Biochemistry Notes Part1

8/8/2019 Biochemistry Notes Part1

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Chemistry of LifeExploring Life Chapter 4

By M. Donohue



Chemistry in Biology???-Biology is¬and all living things are made up of¬.MATTER!

The study of matter and the changes it under goesAre living things changing?

Anything that takes up space (V) and has mass (g)Composed of one or more elements

Pure substance that cannot be broken down intoother substances by chemical meansbasic ingredients of matter; examples gold, helium, oxygen, nitrogen

Substance containing two OR MORE elements chemically combined in a fixed ratioexample: water, sodium chloride (aka table salt)

Smallest possible particle of an element; building block of matter -derived from Greek word atomos which means indivisible

Chemistry

Matter

Atom

Element

Compound

Isotope An alternate form of an element; same # of protons, different number of electrons



Elements

Pure substances About 25 essential elements to life

Trace elements Make up less than 0.01% of body mass but are critical

-Over 100¬92 naturally occurring and the rest are

synthetic/man-

made-made up of 1 type of atom

Iron

Iodine





Some TerminologyChemical S ymbol

One, two or three letters that represent an element on the periodic table (H,

Al, Uuu)

First letter always capitalized, second (and third) ALWAYS lowercase

Doesn·t always have to be the first letter of the name (ex. Fe for Iron, K for

Potassium)

Chemical Formula

Used to represent a COMPOUND (2 or more elements bonded together)

Subscripts indicate the # of atoms of the preceding element inthat

compound

If there is no subscript, it is 1 atom

Ex. H2O, NaCl, C6H12O6

Chemical Equation

Representation of a chemical reaction

R

eactants go in and products come out

2H2 + O2 2 H2O

H2CO3(aq) H2O(l) + CO2(g)



PHYSICAL CHANGE/ PROPER TIES

Color, shape, texture, amount

The actual make-up of matter/substance does NOTchange

Examples

Ripping a piece of paper

Painting a wall

When two substances arecombined to create a newsubstance with new properties

different from those that made itup¬Combo of different elements

Examples

Water H2O

Sodium chloride NaCl

CHEMICAL CHANGE/ PROPER TIES

Compounds

When 2 or more elements are chemically combined in fixed ratios making a new substancewith new properties



Atomic Theory

1) All matter is made of atoms that are

indivisible and indestructible.

2) All atoms of a given element are identical

in mass and properties

3) Compounds are formed by a combinationof two or more different kinds of atoms.

4) A chemical reaction is a rearrangement of

atoms.

Dalton·s Atomic Theory



Proton Neutron Electron

Charge POSITIVE + Neutral 0 NEGATIVE -

Location Nucleus Nucleus Electron cloud

around nucleus

Relative size toeach other

Structure of an Atom-smallest unit of matter that retains properties of element-Atom has an electric charge of zero (all positives equal negatives)



Atomic Number = Number of protons

You can find this on the periodic table(smaller # by the element«goes innumerical order)

In a neutral atom: (charge of 0)# of p+ = # of e- -

Mass Number = the number of

protons and neutrons in the

nucleus of an atom (bigger # on PT)

# of neutrons = mass# - atomic#



Periodic Table TerminologyR ows (go left to right) are called PeriodsColumns (that go up and down) are calledGROUPS or FAMILIESNumber your columns¬1(H),2, skip all the

ones that drop down, 3 (B), 4, 5, 6, 7, 8Families share similar characteristics

Groups of friends have similar interests, act the same

Elements in the same group/family have the SAME

CHEMICAL PRO

PERTIES They react the same!!



Opposites attract¬+protonsattract -electrons and hold themin place in the electron cloud

Electrons are arranged in´orbitalsµ around the nucleus

First orbital / ring has a maximumcapacity for 2 electrons

Each ring after has a MAXCapacity for 8 electrons

VALENCE electrons are the onesin the outer most ring!

Columns of the periodictable tell you how manyvalence electrons there are





1. GOLD2.POTASSIUM3.XENON4. GER MANIUM5. TUNGSTEN

For each of the following, determine:a. Atomic Numberb. Mass Numberc. Number of Protonsd. Number of Electronse. Number of neutrons



Chemical R eactivityAbility of one substance to combine with anothersubstance and form a new substance

***ELECTRONS*** determinechemical reactivity

With the EXCEPTIO

N of Heand H (why do you thinkthey are by themselves), allatoms want to try and have8 Valence (outer) electrons

H and He only need 2 to behappy

8 valence e- =

2 v.e. = for H and He

Time to play..theR INGS!!!



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Biochemistry Notes Part1