1. Unit 2: Basic Chemistry

2. Chemistry, as a science, boils down to two basic concepts……
Matter & Energy

3. Matter: Anything that takes up space and has mass
Mass is a measurement
of matter
Weight is the pull of gravity on an object

4. Three (4) States of Matter
Solid – defined volume
and shape
Liquid – defined volume
with no definite
shape
Gas – no definite volume
or shape
Plasma - no definite
volume or shape;
only exist at
extremely high
temps (sun)

5. Energy: The ability to do work; the ability to put matter into motion.
Forms of Energy include:
Light, heat, chemical, electrical, mechanical

6. Energy Conversions
In biology, organisms typically convert energy from one form into another.
This is metabolism !!!!
Metabolism
1.) the sum total of the chemical
processes that occur in living
organisms, resulting in growth,
production of energy, elimination
of waste material, etc.
2.) the sum total of the chemical
processes affecting a particular
substance in the body

7. Plants convert light energy to chemical energy (photosynthesis)

8. 2. Animals convert chemical energy (food)
into heat and mechanical energy
Chemical Energy
Mechanical Energy

9. Where does the energy all come from ?
The sun is the ultimate source of energy.
Plants directly utilize the energy from the sun and then pass stored energy from one organism to the next through eating relationships (Food Chain)

10. Types of Energy Potential: Stored energy; not being used at the time.
Kinetic Energy: Energy being used or
released (energy of motion)

11. So what is Chemistry and why do we study it in Biology ?
It’s a study of the relationship between matter and energy.
Life doesn’t exist without chemistry.
Living things are nothing more than extremely well organized, highly complex, precisely arranged atoms.

12. Atoms The smallest, most basic unit of matter
Too small to be seen; many theory-based models have been developed to show their structure and properties

13. The Basic Atom + - Proton Neutron No Charge Electron nucleus
AMU
Neutron
No Charge
AMU
Electron -
Moving around in orbitals, clouds, or shells
AMU;
not usually considered in the mass of an atom

14. Elements Elements: are pure substances which could
not be chemically broken down
into simpler kinds of matter.
More than 100 exist
Only 30 are important to living things

15. The Periodic Table
All the elements are arranged on a chart known as the periodic table

16. Each Element Box Atomic Number = # of Protons
(this is what makes one element different from another)
Atomic Mass = Protons + Neutrons
(Atomic Weight, Mass Number)
Symbol: One or two letter abbreviation
Grammar: 1st Letter Capitalized; 2nd letter lowercase if present
Symbols based in Latin

17. So, in stable, neutral atoms…
The # of protons = The # of electrons
(The positive particles = The negative particles)
The # of protons = the atomic number
The # of electrons = the # of protons
The # of neutrons = Mass # - # of Protons
Let’s see if we got this straight ……….

18. What is the:
Atomic number? _____
Amu? _____
Number of protons? ____
Number of electrons? ____
Number of neutrons? ____
What is the:
Atomic number? _____
Amu? _____
Number of protons? ____
Number of electrons? ____
Number of neutrons? ____

19. Ions Ions are charged atoms due to a loss or gain of electrons
Ions are not neutral atoms; they have totally different chemical properties than their stable atom counterpart.
Cation: a positively charged atom
Anion: a negatively charged atom

20. (One more proton than electron)
Cation:
Positively charged ion due to a loss of electrons.
For example…
A neutral sodium atom has 11 electron
A sodium ion (cation) only has 10 electrons
Therefore a sodium ion has a +1 Charge
(One more proton than electron)

21. (One more electron than proton)
Anion:
Negatively charged ion due to a gain of electrons.
For example ….
A Chlorine atom has 17 electrons
A Chlorine (ion) anion has 18 electrons
Therefore a chlorine ion has a -1 Charge
(One more electron than proton)

22. Isotopes
Different forms of the same atom due to an unstable nucleus with extra neutrons.
Therefore, isotopes usually have a greater atomic mass than normal stable atoms.
E.g. Carbon Isotopes
Carbon typically has a mass of 12 (6P + 6N)
Carbon 14 is an isotope of Carbon that has a mass of 14
(6P + 8N)
C14 is used to date fossils

23. Radioisotopes Most isotopes are radioisotopes
Over time, the extra neutrons are lost from the nucleus as a form of radiation over time.
Others: Uranium & Plutonium are used in
nuclear energy

24. Biological Elements
Most elements DO NOT exist in their “pure atomic elemental state”
Most combine with other elements to form molecules & compounds.
Oxygen Calcium Sodium Iodine
Carbon Phosphorus Chlorine
Hydrogen Potassium Magnesium
Nitrogen Sulfur Iron

25. Oxygen - O Carbon - C Hydrogen - H Nitrogen - N Calcium - Ca Iron - Fe
Required for cellular respiration – the breakdown of glucose to produce energy
Carbon - C
Key element in all organic compounds (made by living things)
Hydrogen - H
Influences the acidity of body fluids (pH)
pH = potential to attract hydrogen ions
Nitrogen - N
Key element in Proteins and DNA
Calcium - Ca
Responsible for strong skeletons and teeth
Iron - Fe
Found in hemoglobin (blood): carries oxygen

26. Phosphorus - P Potassium - K Sulfur - S Sodium - Na Chlorine - Cl
Part of the high energy compound ATP
Potassium - K
Ions necessary for proper muscle contractions
Sulfur - S
Found in muscle proteins
Sodium - Na
Major extra-cellular cation (salt)
Chlorine - Cl
Major extra-cellular anion (salt)
Magnesium - Mg
Important for proper metabolic reactions
Iodine - I
Goiter
Needed for proper thyroid functioning

27. Compounds
Most elements do not exist by themselves; will combine with other elements.
Compounds are two or more different elements chemically combined

28. Properties of Compounds
Compounds are much different than the elements that compose them
Sodium in water
But yet, Sodium Chloride = Salt

29. Molecules – but not compounds
Form from the covalent bonding of atoms (could be like atoms); or the simplest part of a compound
Examples:
NaCl
H2O
Molecules – but not compounds

30. Chemical Formulas Chlorophyll
Uses the symbols and the proportion of each atom that makes up the compound
H2O: Two hydrogen atoms and one oxygen atom combine to make water
Can you guess what compound has this chemical formula? C55H72O5N4Mg
Chlorophyll

31. Ions: Symbolized by raised charges
Coefficients
Used in front of formulas to indicate how many molecules
Example: 2H2O = 2 water molecules
Ions: Symbolized by raised charges
Examples:
Na+ = Sodium plus 1 ion
Ca+2 = Calcium plus 2 ion

32. Physical Properties of Matter
Observable changes in matter that do not change the chemical properties of the matter
Color, shape, phase, texture, size, etc..
Chemical Properties of Matter
Observable changes in matter that change the chemical properties of the matter
New pieces of matter are created during a
chemical reaction – Usually non-reversible
by normal means

33. Chemical Reactions C6H12O6 + O2 CO2 + H2O Reactants Products
Two of more substances called reactants characterized by a chemical change and yielding one or more products which are different from the reactants.
C6H12O O CO2 + H2O
Reactants Products

34. Exothermic Reaction Endothermic Reaction
Energy is given off from the chemical reaction (will see a temperature increase)
Endothermic Reaction
Energy is absorbed from the chemical reaction (will see a temperature decrease)
A common example is a chemical ice pack, which usually contains water and a packet of ammonium chloride

35. Chemical Bonding
Occurs when an atoms chemical properties are not stable
Most elements rarely exist by themselves
The number and arrangement of electrons in an atom determines if it will combine to form compounds

36. Atomic Models 1st shell: full and stable with 2 electrons
2nd shell: 8, 3rd shell : 8, 4th shell: 8
Octet Rule: Electron shells are stable with 8
electrons (except the 1st)
Any element atom that does not meet the outer shell electron requirements will chemically bond with another atom
Electrons in the outer shell are called valence electrons

37. Examples… Oxygen: Carbon: 6 Protons 8 Protons 6 Neutrons 8 Neutrons
6 Electrons
2 in the 1st shell, 4 in the second shell (valence)
8 Protons
8 Neutrons
8 Electrons
2 in the 1st shell, 6 in the second shell (valence)

38. An easy way to figure valence shell electrons ….
Use Periodic Table: Columns are arranged to indicate similarities in chemical properties; The column number = the number of valence electrons

39. All elements in column one = 1 valence electron 3 4 5 6 7 8 2
All elements in column one = 1 valence electron
All elements in column two = 2 valence electrons
And so on…..
Column eight = inert gases (non-reactive)

40. 1st Shell Two electrons Two elements
How it works 1:
Periods are rows / represent shells
1st Shell Two electrons Two elements
2nd Shell Eight electrons Eight elements
3rd Shell Eight electrons Eight elements
4th Shell Eighteen electrons Eighteen elements

41. “Families” hint at basic chemical behavior
How it works 2:
“Families” hint at basic chemical behavior
Elements in these columns generally have little role in living things
Elements in this column generally SHARE four electrons
Elements in this column GIVE / LOSE one electron
Elements in this column generally SHARE three electrons
Elements in this column TAKE / GAIN two electrons
Elements in this column TAKE / GAIN one electron
Elements in this column have a FULL outer shell They do NOTHING. (inert)
Elements in this column GIVE / LOSE two electrons

42. 1. Ionic Bonding Occurs between positive and negative ions
Formed when one or more electrons are transferred from one atom to another
Example: Salt - NaCl

43. Ionic Bonds
Are relatively weak bonds
Do not contain much energy

44. 2. Covalent Bonds
Form between atoms that will share one or more pairs of electrons
Example: Water – H2O
Results in the formation of molecules
Strong bonds – contain much stored energy

45. Mixtures General properties of a mixture: Types of Mixtures
A mixture is made when two or more substances are combined, but they are not combined chemically.
General properties of a mixture:
The components of a mixture can be easily separated.
The components each keep their original properties
The proportion of the components is variable
Types of Mixtures
There are two main categories of mixtures: homogeneous mixtures and heterogeneous mixtures. In a homogenous mixture all the substances are evenly distributed throughout the mixture (salt water, air, blood). In a heterogeneous mixture the substances are not evenly distributed (chocolate chip cookies, pizza, rocks)

46. 1. Solutions
A mixture in which one or more substances are uniformly distributed into another
Can be solids, liquids, gases
Solute: the substance dissolved
Solvent: The substance in which the solute is dissolved
Water = Universal Solvent

47. An example of a solution: Sugar in Water
Sugar = Solute
Water = Solvent
Though the sugar dissolves in water, neither of the molecules are changed chemically

48. Solution Characteristics
Typically clear
Concentration = amount of solute dissolved
into a fixed amount of solvent
Saturated Solutions = No more
solute can be
dissolved

49. 2. Suspension
Mixture in which substances are typically larger, and do not readily dissolve.
The substances will temporarily mix but, will settle out over time
Are typically cloudy
at first

50. 3. Colloid In-between solution and suspensions
Definition: a homogeneous substance consisting of particles of one substance dispersed through a second substance. Colloids include gels, sols, and emulsions; the particles do not settle and cannot be separated out by ordinary filtering or centrifuging like those in a suspension.
In-between solution and suspensions
Milk, Jell-O and Cytoplasm common examples