Chemistry of Living Systems

Chemistry of Chemistry of Living SystemsLiving Systems

Chemistry of AtomsChemistry of Atoms

AtomAtom: smallest unit of : smallest unit of matter matter

Three components of Three components of an atom are…an atom are…

Electrons -1 Electrons -1

Protons +1 Protons +1

Neutrons 0Neutrons 0

Found outside the nucleusFound outside the nucleus

Found in the nucleusFound in the nucleus

Found in the nucleusFound in the nucleus

Ions=Different # of

p+ and e-

ISOTOPES=Same # of p+ and e-

Different # ofn0

Atomic Weight =

p+ + n0

Atomic Number=# of Protons

11Na

ATOMSATOMS

Count the electrons!Count the electrons!

# of electrons in the outer shell are clues!# of electrons in the outer shell are clues!Greater than 4 in the outer shell will take Greater than 4 in the outer shell will take

from other atomsfrom other atomsLess than 4 in the outer shell will give to Less than 4 in the outer shell will give to

other atomsother atomsProvides hints on how and what types of Provides hints on how and what types of

bonds formbonds form

Elements Essential to LifeElements Essential to Life

About 25 elements are essential to About 25 elements are essential to living organismsliving organisms

CHNOPS: Make up 97% of CHNOPS: Make up 97% of living matterliving matter

Natural Elements in the Human BodyELEMENTS ATOMIC #ATOMIC # % in HUMANS% in HUMANS

Oxygen (O) 88 65.065.0

Carbon (C)Carbon (C) 66 18.518.5

Hydrogen (H)Hydrogen (H) 11 9.59.5

Nitrogen (N)Nitrogen (N) 77 3.33.3

Calcium (Ca)Calcium (Ca) 2020 1.51.5

Phosphorus (P)Phosphorus (P) 1515 1.01.0

Potassium (K)Potassium (K) 1919 0.40.4

Sulfur (S)Sulfur (S) 1616 0.30.3

Sodium (Na)Sodium (Na) 1111 0.20.2

Magnesium (Mg)Magnesium (Mg) 1212 0.20.2

Chlorine (Cl)Chlorine (Cl) 1717 0.10.1

Chemical BondsChemical BondsChemical Bonds are the attractive force Chemical Bonds are the attractive force

that hold atoms together in a moleculethat hold atoms together in a molecule

Bonds form when electrons are shared Bonds form when electrons are shared OR transferred between atomsOR transferred between atoms

Covalent bondsCovalent bonds – sharing electrons (“co-” – sharing electrons (“co-” means to share as in cooperate)means to share as in cooperate)

Ionic BondsIonic Bonds – give and take electrons – give and take electrons Hydrogen BondsHydrogen Bonds – weak attractions between – weak attractions between

molecules molecules

Stronger atoms try to “steal” the H’s Stronger atoms try to “steal” the H’s electron, electron, but it keeps a tiny hold on it.but it keeps a tiny hold on it.

Nonpolar Covalent BondsNonpolar Covalent Bonds

Electrons are Electrons are shared shared equallyequally

Polar Covalent BondsPolar Covalent Bonds

Share electrons as Share electrons as in other covalent in other covalent bonds, but the bonds, but the nucleus of one nucleus of one atom attracts the atom attracts the electrons more electrons more strongly so it is not strongly so it is not equal.equal.

Ionic BondingIonic Bonding

One atom gets extra electron(s) (becomes One atom gets extra electron(s) (becomes a negative ion) and one gives extra a negative ion) and one gives extra electron(s) (becomes a positive ion) the electron(s) (becomes a positive ion) the two ions attract each other.two ions attract each other.

CARBONCARBON

Why is carbon so important in Why is carbon so important in biological molecules?biological molecules?

Carbon is easy to synthesize (break down Carbon is easy to synthesize (break down and be used).and be used).

Molecules with carbon are called Molecules with carbon are called ORGANICORGANIC

Molecules without carbon are called Molecules without carbon are called INORGANICINORGANIC

What are the What are the important important

molecules of life?molecules of life?

The Structure of WaterThe Structure of Water

““V” shaped molecule V” shaped molecule

Unequal sharing of Unequal sharing of electrons causes oxygen electrons causes oxygen to have a slightly to have a slightly negative chargenegative charge

called a called a polar moleculepolar molecule

Properties of WaterProperties of Water

CohesionCohesion is the is the tendency of tendency of molecules of the molecules of the same kind to stick same kind to stick to one another.to one another.

Water has stronger Water has stronger cohesion than most cohesion than most liquidsliquids

Water molecules are Water molecules are also attracted to also attracted to certain other certain other moleculesmolecules

Attraction between Attraction between unlike molecules is unlike molecules is called called adhesionadhesion

Cohesion pulls molecules at Cohesion pulls molecules at the surface tightly together, the surface tightly together, forming a film-like boundaryforming a film-like boundary

This is This is surface tensionsurface tension

CarbohydratesCarbohydrates(C,H, and O molecules in a ratio of 1:2:1)(C,H, and O molecules in a ratio of 1:2:1)

Carbohydrates Carbohydrates are an are an

important important energy source energy source

for cells.for cells.

TYPES OF CARBOHYDRATESTYPES OF CARBOHYDRATES

Monosaccharide – simple sugars made of Monosaccharide – simple sugars made of one sugar molecule. (ex. Glucose)one sugar molecule. (ex. Glucose)


Disaccharides – (ex. Sucrose) Disaccharides – (ex. Sucrose)

2 monosaccharides linked 2 monosaccharides linked togethertogether

Polysaccharides – ex. Starch, Cellulose)Polysaccharides – ex. Starch, Cellulose)More than two sugars linked together.More than two sugars linked together.


Did you notice how the Did you notice how the sugars all sound the sugars all sound the

same?same?They all end in “-ose” (-ose = They all end in “-ose” (-ose =

sugar)sugar)

Ex. Sucrose, Glucose, Fructose, Ex. Sucrose, Glucose, Fructose, LactoseLactose


Simple Carbs ~ mono and disaccahridesSimple Carbs ~ mono and disaccahridesComplex carbs ~ starches, polysaccharidesComplex carbs ~ starches, polysaccharides

LIPIDSLIPIDSMade up of two parts:Made up of two parts:

A head (it is hydrophillic)A head (it is hydrophillic) A tail made of a A tail made of a

hydrocarbon chain (it is hydrocarbon chain (it is hydrophobic). hydrophobic).

This lets the lipids form This lets the lipids form bilayers creating waterproof bilayers creating waterproof barriers like in a cell’s barriers like in a cell’s membrane.membrane.

LIPIDSLIPIDSFatty acids, waxes, fats, steroids Fatty acids, waxes, fats, steroids

and oils are formed by lipids (all and oils are formed by lipids (all are are insoluble in waterinsoluble in water))

ProteinsProteinsMolecules made up of Molecules made up of

one or more chains of one or more chains of amino acids. They amino acids. They are used for many are used for many

functions…functions…

Proteins are used for…Proteins are used for…

Structure – they make Structure – they make collagen in skin and collagen in skin and keratin in hair/nails/hornkeratin in hair/nails/horn


Movement ~ Movement ~ actin and actin and myosin in myosin in muscle muscle stimulate the stimulate the muscle to movemuscle to move


Defense Defense ~~ antibodies antibodies in in bloodstreambloodstream


StorageStorage ~ ~

corn seeds corn seeds are are predominately predominately made of made of proteinprotein


SignalsSignals ~ ~ growth growth hormones in hormones in your blood your blood streamstream


Nucleic AcidsNucleic Acids (used in (used in DNA or RNA) – long DNA or RNA) – long chains of pieces called chains of pieces called nucleotides. A nucleotide nucleotides. A nucleotide has 3 parts…has 3 parts…1. five carbon sugar (ribose 1. five carbon sugar (ribose

or deoxyribose)or deoxyribose)

2. phosphate group2. phosphate group

3. Nitrogen base (A,T,C or G)3. Nitrogen base (A,T,C or G)


CatalysisCatalysis ~ ~ enzymes which enzymes which speed up processes in the bodyspeed up processes in the body

So what is an So what is an Enzyme?Enzyme?

An enzyme is used to An enzyme is used to speed things up or help speed things up or help

break things down in break things down in your body.your body.

Words You Should KnowWords You Should Know

Enzyme (E)Enzyme (E): protein catalyst: protein catalyst

CatalystsCatalysts: speed up reactions without : speed up reactions without being changed by the reactionbeing changed by the reaction

Substrate (S)Substrate (S): reactant(s) in the : reactant(s) in the enzyme-catalyzed reactionenzyme-catalyzed reaction

Active siteActive site: area of enzyme where : area of enzyme where substrate(s) bind(s)substrate(s) bind(s)

EnzymesEnzymes

Enzymes are proteins with a SPECIFIC Enzymes are proteins with a SPECIFIC SHAPESHAPE

The active site is a part of the protein The active site is a part of the protein which recognizes and binds to the which recognizes and binds to the substratesubstrate

CofactorsCofactors (e.g. Zn 2+, Cu 2+, B vitamins) (e.g. Zn 2+, Cu 2+, B vitamins) some enzymes won’t hook-up to a some enzymes won’t hook-up to a substrates without thesesubstrates without these

SpecificitySpecificity

‘‘Lock and Key Model’Lock and Key Model’ – says there is a perfect – says there is a perfect fit between active site and substratefit between active site and substrate

Modified to Modified to ‘Induced Fit Model’‘Induced Fit Model’ - active site can - active site can expand or contract to “fit” the substrate shapeexpand or contract to “fit” the substrate shape

The induced fit model allows for small The induced fit model allows for small differences (possibility of letting several differences (possibility of letting several different kinds of substrates hook up)different kinds of substrates hook up)

How do enzymes speed up reactions?How do enzymes speed up reactions?

Enzymes lower the Enzymes lower the activation energyactivation energy

(E(EAA=amount of energy that =amount of energy that

reactant molecules require reactant molecules require to start a reaction)to start a reaction)

EnzymesEnzymes

Are involved in every biochemical reaction Are involved in every biochemical reaction and thereby control metabolismand thereby control metabolism

Are named according to the reaction that Are named according to the reaction that they facilitatethey facilitateExamples: Examples: SucraseSucrase breaks down sucrose breaks down sucrose into glucose and fructoseinto glucose and fructoseDNA Polymerase helps build DNA polymersDNA Polymerase helps build DNA polymers

Did you notice that enzyme all Did you notice that enzyme all sound the same?sound the same?

All enzymes end in “-ase” All enzymes end in “-ase” DNA PolymerDNA PolymeraseaseSucrSucrasease

Factors affecting enzyme activityFactors affecting enzyme activity

1. TEMPERATURE1. TEMPERATURE

2. Concentration of Enzyme2. Concentration of Enzyme

3. Concentration of Substrate3. Concentration of Substrate

4. pH4. pH

5. Inhibitors5. Inhibitors

Competitive inhibitionCompetitive inhibition - molecules bind - molecules bind to the active site and prevent the to the active site and prevent the substrate from bindingsubstrate from binding

Non-competitive inhibitionNon-competitive inhibition - molecules - molecules that bind to a site other than the active site that bind to a site other than the active site but change the shape of the active site so but change the shape of the active site so that it cannot bind the substrate that it cannot bind the substrate

Types of InhibitionTypes of Inhibition

Enzymes in Enzymes in BiotechnologyBiotechnology

How does pectinase How does pectinase work?work?

Pectin is the cement Pectin is the cement that holds plant cells that holds plant cells together. together. PectinasePectinase helps farmers break helps farmers break down the plant cells down the plant cells faster. For example it faster. For example it might help a farmer might help a farmer release the juice from release the juice from apples faster to make apples faster to make lots of Apple Juice.lots of Apple Juice.

Other enzymes in Other enzymes in biotechnology…biotechnology…

Biological washing powderBiological washing powderMeat tenderizerMeat tenderizerProduction of glucose syrupProduction of glucose syrup

Chemistry of Living Systems

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