Chapter 2: The Chemistry of Life2.1 Nature of Matter:____: smallest part/basic unit of matter

3 sub-atomic particles: ____________________________

_________: pure substance …all the same type of atoms(about 26 elements compose all living things..most abundant are: _________ )

_____________ : # of __________

_______________________ _______________ (ie..mass of nucleus)

What are the element symbols for…

• Carbon

• Hydrogen

• Oxygen

• Nitrogen

• Sulfur

• Phosphorus

• Sodium

• Chlorine

• Potassium

• Calcium

• Manganese

• Flourine

• Helium

• Magnesium

• Aluminum

• Iodine

• Lead

• Silver

• Lithium

• Mercury

____________: elements with different neutron # than a stable atom

ex: 14C, 3H, 32P, 34S

_______________: have unstable nuclei – break down at a known rate, give off radioactive particles (gamma rays, etc)

* Dangerous AND useful, too

* ex: fossil dating, bone scans, GI series, chemotherapy

__________: substance formed by 2 or more elements in a fixed ratio

• Physical and chemical properties of compound are different than atoms composing the compound

• _________: smallest unit of most compounds

Sodium Chlorine Sodium

Chloride

2.1 Nature of Matter continued

1. ______________: attractions between ions of opposite charge

– when atoms gain or lose electrons, ions are created

BONDING PATTERNS:

Na+

Cl–

2. _____________: join atoms into molecules through electron sharing• when two atoms share one or more pairs of outer shell electrons

CH4 = ?

_______________: When covalently bonded atoms share electrons ________

Ex: CO2

___________: Electrons are shared __________ between atoms, creating a _______ molecule

Ex: H20

___________: weak bonds important in the chemistry of life

– charged regions on water molecules are attracted to the oppositely charged regions on nearby molecules

– Ex: water to water (cohesion)

Polar Covalent/Non-polar Covalent/ H Bonds

Why Water Supports All Life:

1. ________ (w+w) and _________ (w+other)– allows water to move from roots�leaves– some insects can walk on water due to

cohesive surface tension– universal solvent – can dissolve more

solutes than any other solvent

2. Moderates temperature (___________):– takes a lot of energy to disrupt hydrogen

bonds � water can absorb lots of heat without a large rise in temp

– As water cools� a slight drop in temp releases a large amount of heat

– water molecules take energy with it when it evaporates � evaporative cooling

Mixtures: Solutions and Suspensions:__________: composed of 2 or more elements or compounds physically mixed, not chemically combined(ex: salt and sugar together)

2 types of Mixtures:

a) __________: where components are evenly distributed (ex: salt water)* water = solvent NaCl = solute* polarity of water allows it to dissolve ionic compounds and polar molecules (ex: salts, sugars, minerals, gases, other solvents like alcohol)

b) __________: when materials don’t dissolve in water, but break up into tiny pieces which do not settle out (they are suspended by the moving water)* ex: blood (water has dissolved compounds, blood cells and other components (lipids) which remain suspended in mixture)

________: a compound that forms ___ ions in solution

________: a compound that produces ___ (hydroxide) ions in solution

______ or ______ (____) is measured onthe pH scale:

• From 0 (most acidic) to 14 (most basic)

• The pH of most cells is kept close to 7 (neutral) by buffers (substances that resist pH change)

• Each step on pH scale is a factor of __.(ex: pH 5 is 10x more acidic than?)

The chemistry of life is sensitive to acidic and basic conditions

When the number of H+ is equal to the number of OH- � water

H+ + OH- � H20

_______: weak acid or weak base which can keep a pH stable

ex: _______: most important buffer in body- maintains homeostasis in blood

2.3 Organic Chemistry: The Chemistry of Carbon

• “_______”: must contain at least one carbon. CH4 = simplest organic molecule

• Carbon has _ valence electrons

• Therefore, carbon will ______ make 4 bonds with other atoms

• Carbon can bond with other carbons, form chains, rings

• Ability to form millions of different compounds with other elements

The Four Macromolecules of Life__________ (polymer) made by joining many monomers (single unit)

__________: chemical rxn which joins monomers to make polymers

The four main classes of biological molecules:

1. ___________ (sugar, starches, cellulose)

2. ___________ (wax, fats, oils, steroids)

3. _______ (muscle, hair, hormones, enzymes)

4. ___________ (DNA and RNA)

1. CARBOHYDRATES: Monomer = Monosaccharide

•Contain C, H, and O in a 1:2:1 ratio•Most end with “ose”•An animal’s main energy source•______ are burned first in the body•________________: (C6H12O6): glucose, fructose, galactose

•________________: sucrose, lactose, maltose•_______________: (complex carbohydrates)

– A) glycogen (carb storage animal liver)– B) starch (carb storage in plants)– C) cellulose (cell walls, cotton) “roughage”– D) chitin (exoskeletons of arthropods)

2. LIPIDS: Monomer = Fatty Acids

* Mostly _______ atoms linked by

nonpolar covalent bonds

* _________ - storage molecules

(burned after carbs are gone)

* ________in water (polar)

* Soluble in nonpolar solvents (ether)

* More energy in lipids than in carbs

- 9 cal/g Lipid vs. 4 cal/g Carb

* Examples: triglycerides, phospholipids,

steroids (cholesterol), waxes, oils, fats

* ____________= 3 fatty acids + 1 glycerol

* ____________: all single bonds in chain

- solid at room temp (ex: butter, lard)

* ____________: one or more C=C bond in chain

- liquid at room temp (ex: all oils)

3. NUCLEIC ACIDS: Monomer = Nucleotide• Nucleic acids (___________) store and transmit genetic information

• DNA = ______________

• RNA = ______________

• Large macromolecules containing _____________

• One nucleotide = 5-carbon sugar, phosphate (PO4-), nitrogenous base

The sugars and phosphates are the backbone for the nucleic acid

DNA’s sugar = deoxyriboseRNA’s sugar = ribose

4. PROTEINS: Monomer = Amino Acid

• Essential to the structures and activities of life

• Contain ________________

• 50% of your dry weight

• examples of groups of proteins:

1. enzymes (amylase, sucrase, maltase, lactase) –______________

2. structural (collagen, elastin)

3. contractile (actin, myosin)

4. transport (hemoglobin, protein channels)

5. hormones (insulin)

Each amino acid has:•An ________________

•A _________________

•An __ group, which distinguishes each of the __ different amino acids

AMINO ACID: Structure

* Each amino acid has specific properties based on the R-group

* ________ link amino acids together � polypeptide (protein)

Amino acids are assembled into polypeptide chains according to

instructions coded in the DNA.

PROTEINS: 4 Levels of Organization

_____________: the sequence of amino acids in its polypeptide chain

___________________: the coiling or folding of the chain

_____________: the overall three-dimensional shape of a polypeptide – created when R-groups bond

_____________: the association of two or more polypeptide chains

2.4 Chemical Reactions and Enzymes•__________: process that changes or transforms one set of chemicals into another•Those chemicals that enter into a reaction are the “________”, those that are made are the “_________”•Chemical reactions change the bonding patterns in the reactants•Energy is released or absorbed when chemical bonds are formed or broken during a reaction

•Rxns releasing energy generally happen spontaneously•Rxns which absorb energy need energy to start them•Some energy releasing rxns need activation (input of )energy to get started

• Lower the ________________ of chemical reactions (they are ______)

• The reactants they “work” on are called “______________”

• Most enzymes are named for their substrates with an “-ase” ending

Ex: sucrase digests sucrose lactase digests lactose

• VERY shape specific (“lock and key”) reaction with active site on enzyme (where substrate and enzyme join)

Enzymes are vital proteins that run biochemical rxns

One Enzyme : One Substrate

•Enzymes have unique three-dimensional shapes so they can fit onto their specific substrate

•Shapes determine function and which chemical reactions they can perform

•All related to their 3-D folding pattern born from?

• ___________________________________

• Enzyme inhibitors can alter enzyme function:

– _____________ inhibitor: blocks active site, substrate can’t attach and remains unchanged

– _____________ inhibitor: alters enzyme’s function by changing its shape

– Many poisons, pesticides, and drugs are enzyme inhibitors

Factors Which Affect Enzyme Activity:

Some food for thought:1.Why do we put lemon juice on apples?2.What is the purpose of a fever?3.What happens when a raw egg hits a hot fry pan?4.Why do we put produce/perishables in the fridge?5.How does a Siamese cat get it’s color pattern?

– DNA sequences spell out the amino acid sequences of proteins

– _______ in the ___sequence � wrong ________ sequence � wrong ________ shape � no function

– Ex: Lactose Intolerance :

Mutations in lactase gene�mutations in lactase amino acid chain sequence �defective lactase shape�enzyme can’t fit onto lactose substrate �lactose does not get digested.

Q: Why is it a big deal?

A: If YOU don’t digest the lactose in your digestive tract, all the E.coli will…all of their waste made from eating all this food will leave you with cramps, bloating, and diarrhea…not fun!

GENES = Sequences of DNA

Lactase enzyme