Site of most chemical reactions in the cell

The Levels of organization

Anything that has Anything that has massmass and and takes up takes up spacespace (volume). (volume).

All matter is made up of All matter is made up of atoms.atoms.

ATOMSATOMS

The small units of matter The small units of matter

Made up of Protons, Neutrons, Made up of Protons, Neutrons, and Electrons and Electrons

Atoms are smaller than cells Atoms are smaller than cells

Pure substances made up of only one type of atom

-Major 4 elements:CarbonHydrogenOxygenNitrogen

(C)(H)(O)(N)

COMPOUNDSCOMPOUNDS

• combination of combination of 2 or more elements2 or more elements in in definite proportionsdefinite proportions– Ex: water, salt, glucose, carbon dioxide Ex: water, salt, glucose, carbon dioxide

Inorganic Compounds

Do not contain carbon(exceptions: CO and CO2)

Types:

WaterSaltsAcidsBases

usually

Organic Compounds

Always contain C and HUsually have O and NMay contain P and SAssociated with life:

bodies of organisms, remains, waste

Four Types of Organic CompoundsCarbohydratesLipidsProteinsNucleic Acids

The smallest part of a The smallest part of a compound that has the compound that has the properties of that compound. properties of that compound.

Example: HExample: H22OO

Atoms of the same element that bond inpairs to become stable.

H2

O2

N2

Never found innature as singleatoms.

FORMULAS FORMULAS • Chemical symbols and numbers that Chemical symbols and numbers that

make up a compound ("make up a compound ("reciperecipe")")

• Structural FormulaStructural Formula – Line drawings of the – Line drawings of the compound that shows the elements in compound that shows the elements in proportion and how they are bondedproportion and how they are bonded

• Molecular FormulaMolecular Formula – the ACTUAL – the ACTUAL formula for a compoundformula for a compound

CC66HH1212OO66

THE PROTON

p+

• Fat (heavy)

• Positive (charge)

• Doesn’t move (lazy)

THE NEUTRON

N°

• Fat (heavy)

• Neutral (charge)

• Doesn’t move (lazy)

THE ELECTRON• Skinny (very light)

• Negative (charge)

• Moves a lot (runs around)

e-

Review: Subatomic Particles

e-

N°

p+

The outermost electrons of an element.

Valence electrons are the most reactive and are involved in chemical bonding.

http://www.Chemicool Periodic Tablechemicool.com/

• Hold atoms in molecule togetherHold atoms in molecule together

• 3 types of chemical bonds:3 types of chemical bonds:– IONICIONIC

– COVALENTCOVALENT

– HYDROGENHYDROGEN

• 1 or more electrons are 1 or more electrons are TRANSFERREDTRANSFERRED from one atom to anotherfrom one atom to another

• If atom loses an electron: If atom loses an electron: POSITIVEPOSITIVE chargecharge

• If atom gains an electron: If atom gains an electron: NEGATIVENEGATIVE charge charge

• These newly charged atoms are now These newly charged atoms are now called called IONSIONS– Example: NaCl (SALT)Example: NaCl (SALT)

• Electrons are Electrons are SHAREDSHARED by atoms by atoms

• New structures that result are called New structures that result are called MOLECULESMOLECULES

SHARING IS CARING!SHARING IS CARING!

Which type of bond? Covalent or ionic?

Which type of bond? Covalent or Ionic?

Valence Electrons

bonding that involves electronegative attraction between H atoms

1) Universal solvent

2) Medium for chemical reactions

3) Raw material for chemical reactions

4) Transport medium

Penny ActivityPenny Activity• Obtain a penny and a pipette with HObtain a penny and a pipette with H22OO

• Your goal is to place as many drops of water on Your goal is to place as many drops of water on the surface of the penny without spilling the Hthe surface of the penny without spilling the H22O.O.

• Place drops on the penny one at a time and keep Place drops on the penny one at a time and keep track (be honest) of how many you place on the track (be honest) of how many you place on the penny.penny.

• Record your results in your notes.Record your results in your notes.

Penny ActivityPenny Activity• Why were you able to place so many drops Why were you able to place so many drops

of water on the penny?of water on the penny?

• What type of bond might be involved?What type of bond might be involved?

• What are adhesion and cohesion?What are adhesion and cohesion?

• Did the side of the penny affect your Did the side of the penny affect your results?results?

Contain C, H, O

Ratio of H and O is 2:1

Most end in “ose”

Building Block = MonosaccharideGlucoseFructoseGalactose

C6H12O6

C6H12O6

Same MolecularFormula

DifferentStructuralFormulas

Mono=one

Molecules formed by joining two monosaccharides

Glucose + Glucose Maltose

Glucose + Fructose Sucrose

Glucose + Galactose Lactose

C12H22O11

Di=two

Long chain of joined monosaccharides

(Sugar Polymer)

Organisms store excess glucose aspolysaccharides

Plants store as STARCH

Animals store as GLYCOGENExamples: cellulose, chitin

Poly=many

1) Quick energy source

2) Make cell structures (cell walls)

How are complex carbohydrates How are complex carbohydrates formed and broken down? formed and broken down?

H2OMaltose

(Disaccharide)Process that joins molecules by

removing water

H2O

Maltose

H HO

Glucose Glucose

Process that breaks down molecules byadding water.

Fats Oils Waxes

Contain C, H, O

Less O then found in Carbohydrate

Building Blocks =1 Glycerol

&3 Fatty Acids

1) Reserve energy source (9 calories/gram)

2) Component of cell structures(example: Cell Membrane)

3) Insulation and Cushioning

Lipids are found in the cell membrane of cells.

Contains C, H, O, N

Building Block = Amino Acids

Amino Acid consists of:1) Central C atom2) Carboxyl group3) Amino group4) H atom5) Representative group ®

Sometimes contains S and P

Amino Acid

R = H (Glycine)

R = CH3 (Alanine)

AN R GROUP IS ANY AN R GROUP IS ANY GROUP OF ATOMS – GROUP OF ATOMS – THIS CHANGES THE THIS CHANGES THE PROPERTIES OF THE PROPERTIES OF THE PROTEIN!PROTEIN!

What is the R group in this compound?

H2O

Peptide Bond

________

What is the name of this process?

Protein consisting of three or moreamino acids joined together

Polypeptide

1) Structural Parts (hair, nails, cartilage)

2) Pigments (blood, skin, eyes)

3) Contractile Material (muscle tissue)

4) Antibodies (protect against infection)

5) Hormones (Chemical messengers)

6) Enzymes (control chemical reactions)

7) Energy Source (4 calories/gram)

Contains C, H, O, N, P

Two Types:Deoxyribonucleic Acid (DNA)Ribonucleic Acid (RNA)

DNA – Hereditary Material RNA – Controls activities and development

of cells

Building Block = Nucleotide

Nucleotide consists of:

1) Five carbon sugar

2) Phosphate group

3) Nitrogen base

P

adeninethymineguaninecytosine

(DNA only)

uracil (RNA only)

AT

GC

U

AGGTCAATGCCG

TCCAGTTACGGC

DNA

GAUCCUACGUAC

CUAGGAUGCAUG

RNA

DNA RNA

Double Stranded Single Stranded

Deoxyribose Ribose

Thymine Uracil

P

P

P

P

P

PG C

A

T

C G

A

T

P

P

Base Pair RuleA TG C

ACIDS & BASESACIDS & BASES• Acids: Begin with "H-" (excess of H+ Acids: Begin with "H-" (excess of H+

ions: hydrogen)ions: hydrogen)– Ex: lemon juice (6), stomach acid (1.5), acid Ex: lemon juice (6), stomach acid (1.5), acid

rain (4.5), normal rain (6)rain (4.5), normal rain (6)

Facts about AcidsFacts about Acids

• Acids turn litmus paper Acids turn litmus paper REDRED and usually and usually taste taste SOURSOUR. .

• You eat acids daily (coffee, vinegar, You eat acids daily (coffee, vinegar, soda, spicy foods, etc…)soda, spicy foods, etc…)

ACIDS & BASESACIDS & BASES• Bases: end with -OH (excess of hydroxide Bases: end with -OH (excess of hydroxide

ions: Oxygen & Hydrogen)ions: Oxygen & Hydrogen)– EX: oven cleaner, bleach, ammonia, sea water, EX: oven cleaner, bleach, ammonia, sea water,

blood, pure waterblood, pure water

Facts about BasesFacts about Bases

• Bases turn litmus Bases turn litmus BLUEBLUE. .

• Bases usually feel Bases usually feel SLIPPERYSLIPPERY to touch and to touch and taste taste BITTERBITTER. .

Neutralization Reactions Neutralization Reactions

• When an acid reacts with a base to produce When an acid reacts with a base to produce a salt and water.a salt and water.

pH SCALEpH SCALE• measures degree of measures degree of

substance alkalinity or substance alkalinity or acidityacidity

• Ranges from Ranges from 0 to 140 to 14

• 0 – 5 strong acid0 – 5 strong acid

• 6-7 neutral6-7 neutral

• 8-14 strong base8-14 strong base

Effects of Acid Rain

• The goal of the body is to maintain The goal of the body is to maintain HOMEOSTASISHOMEOSTASIS – to do this when pH is – to do this when pH is concerned, we add weak acids & bases to concerned, we add weak acids & bases to prevent sharp changes in pH. prevent sharp changes in pH.

• These are called These are called BUFFERSBUFFERS

Homeostasis: relatively stable internal environment a.k.a: dynamic equilibrium

Protein substance …made on ribosomesControl all chemical reactions in organisms

Not changed by the reactionCan be used again

Referred to as an “organic catalyst”

Substrate: Substance enzymes works on

Lower activation energy (NRG needed to start Rx)

Dr. David R. Howard, Asst. Prof. Univ. of Wisconsin La Crosse

Usually ends in “ase”

Name often comes from substrate

Examples:

Maltase (Maltose Glucose)

Protease (Breaks down proteins)

Lipase (Breaks down lipids)

Temporary union of the enzyme andsubstrate at the “active site”

Active Site:

- Area of an enzyme - Substrate molecule fits in shape of active site- Active sites are specific for substrates

Figure 8.16

Substate

Active site

Enzyme

(a)

Figure 8.16 (b)

Enzyme- substratecomplex

Enzymes work on specific substratesReason: specific active site on enzyme

Example: Lactase only breaks down LactoseMaltase only breaks down MaltoseCellulase only breaks down cellulose

1) Small amounts of enzymes can cause the reaction of large amounts of substrates

2) Enzymes allow cell reactions to occur at “normal” temperatures

3) Enzymes work best at specific temperaturesOptimal Temperature is when enzymeis most effective

Denaturation: Deformation of active sitedue to high temperature

4) Enzymes work best at certain pH

Human Examples:Amylase pH 8Pepsin pH 2Trypsin pH 8

5) Rate of an enzyme controlled reaction depends on the concentration of enzymes and substrates.

- more enzymes faster the rate of reaction- maximum rate (enzymes = substrates)

** When there is a fixed amount of enzyme ** When there is a fixed amount of enzyme and an excess of substrate molecules -- the and an excess of substrate molecules -- the rate of reaction will increase to a point and rate of reaction will increase to a point and then level off**then level off**

6) Some enzymes need coenzymes to function

Coenzymes:- are not proteins

- may be part of enzyme molecule or a separate molecule

- may be altered during E-S Complex, but return to original form after reaction

- may be vitamin or made from vitamin

7) Most enzymes functions inside cells, some functions outside

- all enzymes are made by cells

- digestive enzymes function outside cells

Enzymes(and beyond …)

• Inhibitors—reduce the productivity of enzymes as seen to the right with herbicides.

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