8/13/2019 Chapter 2 Chemical Organization
1/82
The Chemical Level of
Organization
Chapter 2
8/13/2019 Chapter 2 Chemical Organization
2/82
Ch 2 Outline
Atomic structure
Molecules/compounds
Chemical Rxns
Enzymes
Organic vs inorganic
Water properties
pH
Structure & function macromolecules
8/13/2019 Chapter 2 Chemical Organization
3/82
Atoms
Matter- anything that takes up space & has mass Made up of atoms-smallest stable units of matter
Atoms join together to form chemicals with differentcharacteristics
Chemical characteristics determine physiology at
the molecular and cellular levels
8/13/2019 Chapter 2 Chemical Organization
4/82
Atoms Subatomic Particles
Proton Positive charge, 1 mass unit
Neutron
Neutral, 1 mass unit
Electron
Negative charge, low mass
Electrons
Neutrons
Protons
-Change the number of neutrons & electrons-
same characteristics, properties- same atom
-Change the number of protons- different atom!
8/13/2019 Chapter 2 Chemical Organization
5/82
Atomic Structure
Atomic number Number of protons
Equal to number of electrons
Mass number Number of protons plus neutrons
Atomic Number
Atomic Mass
proton
8/13/2019 Chapter 2 Chemical Organization
6/82
Atomic Structure
Nucleus *Contains protons and neutrons
Electron
Cloud*Contains electrons
traveling at high speed
Electrical Force-
negative charge on
electron attracted to
positively charged
protons
8/13/2019 Chapter 2 Chemical Organization
7/82
Elements and Isotopes
Elements-pure substance composed of atoms ofonly 1 kind, uniform composition & properties
Determined by atomic number of atom (protons)
Cannot be broken down or changed
Isotopes-specific version of an element based
on its mass number
Same element, different number of neutrons Only neutrons are different because the number of
protons determines the element
8/13/2019 Chapter 2 Chemical Organization
8/82
8/13/2019 Chapter 2 Chemical Organization
9/82
Isotopes
Same element- different # of neutrons
Atomic number stay same
Atomic mass will differ
Carbonatomic number 6
Carbon 12- _6_ neutrons
Carbon 13- _7_ neutrons
Carbon 14- _8_ neutrons
All have 6 protons! # protons does not change!
8/13/2019 Chapter 2 Chemical Organization
10/82
8/13/2019 Chapter 2 Chemical Organization
11/82
Electrons and Energy Levels
Electrons in the electron cloud determine thereactivityof an atom
Electron cloud contains shells- energy levels
that hold a maximum number of electrons Lower shells fill 1st- closest to nucleus
Outermost shell- valence shell,determines
bonding
8/13/2019 Chapter 2 Chemical Organization
12/82
Energy level- state of potential energy
electrons possess
Correlates to average distance from nucleus Electron shells
Shell 1- closest to nucleus, lowest potential energy
Shell 2- increased energy and so forth
A t f El t i t
8/13/2019 Chapter 2 Chemical Organization
13/82
Arrangement of Electrons into
Energy Levels
Lowest energy shell
Fills first
Can hold two electrons
A t f El t i t
8/13/2019 Chapter 2 Chemical Organization
14/82
Arrangement of Electrons into
Energy Levels
Electrons fill in order, 1stshell,
2ndshell, 3rdshell, etc. moving
away from nucleus.
2nd
shellholds 8
electrons
.
8/13/2019 Chapter 2 Chemical Organization
15/82
Valence Shell
Number of electrons in valence shell determinesthe chemical properties of the element
Atom with unfilled valence shell- unstable
They will react with other atoms to fill their shells!
Atoms with full valence- stable & unreactive
Hydrogen Helium
8/13/2019 Chapter 2 Chemical Organization
16/82
Chemical Bonds
Chemical bonds involve the sharing, gaining,and losing of electrons in the valence shell
Three majors types of chemical bonds
Hydrogen bonds: weak polar bonds based on partialelectrical attractions
Ionic bonds: attraction between cations(electron
donor) and anions(electron acceptor)
Covalent bonds: strong electron bonds involving
shared electrons
8/13/2019 Chapter 2 Chemical Organization
17/82
Chemical Bonds
Chemical bonds form molecules & compounds Molecules-2 or more atoms joined by strong
bonds
Compounds-2 or more atoms of DIFFERENT
ELEMENTSjoined by strong or weak bonds
Compounds are all molecules, but not all
molecules are compounds
H2= molecule only H2O = molecule and compound
8/13/2019 Chapter 2 Chemical Organization
18/82
Ionic Bonds
One atom- electron donor-loses one or moreelectrons and becomes a cation, (positive
charge)
Another atom- electron acceptor-gains those
same electrons, becomes an anion, (negative
charge)
Attraction between the opposite charges then
draws the two ions together
8/13/2019 Chapter 2 Chemical Organization
19/82
Formation of Ionic Bonds
8/13/2019 Chapter 2 Chemical Organization
20/82
Formation of Ionic Bonds
8/13/2019 Chapter 2 Chemical Organization
21/82
Covalent Bonds
Involve the sharing of pairs of electronsbetween atoms
One electron is donated by each atom to
make the pair of electrons Sharing one pair of electrons is a single covalent
bond (strong bond)
Sharing two pairs of electrons is a double
covalent bond (stronger bond)
Sharing three pairs of electrons is a triple
covalent bond (strongest bond)
8/13/2019 Chapter 2 Chemical Organization
22/82
Covalent Bonds
8/13/2019 Chapter 2 Chemical Organization
23/82
Covalent Bonds
Nonpolar covalent bonds- involve equalsharing of electrons
Atoms involved in the bond have equal pull for the
electrons
Polar covalent bonds- involve unequal
sharing of electrons
One of atoms involved in the bond has a
disproportionately strong pull on the electrons
Form polar moleculeslike water
Polar Covalent Bonds and
8/13/2019 Chapter 2 Chemical Organization
24/82
Polar Covalent Bonds and
Water Structure
8/13/2019 Chapter 2 Chemical Organization
25/82
Hydrogen Bonds
Bonds between adjacent molecules, not atoms
Involve slightly positive and slightly negative
portions of polar molecules being attracted to
one another
Hydrogen bondsbetweenH2O molecules
cause surface tension
Hydrogen Bonds between Water
8/13/2019 Chapter 2 Chemical Organization
26/82
Hydrogen Bonds between Water
Molecules
Hydrogen
Bond
8/13/2019 Chapter 2 Chemical Organization
27/82
Chemical Reactions
Reactants- materials going into a reaction
Products- materials coming out of a reaction
Metabolism- all of the reactions that are occurringat one time
Growth, repair, maintenance, energy, secretion,
movement
8/13/2019 Chapter 2 Chemical Organization
28/82
Basic Energy Concepts
Energy- capacity to do work Work- change in mass or distance, (movement
of an object or change in the physical structureof matter)
Kinetic energy- energy of motion
Potential energy- stored energy
Chemical energy- potential energy stored inchemical bonds
8/13/2019 Chapter 2 Chemical Organization
29/82
Energy
Cannot be created or destroyed, only
converted
Conversion between kinetic and potential
energy never 100% efficient
Some energy is always lost as heat
Heat- increase in random molecular motion
8/13/2019 Chapter 2 Chemical Organization
30/82
Chemical Reactions
Decomposition reaction(catabolism) Breaks chemical bonds
ABA + B
Hydrolysis: ABCDE + H2OABCH + HODE
Add water
8/13/2019 Chapter 2 Chemical Organization
31/82
Chemical Reactions
Synthesis reaction(anabolism) Forms chemical bonds
A + BAB
Dehydrationsynthesis (condensation)
ABCH + HODEABCDE + H2O
Lose a water
8/13/2019 Chapter 2 Chemical Organization
32/82
Chemical Reactions
Exchange reaction- involves decomposition first, thensynthesis
AB + CDAD + CB
Reversible reaction-rxn occurs simultaneously inboth directions
ABA + B
At equilibrium amounts of chemicals do not change
even though rxns are still occurring: Seek equilibrium, balancing opposing reaction rates
Add or remove reactants- rxn rates adjust to reach a new
equilibrium
8/13/2019 Chapter 2 Chemical Organization
33/82
Enzymes
Chemical rxns in cells cannot start without help
Activation energy-amount of energy needed to
get a reaction started
Enzymes-protein catalyststhat loweractivation
energy of reactions
Enzyme 1
A B
Reaction 1
Enzyme 2
C
Reaction 2
Enzyme 3
D
Reaction 3
ProductStarting
molecule
8/13/2019 Chapter 2 Chemical Organization
34/82
Effect of Enzymes on Activation Energy
8/13/2019 Chapter 2 Chemical Organization
35/82
Enzymes
Exergonic(exothermic) reactions
Produce more energy than they use
Give off energy
Endergonic (endothermic) reactions
Use more energy than they produce
Require energy to begin
8/13/2019 Chapter 2 Chemical Organization
36/82
Inorganic Vs Organic Compounds
Nutrients-essential molecules obtained from food
Metabolites-molecules made or broken down in the body
Inorganic-molecules not based on carbon and hydrogen
Carbon dioxide, oxygen, water, and inorganic acids,bases, and salts
Organic-molecules based on carbon and hydrogen
Carbohydrates, proteins, lipids, nucleic acids
8/13/2019 Chapter 2 Chemical Organization
37/82
Importance of Water
Water accounts for up to 2/3 of your total body
weight
A solution is a uniform mixture of 2 or more
substances Solute- atoms, ions, or molecules
Solvent- medium, in which solutes are
individually dispersed
Hydrogen bonding between water
molecules accounts for unique properties
8/13/2019 Chapter 2 Chemical Organization
38/82
Properties of Water
Solubility- ability to dissolve a solute in a solventto make a solution (aqueous)
Reactivity- most body chemistry occurs in water
Dehydration, hydrolysis rxns
High heat capacity- ability to absorb and retainheat
Takes a lot of heat liquid
gas, carries great deal ofheat (cooling effect), takes a lot of heat to change temp
Lubrication- to moisten and reduce friction
Knee caps, internal organs
Di i ti f i & l
8/13/2019 Chapter 2 Chemical Organization
39/82
Ionization Dissociation of ions & polarcompounds in water
Polar water molecules formhydration spheres around
ions & small polar molecules
to keep them in solution.
8/13/2019 Chapter 2 Chemical Organization
40/82
Electrolytes & Body Fluids
Electrolytes- inorganic ions that conduct
electricity in solution
Electrolyte imbalanceseriously disturbs vital
body functions
8/13/2019 Chapter 2 Chemical Organization
41/82
Hydrophilic & Hydrophobic Compounds
Hydrophilic hydro- = water, philos = loving
interacts with water
includes ions and polar molecules
Hydrophobic
phobos = fear
does NOT interact with water
includes nonpolar molecules, fats, and oils
http://images.google.com/imgres?imgurl=http://upload.wikimedia.org/wikipedia/commons/thumb/6/67/Stop.svg/500px-Stop.svg.png&imgrefurl=http://commons.wikimedia.org/wiki/Image:Stop.svg&h=500&w=500&sz=28&hl=en&start=2&sig2=PspmeoGJ_4aQ3FwdCkTAWQ&um=1&usg=__v_-4t_zS7J2jmEc2kIdIAMbl-bA=&tbnid=ItmXxJgDK2kHdM:&tbnh=130&tbnw=130&ei=Zhq3SNfiJpvUMJamwY8D&prev=/images?q=stop&um=1&hl=enhttp://images.google.com/imgres?imgurl=http://www.annerpino.com/2003/heart.jpg&imgrefurl=http://tennisplanet.wordpress.com/category/badgood-at-heart-tennis-players/&h=400&w=400&sz=30&hl=en&start=2&sig2=tJqXGAPGjHNbQaIUciNMEg&um=1&usg=__q6DTR1HdzdaNGpRjEGl04Ma-Wi8=&tbnid=PLovHyk9MkQJ3M:&tbnh=124&tbnw=124&ei=SRq3SPO2HZvUMJamwY8D&prev=/images?q=heart&um=1&hl=en8/13/2019 Chapter 2 Chemical Organization
42/82
pH and Homeostasis
pH-concentration of hydrogen ions (H+) in a solution
pH = -log [H+]
Neutral pH: [H+] = [OH-]
A balance of H+and OH
Pure water = 7.0
pH of human blood
Ranges from 7.35 to 7.45
8/13/2019 Chapter 2 Chemical Organization
43/82
pH and Homeostasis
Acidic:pH lower than 7.0
High H+concentration
Low OHconcentration
Basic(or alkaline): pH higher than 7.0 Low H+concentration
High OHconcentration
Acidic Basic
0 147H+> OH- 0H-> H+
[H+] = [OH-]
C
8/13/2019 Chapter 2 Chemical Organization
44/82
pH and Hydrogen Ion Concentration
Inverse relationship: more H+ions mean
lowerpH, less H+ions mean higherpH
A id d B
8/13/2019 Chapter 2 Chemical Organization
45/82
Acids and Bases
Acid-solute that adds hydrogen ions to a solution
Proton donor
Strong acids dissociate completely in solution
HCLH++ Cl-
Base-solute that removes hydrogen ions from a solution
Proton acceptor
Strong bases dissociate completely in solution NaOHNa++ OH-
W k A id /B & S lt
8/13/2019 Chapter 2 Chemical Organization
46/82
Weak Acids/Bases & Salts
Weak acids and weak bases Fail to dissociate completely
Help to balance the pH
H2
CO3
H++ HCO3
-
Salts- solutes that dissociate into cations &anions other than hydrogen ions (H+) and
hydroxide ions (OH-)
B ff d H C t l
8/13/2019 Chapter 2 Chemical Organization
47/82
Buffers and pH Control
Buffers-compounds that stabilize pH of asolution by removing/replacing H+
Weak acid & its related salt compounds
Neutralizes either strong acid or strong base
Sodium bicarbonate is very important in humans
Antacids-basic compound that neutralizes
acid and forms a salt
O i M l l
8/13/2019 Chapter 2 Chemical Organization
48/82
Organic Molecules
Contain H, C, and usually O
Covalently bonded
Contain functional groups that determine
chemistry
Carbohydrates
Lipids Proteins (amino acids)
Nucleic acids
I t t F ti l G
8/13/2019 Chapter 2 Chemical Organization
49/82
Important Functional Groups
*Dont need to
memorize
structure but I
will refer tothese through
out the course
so just
familiarize
yourself with
them if you arenot already.
C b h d t
8/13/2019 Chapter 2 Chemical Organization
50/82
Carbohydrates
Contain C, H, O in 1:2:1 ratio
Monosaccharides
Simple sugars with 3 to 7 carbon atoms
Glucose, fructose, galactose
Disaccharides Two simple sugars condensed by dehydration synthesis
Sucrose, maltose
Polysaccharides Many monosaccharides condensed by dehydration
synthesis
Glycogen, starch, cellulose
P l h id
8/13/2019 Chapter 2 Chemical Organization
51/82
Polysaccharides
Large molecules of complex carbohydrates Straight, highly branched
Structure or energy storage Cellulose-structural component in plants
We cannot digest- fiber!
Starches-storage molecules
Potatoes, grains- main energy source
St t f Gl
8/13/2019 Chapter 2 Chemical Organization
52/82
Structure of Glycogen
Animal starch- glycogenMany side branches of
glucose molecules
Does not dissolved inwater or body fluids
Muscle cells make &
storeBreak it down when
need energy
8/13/2019 Chapter 2 Chemical Organization
53/82
Li id
8/13/2019 Chapter 2 Chemical Organization
54/82
Lipids
Hydrophobic molecules- fats, oils, waxes
Made mostly of carbon and hydrogen atoms
Make up cell membranes, important energy source
Include Fatty acids
Eicosanoids
Glycerides
Steroids
Phospholipids and glycolipids
Lipids Fatt Acids
8/13/2019 Chapter 2 Chemical Organization
55/82
Lipids- Fatty Acids
Long chains of carbon & hydrogen with a
carboxylic acid group (COOH) at one end
Relatively nonpolar- exceptcarboxylic group
Fatty acids may be
Saturatedwith hydrogen (no covalent bonds)
Unsaturated(one or more double bonds): monounsaturated = one double bond
polyunsaturated = two or more double bonds
Fatty Acids
8/13/2019 Chapter 2 Chemical Organization
56/82
Fatty Acids
.
Fatty Acids
8/13/2019 Chapter 2 Chemical Organization
57/82
Fatty Acids
Lipids Eicosanoids
8/13/2019 Chapter 2 Chemical Organization
58/82
Lipids- Eicosanoids
Derived from the fatty acid- arachidonic acid
Leukotrienes- active in immune system (injury
& disease)
Prostaglandins- local hormones, short-chain
fatty acids Pain, tissue damage, trigger labor contractions
Lipids Glycerides
8/13/2019 Chapter 2 Chemical Organization
59/82
Lipids- Glycerides
Fatty acids attached to a glycerol molecule Triglycerides-three fatty-acid tails
Also called triacylglycerols or neutral fats
Three important functions:
energy source
insulation
protection
Lipids Steroids
8/13/2019 Chapter 2 Chemical Organization
60/82
Lipids- Steroids
4 rings of C & H with functional groups
Types of steroids:
Cholesterol:
Component of cell membranes, cell growth & division Estrogens & testosterone:
Sex hormones- regulate sexual function
Corticosteroids & calcitriol: Metabolic regulation, mineral balance
Bile salts: Derived from steroids, process dietary fats
Steroids
8/13/2019 Chapter 2 Chemical Organization
61/82
Steroids
Lipids Phospholipids & Glycolipids
8/13/2019 Chapter 2 Chemical Organization
62/82
Lipids- Phospholipids & Glycolipids
Our bodies can make both from fatty acids
Diglycerides attached to either a phosphate
group (phospholipid) or a sugar (glycolipid)
Generally, both have hydrophilic heads &
hydrophobic tails and are structural lipids,components of cell membranes
8/13/2019 Chapter 2 Chemical Organization
63/82
8/13/2019 Chapter 2 Chemical Organization
64/82
Proteins
8/13/2019 Chapter 2 Chemical Organization
65/82
Proteins
Most abundant organic molecules Contain basic elements: C, H, O, N
Basic building blocks- 20 amino acids
Peptide
bondSide chains
Backbone
7 Major Protein Functions
8/13/2019 Chapter 2 Chemical Organization
66/82
7 Major Protein Functions
Support Structural proteins
Movement
Contractile proteins
Transport
Transport (carrier)
proteins
Buffering Regulation of pH
Metabolic regulation
Enzymes
Coordination &control
Hormones
DefenseAntibodies
Protein Structure
8/13/2019 Chapter 2 Chemical Organization
67/82
Protein Structure
Long chains of amino acids Amino acid structure
Central carbon atom
Hydrogen atom
Amino group
(NH2)
Carboxylic acid group
(COOH)
Variable side chain
R group
Formation of Peptide Bonds
8/13/2019 Chapter 2 Chemical Organization
68/82
Formation of Peptide Bonds
*You should
know a
peptide bond
forms proteins
by joining
amino acids(dehydration
rxn)
Proteins
8/13/2019 Chapter 2 Chemical Organization
69/82
Proteins
Fibrous proteins- structural sheets orstrands
Tough, durable, insoluble in water (structural role)
Globular proteins- soluble spheres withactive functions
Compact, soluble
Protein function is based on shape
Shape is based on sequence of amino acids
Globular & Fibrous Proteins
8/13/2019 Chapter 2 Chemical Organization
70/82
Globular & Fibrous Proteins
Globular protein
Enzyme Function
8/13/2019 Chapter 2 Chemical Organization
71/82
Enzyme Function
Enzymes are catalysts Proteins that lower the activation energy of a
chemical reaction
Are not changed or used up in the reaction
Enzymes are also
Specific- will only work on limited types of substrates
Limited- by their saturation
Regulated- by other cellular chemicals
Enzyme Structure & Function
8/13/2019 Chapter 2 Chemical Organization
72/82
Enzyme Structure & Function
Cofactors & Enzyme Function
8/13/2019 Chapter 2 Chemical Organization
73/82
Cofactors & Enzyme Function
Cofactor- ion or molecule that binds to anenzyme before substrates can bind
Ca2+, Mg2+
Coenzyme- nonprotein organic cofactors
(vitamins)
Isozymes- two enzymes that can catalyze
the same reaction
Glycoproteins and Proteoglycans
8/13/2019 Chapter 2 Chemical Organization
74/82
Glycoproteins and Proteoglycans
Glycoproteins- large protein + smallcarbohydrate
Enzymes, antibodies, hormones, receptors,
mucus production
Proteoglycans-large polysaccharides +
polypeptides
Promote viscosity in tissue fluids
Nucleic Acids
8/13/2019 Chapter 2 Chemical Organization
75/82
Nucleic Acids
Large organic molecules which store and process
information at the molecular level
Deoxyribonucleic Acid (DNA)
Determines inherited characteristics
Directs protein synthesis
Controls enzyme production
Controls metabolism
Ribonucleic Acid (RNA)
Controls intermediate steps in protein synthesis
Structure of Nucleic Acids
8/13/2019 Chapter 2 Chemical Organization
76/82
Structure of Nucleic Acids
DNA and RNA are strings of nucleotides
deoxyribose or ribose
A, G, T, C, or U
Nitrogenous Bases
8/13/2019 Chapter 2 Chemical Organization
77/82
Nitrogenous Bases
PURINES
PYRIMIDINES
Nucleic Acids
8/13/2019 Chapter 2 Chemical Organization
78/82
Nucleic Acids
DNA-double stranded, bases hydrogen bonds tohold double helix together
RNA-single strand
Complementary base pairs: purines pair withpyrimidines
DNA: adenine (A) & thymine (T)
cytosine (C) & guanine (G)
RNA: uracil (U) replaces thymine (T), A & U
8/13/2019 Chapter 2 Chemical Organization
79/82
Structureof
Nucleic
Acids
Types of RNA
8/13/2019 Chapter 2 Chemical Organization
80/82
Types of RNA
Messenger RNA (mRNA)-transcript of DNA
Transfer RNA (tRNA)-
transfers amino acids toribosome
Ribosomal RNA (rRNA)-
forms ribosome whichholds mRNA in place and
aligns tRNA, catalyzing
protein formation
Ribosome
mRNA
tRNA
ATP
8/13/2019 Chapter 2 Chemical Organization
81/82
ATP
Nucleotides can be used to store energy
Adenosine diphosphate (ADP)
Two phosphate groups; di- = 2
Adenosine triphosphate (ATP)
Three phosphate groups; tri- = 3
ATPase-enzyme catalyzes phosphorylation (addition ofa high-energy phosphate group to a molecule)
8/13/2019 Chapter 2 Chemical Organization
82/82
ATP
Top Related