CHAPTER 2Chemistry of Life

2.1 THE NATURE OF MATTER Key questions

What are the three atomic particles that make up an atom? How are all of the isotopes of an element similar? In what ways do compound differ from their compound elements? What are the main types of chemical bonds

VOCAB: atom Nuclues Electron Element Isotope compound Ionic bond Ion Covalent bond Molecule Vand der waals Forces

ATOMS Democritus: 2500 years ago

What happens when you break a piece of chalk? Atom: Atomos “unable to cut”

Parts of an atom: Protons:

positive charge Clumped in nucleus

Neutrons: No charge Clumped in nucleus Same mass as protons

Electrons: Negative charge Much smaller then proton/neutron 1/1840 the mass Constantly moving around positive core

**Same amount of protons and electrons = a Neutral charged atom!

CARBON ATOM

NATURE OF MATTER CONTINUED… Elements vs isotopes:

Element: Pure substance that consists of entirely one atom Over 100 elements are known 2 dozen are commonly found in living organisms Represented on the periodic table

www.ptable.com/ Isotopes:

Atoms of the same element that differ in the number of neutrons

Protons + neutrons = MASS NUMBER Example: carbon 12, 13, 14 Because they have the same number of electrons, all

isotopes of an element have the same chemical property

Radioactive: their nuclei are unstable and breakdown at a constant rate over time

2.1 CONTINUED… Chemical compound:

Substance formed by the chemical combination of two or more elements in definite proportions

Examples: h20, NaCl Chemical bonds

Ionic: One or more electrons are transferred from one atom to

another This creates a positive and negative atom therefore an

attraction Covalent

Electons travel between each atoms nucleus http://www.youtube.com/watch?v=xTx_DWboEVs

Van der waal forces Attractions bewteen covalent bonding www.visionlearning.com/library/...1/CHE1.7-bonding

.htm

2.2 PROPERTIES OF WATER Key questions

How does the structure of water contribute to its unique properties How does water’s polarity influence its properties as a solvent Why is it important for cells to buffer solutions against rapid

changes in PH Vocab:

Hydrogen bond Cohesion Adhesion Mixture solution solute Solvent Suspension PH scale Acid Base buffer

2.2 WATER Covalent bond/ neutral charge: 10+ 10-

Polarity: because of the covalent bond….h2o has a unique

shape There is a + and – pole within the molecule. This polarity encourages Hydrogen bonding

Hydrogen bond: The polarity of the hydrogen and oxygen attract

each other similar to a covalent bond

HYDROGEN BONDING

WATER CONINTUED… Cohesion

Attraction between molecules of the same substance

To be drawn together Examples: beading and surface tension

Adhesion Attraction of molecules of different substance Examples: water in a cylinder

Heat capacity Tolerant of heat High heat capacity Protects the organisms within. Why?

Mixture A material composed of two or more elements or

compounds that are physically together no chemically combined. EX: salt and pepper

Solutions: all components of a solution are evenly distribute by

a polar bond Solute: substance that is being disolved Solvent: doing the dissolving

Suspensions: No dissolving Separate into pieces so small that they do not settle

out. Example: blood, dressing

ACIDS, BASES, AND PHWater molecules often split to form ions.

(hydrogen and hydroxide ions)

pH scale scale made to indicate the level of these H+ ions

in the solution. Ranges from 0-14 0 = acid, 7 = pure Each step on the ladder is a matter of “10”

PH SCALE AND ENVIRONMENTAL EFFECTS

ACIDS, BASES, AND BUFFERS CONTINUED…

Acids pH below 7 Higher concentration of H+ Strong acids at 1-3

Bases pH above 7 Lower concentrations of H+ Strong bases 11-14 (lye=soap)

Buffers Ph levels in body must be kept within 6.5-7.5

buffers are weak acids /bases that help control the drastic change.

REVIEW 2.2 Key questions

How does the structure of water contribute to its unique properties How does water’s polarity influence its properties as a solvent Why is it important for cells to buffer solutions against rapid

changes in PH Vocab:

Hydrogen bond Cohesion Adhesion Mixture solution solute Solvent Suspension PH scale Acid Base buffer

2.3 CARBON COMPOUND Key questions

What elements does carbon bond with to make up life’s molecule?

What are the functions of each of the four groups of macromolecules

Vocab Monomer Polymer Carbohydrate Monosaccharide Lipid Nucleic acid Nucleotide Protein Amino acid

WHY IS CARBON SO COOL?

4 valence electrons to form strong covalent bonds

Carbon can bond with many elements for ‘life” Hydrogen Oxygen Phosphorus Sulfur nitrogen

Bond to itself Can from single, double, or triple covalent bonds Can be unlimited in length Can even circle onto itself Most versatile of elements

MACROMOLECULES Macromolecules: made up

thousands/hundreds of thousands of smaller molecules

Formed by Polymerization: when large compounds are built by joining smaller ones: monomers and polymers

monomers: single

Polymers: many parts

FOUR TYPES OF MACROMOLECULES FOR LIFE Carbohydrates

Carbon/ hydrogen / oxygen (1:2:1 ratio) Breaking of these bonds are the primary source

of energy Sugars

Simple sugars (monosaccharides) Single sugar molecules Ex: glucose, galactose and fructose

Complex carbohydrates polysaccharides

Lipids Mainly carbon and hydrogen Not water soluble Common categories

Fats Oils waxes

Can be energy but commonly as membrane coverings

when a glycerol is combined with fatty acid Saturated: if each carbon is connect by single bond to

another carbon Unsaturated: at least one double carbon-carbon bond Poly-unsaturated: more than one double carbon bond

Nucleic acids Macromolecules formed from H,O, N, C and

phosphorous Assembled from polymers known as

nucleotides Nucleotides: 3 parts example (ATP)

5 carbon sugar Phosphate group Nitrogen base

Nucleic acids store and transmit heredity and genetic information Examples: DNA RNA

Proteins Made from polymers AMINO ACIDS

Covalent bonds called peptide bonds Some control rate of cell reaction Some form cell structures Aid in transport Many of chains of peptides

Structure 20 different types Bonding sites are the same

Organizations Peptide chains

2.3 REVIEW Key questions

How does the structure of water contribute to its unique properties How does water’s polarity influence its properties as a solvent Why is it important for cells to buffer solutions against rapid

changes in PH Vocab:

Hydrogen bond Cohesion Adhesion Mixture solution solute Solvent Suspension PH scale Acid Base buffer

2.4 CHEMICAL REACTIONS AND ENZYMES Key questions

What happens to chemical bonds during chemical reactions

How do energy chances affect whether a chemical reaction will occur

What role do enzymes play in living things and what affects their function

Vocab Chemical reaction Reactant Product activation energy Catalyst Enzyme substrate

CHEMICAL REACTIONSWhat is a chemical reaction? Process of changing or transforming one set of

chemicals into another. Involve changes in the chemical bonds that join

atoms in compounds SO……that means?

**MASS AND ENERGY ARE CONSERVED DURING CHEMICAL REACTION**

Reactants: chemicals that go into the reaction Products: chemical/compound resulting from the

reaction Example : pg. 50 blood stream/co2

ENERGY IN REACTIONSEnergy is released or absorbed chemical bonds

are broken or broken Releasing energy can happen on their

own/spontaneously Example: burning hydrogen gas

2h2 + O22H2O Energy is released in the form of heat!

Absorbing energy needs an energy source Example: returning h2o to hydrogen and O2 gases

So much energy needed that it can’t happen on its own Energy sources: Activiation energy: Energy needed to start a

chemical reaction

ENZYMES Proteins that act as a biological catalyst Catalyst: substance that speeds up chemical

reaction Example blood stream and carbonic anhydrase and its

effect on co2 and h20 Lock and key (substrates)

regulation