1. Unit 3: The Chemistry of Life
The study of matter &
the changes it undergoes.
Unit 3: The Chemistry of Life
Chapter 3: Matter & Energy

2. Matter & It’s Combinations: Matter (sec. 3.1)
What is matter?
anything that has mass & volume
What is matter made of?
elements
Mass = amount of substance (NOT weight… weight includes the effect of gravity)
Volume = amount of space taken up by substance

3. Matter & It’s Combinations: Elements
What is an element?
a substance made of only one type of atom & can’t be broken into simpler substances
ex. = carbon, hydrogen, nitrogen, oxygen, phosphorous, sulfur, etc.
What are elements made of?
atoms
What is an element? substance that is made of only one type of atom, can’t be broken into simpler substances by ordinary chemical means Examples: CHNOPS
What are elements made of? atoms

4. What are the 6 Most Abundant Elements in Biological Matter?
CHNOPS makes up 99% of mass of ALL living things
Along w/ CHNOPS… Ca & K make up the 8 most abundant elements in the HUMAN body…

5. Matter & It’s Combinations: Atoms
What is an atom?
smallest part of an element that has all the element’s chemical & physical properties
ex. carbon, hydrogen, nitrogen, oxygen, phosphorous, sulfur, etc.
What are atoms? Atoms are the smallest part of an element that has all the element’s chemical & physical properties Examples =oxygen, carbon, nitrogen, hydrogen, silicon, gold Represented by a symbol (as well as name)

6. What Makes Up an Atom? subatomic particle location charge symbol
proton
nucleus (center of atom)
positive p+
neutron
neutral
(no charge) n0
electron
orbit around nucleus (located in energy levels)
negative e-
17 p+
18 n0
Central region called the nucleus Consists of: protons, p positive charges (determines element & its properties) neutrons, n0 (neutral/no charge),
Most of the mass of an atom (p = 1 amu n = 1 amu, about amu heavier than proton)
Electrons, e Negatively charged particles orbit around nucleus, Located in discrete energy levels = shells Often called electron “cloud” (outer most = valence shell) smallest part of atom amu
In its neutral state, an atom has an equal number of protons and electrons…so, it has no charge.

7. Matter & It’s Combinations: Atoms
Atoms found in their neutral state have no charge.
Why?
equal # of protons & electrons
What would happen if an atom:
gained an electron?
negative charge
lost an electron?
positive charge
What do we call an atom that has a charge?
ion
17 p+
18 n0
Central region called the nucleus Consists of: protons, p positive charges neutrons, n0 (neutral/no charge),
Most of the mass of an atom (p = 1 amu n = 1 amu, about amu heavier than proton)
Electrons, e Negatively charged particles orbit around nucleus, Located in discrete energy levels = shells Often called electron “cloud” (outer most = valence shell) smallest part of atom amu
In its neutral state, an atom has an equal number of protons and electrons…so, it has no charge.

8. Matter & It’s Combinations: Atoms
How do we classify atoms?
The Periodic Table
families (groups)
columns
elements have similar chemical properties b/c same # of valence electron
periods
rows
# of protons & electrons increases (+1 as move left to right)… filling up outer energy level
periodic table = tool used to organize info about the elements. Shows atomic number (# protons) and atomic mass (# protons + neutrons). Families (groups) vertical (up and down) columns elements have similar chemical properties. Same # of valence electrons
Periods rows from left to right # of protons & electrons increases (by 1 each time you move from left to right filling up outer energy (valence) level

9. Using the Periodic Table of the Elements to Determine Atomic Structure
# of protons (determines element & its properties) 16
also # of electrons
bigger of the 2 #s
periodic table = tool used to organize info about the elements. Shows atomic number (# protons) and atomic mass (# protons + neutrons).
Atomic number: number of protons in nucleus (Because atoms are neutral: # electrons = # protons)
Determines the element & its properties Atoms of the same element always have the same atomic number
Atomic Mass: total mass of protons and neutrons within an atom’s nucleus (bigger of the 2 numbers)
To figure out # of neutrons…
atomic mass – atomic number = neutrons
protons + neutrons

10. Bohr Model of Atomic Structure
# protons (+) equals # electrons (-) Electrons in shells
# of valence electrons determines type of bonding
argon
outermost (valence) shell

11. Atomic Structure: Electrons & Energy Levels
electrons in energy levels (“shells”) around nucleus
1st shell  holds up to 2 electrons
other shells  up to 8 electrons (fill before go to next) Na
17 p+
18 n0
As the # of electrons in atoms increases, more energy levels are needed to hold them. Each level can hold only a specific number of electrons.
1st  nd  rd  8
For Na (sodium), how many more electrons can the 3rd shell hold? Seven more
How many more electrons can the 3rd shell hold?

12. What Affects the Bonding of Atoms?
# of valence electrons
If valence level is:
not full
atom is unstable
& will bond with electrons from other atom(s) to fill outer level (by sharing, gaining, or losing)
full
atom is stable
& won’t bond
# of electrons in outermost (valence) shell governs bonding behavior
Some atoms already have full valence energy levels (& are stable) do not readily combine with other elements to form compounds
If not full, stability can be achieved by forming bonds with other atoms by gaining, losing, or sharing electrons.
3 main bond types: covalent ionic metallic

13. What is a Covalent Bond? atoms are held together by shared electrons
2+ atoms share electrons to form a compound single pair shared = single covalent bond pairs shared = double covalent bond
A water molecule is made up of two hydrogen atoms and one oxygen atom. Oxygen is in the 6th column of the periodic table so we know it has 6 electrons in its outermost shell.
To be balanced Oxygen needs to gain two electrons or lose six. Hydrogen needs to gain one electron to be balanced. Each hydrogen can form a covalent bond and share its electron.

14. What is an Ionic Bond?
Atoms & Bonding Interactive
atoms are held together when they lose or gain electrons
oppositely charged ions attract forming compounds
Ex. Na+ & Cl-  NaCl (table salt)
held together when atoms lose or gain electrons charged atom = ion lose  positive gain  negative
opposite charges attract forming compounds (salts) Ex. NaCl (table salt)
The number of positive or negative charges on an ion is shown as a superscript after the symbol for an atom or group of atoms
Hydrogen ions (H+), Hydroxide ions (OH-) Sodium ions (Na+), Chloride ions (Cl-)

15. What are Molecules/Compounds?
combinations of 2 or more atoms bonded together
ex. = O2, H20, C6H12O6, NaCl, HCl, C6H12O6
What is a molecule? Combination of 2 or more atoms are joined by a covalent bond Examples… oxygen O2, hydrogen H2, water H2O
Compounds substance with two or more atoms of different elements combined chemically; Elements combine in a fixed proportion (Can have properties unlike those of the elements from which it is made)
Examples water 2 hydrogen and 1 oxygen table salt 1 sodium and 1 chlorine sucrose

16. Chemical Formulas & Equations
tell kinds & #s of atoms in one molecule of substance
shown with subscripts
Ex. H2O
chemical equations
represent chemical reactions
coefficients
Ex. 2Mg + O MgO
(yields)
Formula Tell kinds and numbers of atoms in one molecule (or smallest unit) of a substance
Subscripts tell the number of atoms of the element to the upper left (of the subscript). Ex. H2O Tells us 2 atoms of H & 1 of O in one molecule of water (if no subscript, then it is understood to be 1)
Chemical Equations Represent chemical reactions, obey the law of conservation of matter –what goes in must come out
Coefficients tell how many of the molecules they precede are involved Eg. 2Mg + O2  2MgO Read as magnesium plus oxygen yields magnesium oxide Substances to the left of the arrow are reactants, and substances to the right are products
In this reaction, 2 atoms of magnesium react with 2 atoms of oxygen to produce 2 molecules of magnesium oxide.

17. Hydrogen Ions Determine pH
pH  concentration of H+ ions in a solution
expressed as 1.0 x 10-x
(absolute value of) exponent tells pH
scale: , quantifies acidity of solutions.
acid  pH <7
neutral pH = 7
base  pH >7
pH  concentration of H+ ions in a solution Expressed as 1.0 x 10-x exponent tells pH value Ex. A substance with a pH of 7 has an [H+] of 1.0 x 10-7
The pH scale ranges from 0 to 14 and quantifies the acidity of solutions
Acidic solutions have a pH less than Lower pH = higher concentration of H+ (lower concentration of OH-), greater the acidity
Basic solutions have a pH greater than Higher pH = higher concentration of OH- (lower H+), greater the alkalinity (base)
Neutral solutions have a pH of (ex. pure water)
For every increase in pH value, the concentration of H+ ions increases tenfold.
Ex. A substance with pH of 6 contains 10 times as many hydrogen ions as a substance with pH of 7
Organisms – and tissues within organisms have specific pH requirements
Copyright C Pearson Education, Inc., publishing as Benjamin Cummings

18. Biological Chemistry (sec. 3.2)
inorganic molecules
simple structure
H20, 02, NH3, CO2
inorganic even though it contains carbon
an exception to the rule

19. Biological Chemistry organic molecules contain: carbon
& usually hydrogen
complex structure
Carbon has 6 electrons (4 in the valence shell), needs 4 more electrons, usually forms covalent bonds… not only can it bond w/ different elements, but can also bond w/ other carbon atoms, which explains why C-compounds can be so complex

20. Biological Chemistry: Monomers & Polymers
What is a monomer?
small molecule
What is a polymer?
large molecule made of repeated monomers

21. What are the 4 major types of organic biological macromolecules?
amino acid polypeptide (protein)
nucleotide nucleic acid (DNA & RNA)
monosaccharide polysaccharide
fatty acids & glycerol Lipid
carbohydrates
lipids (fats)
proteins
nucleic acids

22. Carbohydrates monomer = monosaccharides polymer = polysaccharides
simple sugars
All have same empirical formula CH2O
C6H12O6  glucose
polymer = polysaccharides
starches, cellulose
sugar
cellulose
starch
major source of energy (& energy storage) in the body
Contain C,H,O in a ratio of 1:2: Ratio of H:O is 2:1 just like H2O Ex. C6H12O6
Monomer = Monosaccharides All have the same empirical formula CH2O C6H12O6  glucose
Polymer = some sugars (disaccharides), Starches, Cellulose
Formed by dehydration synthesis of monosaccharides
Isomers are molecules with the same formula, but have different molecular structures.
monosaccharide + monosaccharide
disaccharide

23. Functions of Carbohydrates
energy source, energy storage, support (plant cell walls)
cellulose
major source of energy (& energy storage) in the body
Contain C,H,O in a ratio of 1:2: Ratio of H:O is 2:1 just like H2O Ex. C6H12O6
Monomer = Monosaccharides All have the same empirical formula CH2O C6H12O6  glucose
Polymer = some sugars (disaccharides), Starches, Cellulose
Formed by dehydration synthesis of monosaccharides
Isomers are molecules with the same formula, but have different molecular structures.

24. Lipids oil fat building blocks (not monomers) = fatty acids & glycerol
lipid (fat) molecule = triglyceride
Building blocks (not monomers) = fatty acids & glycerol
Long-term energy storage, cell membrane, hormones, insulation, nerve transmission
Formed by dehydration synthesis of glycerol & fatty acids
Forms the letter E

25. Functions of Lipids
long-term energy storage, cell membrane, hormones, insulation, nerve transmission
Building blocks (not monomers) = fatty acids & glycerol
Long-term energy storage, cell membrane, hormones, insulation, nerve transmission
Formed by dehydration synthesis of glycerol & fatty acids
Forms the letter E

26. Saturated vs. Unsaturated Fats
unsaturated has double bonds
saturated has only single bonds
Saturated (animal fats) Consist of SINGLE bonds…has the maximum number of hydrogens bonded to the carbons, and therefore is "saturated" with hydrogen atoms. room temp)
Unsaturated (plant fats) Consist Of at least 1 DOUBLE bond… doesn’t have max # of hydrogens bonded to the carbons, & therefore is “unsaturated” w/ H atoms room temp)
In cellular metabolism, unsaturated fat molecules contain somewhat less energy (i.e., fewer calories) than an equivalent amount of saturated fat. …healthier

27. Proteins monomer = amino acid polymer = polypeptide/protein
meat,/ fish/ eggs/ nuts/ beans
monomer = amino acid
amino group  NH2
acid group  -COOH
“variable”/replaceable group  R
polymer = polypeptide/protein
muscle
Amino Acids = Building blocks of (polypeptides & then) proteins
AA have a central carbon atom which is attached to a hydrogen atom, an amine group (-NH2), a carboxyl acid group (-COOH), and a Variable/replaceable group (R)  R: one of 20 different atoms or group of atoms
There are 20 different types of amino acids found in the natural world.
proteins make up muscle, enzymes, hormones, meats/fish/eggs/nuts/beans
Enzymes make reactions happen
Protein function is dependent on structure
hormone

28. There are 20 different amino acids found in the natural world.

29. Functions of Proteins
structure, enzymes, transport materials in & out of cells, hormones, muscle
hormone
muscle
Amino Acids = Building blocks of (polypeptides & then) proteins
AA have a central carbon atom which is attached to a hydrogen atom, an amine group (-NH2), a carboxyl acid group (-COOH), and a Variable/replaceable group (R)  R: one of 20 different atoms or group of atoms
There are 20 different types of amino acids found in the natural world.
proteins make up muscle, enzymes, hormones, meats/fish/eggs/nuts/beans
Enzymes make reactions happen
Protein function is dependent on structure

30. Nucleic Acids monomers = nucleotides polymers = nucleic acids
(entire structure)
monomers = nucleotides
sugar-phosphate backbone
nitrogenous bases
DNA = Adenine, Thymine,
Cytosine, Guanine
RNA = Uracil (instead of Thymine)
polymers = nucleic acids
DNA & RNA
Monomers = nucleotides made of sugar-phosphate backbone & 1 of 4 nitrogenous bases (In DNA… Adenine, Thymine, Cytosine, Guanine & in RNA… Uracil instead of Thymine)
Polymers = nucleic acids (DNA & RNA)
DNA = Deoxyribonucleic Acid
Stores info for putting amino acids together to make proteins
The basis of genes & heredity
RNA = Ribonucleic Acid
Helps to synthesize (build) proteins
Why do living things need DNA? so they can pass on genetic code & continue the species

31. Functions of Nucleic Acids
DNA = Deoxyribonucleic Acid
genetic “blueprint”
RNA = Ribonucleic Acid
helps to synthesize proteins
Why do living things need DNA?
So they can pass on genetic code & continue the species.
Monomers = nucleotides made of sugar-phosphate backbone & 1 of 4 nitrogenous bases (In DNA… Adenine, Thymine, Cytosine, Guanine & in RNA… Uracil instead of Thymine)
Polymers = nucleic acids (DNA & RNA)
DNA = Deoxyribonucleic Acid
Stores info for putting amino acids together to make proteins
The basis of genes & heredity
RNA = Ribonucleic Acid
Helps to synthesize (build) proteins
Why do living things need DNA? so they can pass on genetic code & continue the species

32. Organic Biological Macromolecules
Elements Contained
Monomer
(building blocks)
Polymer
Function
carbohydrates
(sugar, starch, cellulose)
C, H, O
Ratio 1 : 2 : 1
monosaccharide
(simple sugars such as glucose)
polysaccharide (such as starch & cellulose)
Energy source, energy reserve, plant cell walls
lipids
(fats, oils, & waxes)
(# of H is much greater than # of O)
Fatty acids &
Glycerol
(Built from 2 types of simpler molecules… NOT monomers.)
Not applicable
Energy reserves, cell membrane, hormones, insulation, nerve transmission
protein
C, H, O, N, S
Amino acids
(20 different A.A.)
polypeptides (proteins)
Structure, enzymes, transport materials in & out of cells hormones, muscle
nucleic Acids
(DNA & RNA)
C, H, O, N, P
Nucleotides
(sugar-phosphate backbone & nitrogenous bases)
nucleic acids (DNA & RNA)
Carries genetic code (“blueprint for organism) & directs protein synthesis
A monomer is a molecule that is able to bond in long chains.
Polymer means many monomers. Sometimes polymers are also known as macromolecules or large-sized molecules. Usually, polymers are organic (but not necessarily).
Enzymes are catalysts & help reactions occur