nitrogen Carbon sugar and a Nitrogen basebase

Carbon Based MoleculesCarbon Based Molecules

Carbon Based MoleculesCarbon Based Molecules

Enzymes the Enzymes the specialspecial proteinprotein

An An enzymeenzyme is a protein polymer that is made is a protein polymer that is made up of many amino acid monomersup of many amino acid monomers

Cells use enzymes to Cells use enzymes to catalyzecatalyze biochemical biochemical reactionsreactions To “make them happen”To “make them happen” To “speed up reactions”To “speed up reactions”

An enzyme has a unique 3-dimensional shape An enzyme has a unique 3-dimensional shape that that defines the role/job that it performsdefines the role/job that it performs

An enzymes shape is maintained by being in An enzymes shape is maintained by being in the right the right temperature, pH (acidity), and temperature, pH (acidity), and ionic conditionsionic conditions

Chemical ReactionsChemical ReactionsReactants Reactants Products Products

Water + Carbon Dioxide Water + Carbon Dioxide Glucose + Oxygen Glucose + Oxygen + Water+ Water

Activation energyActivation energy is the “energy is the “energy required to required to startstart a chemical reaction” a chemical reaction” Think of pushing a ball to the top of a small Think of pushing a ball to the top of a small

hill so that it can roll down a very steep slope hill so that it can roll down a very steep slope on the other sideon the other side

The energy it took to push the ball to the top The energy it took to push the ball to the top of the hill is the of the hill is the activation energyactivation energy

Enzymes often Enzymes often lowerlower activation energies activation energies

Enzymes the Enzymes the specialspecial proteinprotein

When enzymes When enzymes are present, the are present, the breakdown of breakdown of Glucose happens Glucose happens easier easier

Enzymes the Enzymes the specialspecial proteinprotein

pH is the “percent pH is the “percent Hydrogen” of a Hydrogen” of a solutionsolution Also known as “acidity”Also known as “acidity”

The scale is based on The scale is based on Powers of 10 and goes Powers of 10 and goes from 0 from 0 14 with 14 with Zero being the MOST Zero being the MOST AcidicAcidic and and 14 being 14 being the MOST Basicthe MOST Basic

Enzymes the Enzymes the specialspecial proteinprotein

An enzyme protein An enzyme protein has an has an active siteactive site where a where a substratesubstrate molecule attaches molecule attaches

This makes it This makes it possible for a possible for a chemical reaction chemical reaction to occur and the to occur and the enzyme acts as a enzyme acts as a catalystcatalyst

Enzymes the Enzymes the specialspecial proteinprotein

Enzymes are Enzymes are often referred often referred to as having a to as having a “lock and key” “lock and key” modelmodel

Enzymes are Enzymes are affected by affected by temperature temperature and as temp. and as temp. increases, increases, enzyme activity enzyme activity increasesincreases

Enzymes the Enzymes the specialspecial proteinprotein