Biology notes-Chapter 2-The Chemistry of Life….Name___________________________________

I. The nature of matter-A. Atoms-________________________________________

Derived from Greek word Atomos,which means “unable to be cut”As described by _____________________,2300 years ago 100 million atoms would make a room about 1 cm long DOES contain__________________particles that are smaller than an atom

Particle Size Location Charge electron 1/1840th of mass of a

proton(amu)Energy levels in an electron cloud

proton 1 amu +neutron 1 amu nucleus

Calculating subatomic particles:PROTONS=Atomic Number=electrons(in a neutral atom)MASS NUMBER=p + nN=Mass-pElectrons=p=atomic number

Since atoms tend to have p=electrons ,the + and – charge balance ,making them neutral

_________________center of atom bound by STRONG FORCES. Electrons are attracted to + nucleus ,but are held in levels by the energy of their

motionB. Elements and Isotopes

____________________=PURE SUBSTANCE CONSISTING OF ONE KIND OF ATOM

More than 100 in existence but ~24 compose living things Represented by 1 or 2 letter symbol Common symbols:

Name symbol Name symbolHydrogen Chlorine Helium PotassiumLithium Calcium Boron Arsenic

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Carbon Bromine Nitrogen Radon Oxygen Silver Fluorine Gold Neon Mercury sodium Tin Magnesium

Iodine

Aluminum Barium

Silicon Radium Phosphorus

Uranium

Isotopes-atoms of the same element with a different number of neutrons----example:C-12,C-13,C-14----all averaged together for the atomic mass

Isotopes are identified by ____________________. Radioactive Isotopes have unstable nuclei and break down at a constant rate

over time… Radioactive Isotopes

uses:_______________________________________________________________________________________-

All isotopes of an element have the same chemical properties because they have the same # of ______________-.

‘WEIGHTED MASS”-ie .Atomic weight=average mass of all isotopes for an element

C. Chemical Compounds=______________________________________________________________________

Shown by a chemical formula Physical and chemical properties for an element differ a lot when they are

bound in a compound What is the ratio of H:O on H2O?____________________________ Physical

properties:__________________________________________________________________________________

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Chemical properties:_________________________________________________________________________________

D. Chemical Bonds hold together atoms in a compound1. Ionic Bonds-electrons are transferred from one to another creating an

electrical ,ionic charge that binds the atoms

Tends to happen between metals and nonmetals Looking @ p.37 ,draw what happens in a NaCl bond

2. Covalent Bonds-_____________________ The moving electrons of both atoms travel in the orbits of both atoms Double or triple bonds occur when 4 or 6 electrons are shared ____________________-smallest unit of a compound See drawing 2-4 on p.37 and draw the bond of H2O

E. Van der Waals Forces_intermolecular forces that result from unequal sharing that results in tiny + or – charges in covalent bonds

Help hold a molecule together a little more….see example of gecko on p.38 Rapid movement of electrons can create regions of tiny (+) and (-) charges/As

some molecules are close together,slight attraction between oppositely charged regions of nearby molecule-esp. when molecule is large

II. Properties of water Single most abundant compound in most living thingsA. The Water Molecule

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_____________-because of an uneven distribution of electrons between O and H atoms

O side is more – pole because it has more electrons It is ,essentially ,neutral ,but has a more – and more + end Because of this polarity water molecules can attract one another Polar charges are written in ( ) to show they are weaker than ionic charges H bonds not strong ,but water can form___________ H bonds…..causing

many of its properties/bonding with itself O,N, and F A single water molecule can be involved in as many as 4 H-bonds __________________-attraction between molecules of the same

substance…water is cohesive-example-surface tension allows spiders to walk on water

___________________-attraction between molecules of different substances-example-water creating meniscus as attaches to sides of graduated cylinder

H20 bonding in H2O is Unique orientation that enables expanding as freezes

HEAT CAPACITY---because of H-bonds ,takes a lot of heat to get water molecules moving faster, creating high heat capacity….helping organisms maintain body temp’s

Look @ ppt and describe the effect of capillary action and how it is used in nature:_____________________________________________________________________________________________________________________________________________________________________________________________________________________

B.Solutions and Suspensions Water is often in a ________________________,where 2 or more

elements or compounds are PHYSICALLY combined 2 types;

1) __________________mixture where components evenly distributed

Ions are surrounded by water molecules and evenly distributed

_____________-substance dissolved ______________-substance that does dissolving

2) ____________________-mixtures of water and non dissolved materials—blood cells in a suspension of water in vessels

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B. Acids,Bases and pH- Water molecule can react to form ions.Draw reaction as

shown @ bottom of p.42:

_________________indicates concentration of H ions in solution

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BASEAcid

Each step represents a power of 10-example-pH of 5 has 10 x as many H+ ions as same qty of ph 6

______________-higher concentrations of H+ ions and pH <7

_______________-alkaline-lower H+ concentration and pH>7

________________weak acids or bases that react w/ strong ones to prevent sharp pH changes

Buffers are dissolved in life’s fluids ,playing an important role in maintaining homeostasis in organisms

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III. Carbon Compounds In the 1800’s,chemists thought

compounds created by living things –organic compounds-were much different than others

In 1838 a German chemist made the organic compound,urea ,from nonorganic ammonium cyanate…Thus principles of chemistry governing nonliving could be applied to living things

_________________________is actually the study of almost all C-compounds-many not having anything to do w/ living things.

A.The Chemistry of Carbon Why is carbon special?---1) It has 4

valence electrons and can make 4 bonds 2)It can bond w/ many other elements. Includes H,O,P,S,N to make molecules of life

3)C can bond to other C’s in single,double or triple bonds 4)C can form chains and rings

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methane acetylene

butadiene

benzene

isooctane Forms millions of different complex structures.

B.Macromolecules

“Giant molecules found in organisms “ Formed by _________________________________,in which

large compounds are built by joining smaller ones. ______________________-small units –join to form

__________________________-large molecules

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The 4 groups of macromolecules are________________________________________________________

C.Carbohydrates

Made up of C,H and O in ,uaually, a ratio 1:2:1. Used by organisms for energy-main source. Used for structure-by plants and some animals. Break down of sugars,like

glucose(C6H12O6)provides immediate energy for cell activities

sucrose Starches are complex carbohydrates-stores extra

energy

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Single sugars are called ______________________,like glucose,galactose and fructose.

Sucrose=disaccharide-made of 2 sugars(notice structure in picture)

______________________________are large molecules formed from monosaccharides

-such as glycogen or animal starch—glycogen from the liver helps out when glucose levels run low.This is also stored in muscles for energy.

Plants have plant starch and cellulose ,which gives plants their structure----major component of wood and paper.

D.Lipids

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CARB MONOMER

Large ,varied group of macromolecules that are

generally are ________ in water Includes fats ,oils,waxes Made mostly of C,H and O Groups are ____________________. Can be used to store energy Some are parts of biological membranes or

waterproof coverings Many are formed when glycerol is combined w/ fatty

acids1) If each C atom is joined to another

C atom by a single bond it is called ________________________.This is because it has the max # of H-atoms.These are________________.

2) If there is at least 1 C-C double bond ,it is called ___________________________.These are ______________________@ room temp.example-olive oil

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If there is more than 1 C-C double bond,it is__________________________________examples:oils such as corn,sesame,canola and peanut

Monomer basically glycerol and fatty acids….see analyzing data,p.48

E. ____________________=macromolecules

containing C,H,O,N and P

Polymers assembled from monomers called_________________________________, which contain 3 parts:

1. 5-C sugar2. phosphate group3. nitrogenous base

Nucleic Acids store and transmit ______________or genetic info…2 types of nucleic acids

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1. __________________________________-,involved in protein synthesis and has the sugar_________________.

2. Single strand

RNA3. _____________________________

______-contains genetic code and has the sugar ____________________________.

DNA Double helix Contains deoxyribose For heredity

F. _________=macromolecules containing C,H,O and N and composed of amino acids (monomer)

_______________________ are compounds w/ an amino group(-NH2) on one end and a carboxyl group(-COOH) on the other end.

Look @ Fig 2-17 on p. 48

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basic amino acid formula More than 20 amino acids in nature All amino acids alike in region where they

may be joined by covalent bond.Thus any amino acid can be joined to any amino acid-by bonding an amino group to a carboxyl group

The portion of each amino acid that is different is the side chain called a ____group.Some of these R groups are acidic and some are basic…some polar and some nonploar.Some have C rings .

The instructions for assembling amino acids into different proteins is stored in____.

Each protein has a specific role….various functions include:

1. control _____________rates(enzymes).

2. regulate cell processes .3. forming bones and muscles4. transporting substances into and

out of cells5. fighting diseases

up to 4 levels of organization

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1st –sequence of amino acids in a protein chain2nd –amino acids within a chain can be twisted or folded3rd –chain itself is folded—If there is more than one chain,each chain has a specific arrangement in space.4th –Van der Waals forces and H-bonds help maintain a protein’s shape.

IV. Chemical Reactions and EnzymesA. Chemical

reactions=_______________________________________________________________________________________________

Some are fast and some are slowThe elements entering into the reaction are ________________and that which is produced are the ________________________.

Co2 + H2OH2CO3 reaction that allows release of CO2 from the bloodstream

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The above reaction is

reversed in the lungs.

Chemical reactions always involve the breaking of bonds in ____________ and the formation of new bonds in _____________.

B. Energy in ReactionsEnergy is released or absorbed in chemical reactions.

1. Energy Changes-Chemical Reactions that release energy are called ______________________ and often occur spontaneously.

Example: 2 H2 + O2 2 H2O….energy released as heat/sometimes as light and sound

Chemical reactions that require energy are called_________________ and usually doesn’t occur by itself

Example: 2 H2O 2H2 + O2 requires an electrical current---NEEDS AN ENERGY SOURCE

Organisms must have a source of energy to carry out necessary reactions.Plants get this from products of _____________________and animals get it

reactants products

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from consuming plants or other animals….thus from metabolizing food

2. Activation energy-____________________________________________________

B. Enzymes-________________________________________________________

A ______________ is a substance that speeds up the rate of a chemical reaction by lowering activation energy.Enzymes speed up reactions that take place in a cell________________________speeds up the release of CO2 from the bloodstream.Enzymes are specific to the reaction they speed up and usually named on the basis of the reaction.

C. Enzyme Action-

Reactants must collide w/ sufficient energy to make _____________.

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1. ENZYME-SUBSTRATE COMPLEX-enzymes provide a site where reactants can be brought together to react,thus reducing energy needed for the reaction.-made of proetein

Reactants of enzyme-catalyzed reactions are called _____________________________.Enzymes themselves unchanged in a reactionOften end in –ase/sugars in -oseSubstrates bind to a site on the enzyme called the ______________________________.These are complementary shapes..These are bound together by intermolecular forces making an_______________________________These are bound together until the reaction is done.

2. REGULATION OF ENZYME ACTIVITYAffected by many variables,such as temperature ,pHCells can regulate enzymes in many ways—often w/ a protein that turns the key enzymes on and off.

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