Key Concepts
 Inorganic chemistry review
 Molecular bonds and shapes
 Biomolecules
 pH and buffers
 Protein interactions
Element = Building block of matter
Contains only atoms with same # of protons
 Periodic Table of the Elements
 In human: 11 major essential elements
CHNOPS ? MgKCaFe – rest trace elements
Structure of
Atoms (“indivisible”)
Subatomic particles:
Compare
to Fig 2-1
•
•
•
•
Atomic #
Atomic mass
Ion
Isotope
Isotopes
Much rarer isotopes:
Most common
Much rarer
Heavy water = ?
Some isotopes are unstable:
Radioisotopes
3 types of radiation:
1.  radiation
2.  radiation
Particle emission  Atom
converted to different element
3. radiation: high energy waves, not
particles
More stable
atom of same
element
Nuclear Medicine: use of radioisotopes in
diagnosis & treatment of disease.
131I
 and  radiation
Medical
Imaging ?
Importance of Electrons in Physiology
• Ion formation
• Bond formation between atoms 
molecules
– Covalent vs. ionic vs. H-bonding
• Energy capture & transfer
• Free radical formation and antioxidants
Molecular Bonds and Shapes
• Covalent bonds
–Polar vs. nonpolar
• Ionic bonds
• Hydrogen bonds
• Van der Waals forces
Covalent Reaction: Water

Some nuclei have stronger
attraction for shared ethan others. Why?

Polar covalent
molecule
Non-polar covalent
molecules
Consequence: ions and polar
molecules dissolve well in
water
The 3 steps of Ionic
Bonding
Fig 2-4
Important Ions in Physiology
What for ?
Table 2-1
cations
anions
H-bonds
= weak attraction between H
and nearby O, N or F.
Critical for protein structure
Hydrogen bonding of H2O leads
to important characteristics:
Liquid at RT
Universal solvent for polar molecules
Temp. buffer / frozen water less dense
Capillary action
Surface tension
Biomolecules
Organic molecules associated with living
organisms
1)
2)
3)
4)
2 common features of biomolecules ?
Functional Groups
= partial
molecules.
Frequently occur
in biological
molecules.
Moved around as a
single units.
Table 2-2
Carbohydrates
See Fig 2-7
• Basic formula ? (see name!)
• Monosaccharides
– examples ??
• Disaccharides
= simple sugars
– examples ??
• Polysaccharides
– examples ??
= complex COHs
Lipids
See Fig 2-8
• Most diverse group of biomolecules
• Dissolve in . . .?
• Contain much less O2 than COHs
• 4 categories:
 ____________________ can be (un)saturated
 ____________________
 ____________________
 Eicosanoids (prostaglandins et al.)
 Functions?
Cholesterol decreases
cell membrane
permeability to small
water-soluble
molecules.
Function?
Names of the 2
functional groups ?
Proteins
• Made up of ____?
• Peptide → oligopeptide → polypeptide → protein
• Most versatile of biomolecules in structure and
function → cell’s workhorses
Combination Molecules
• Lipoproteins
cell membrane components,
carriers for hydrophobic
molecules (e.g.?)
• Glycoproteins
• Glycolipids
structure and stability,
receptors, markers)
Nucleotides and Nucleic Acids
• A–C–G–T–U
• ATP, ADP, cAMP, FAD,
NAD
• Differences of DNA and
RNA
• Function
– information storage
– info and energy
transmission
Some Nucleotides are Involved in
Energy Transfer
ATP
ADP
NAD & FAD
or
Info Transfer
cAMP
Aqueous solutions and concentrations
will be covered in lab. Refer to the
textbook when doing the lab exercises
Acids, Bases and Buffers
pH: Expression for H+ ion concentration
In other words: [H+] determines pH and
thereby body’s acidity or alkalinity
Buffers
• Molecules that prevent large pH changes
• Important for pH homeostasis in body
• HCO3- is important buffer in human body
bicarbonate
Equation for adding hydrochloric acid to sodiumbicarbonate ?
Acidosis vs. Alkalosis
Our textbook (Ch20):
Acidosis <7.38
Our textbook (Ch20):
Alkalosis >7.42
Genomics vs. proteomics
Insoluble proteins → structure
Soluble proteins →
Protein
Interaction
1. _____________
2. _____________
3. Signal molecules
4. _____________
5. Binding proteins
6. Regulatory proteins
7. ______________
Protein Binding
• Ligand
• Selective binding (varying degrees
Fig 2-16
of specificity) → induced fit model
of protein-ligand interaction
• Competition if several ligands interact with
one protein
• Affinity
• Reversible binding reactions lead to
equilibrium
• Competition → agonists and antagonists
Multiple Factors Alter Protein Binding
Binding affinity is modulated
• Isoforms (e.g.: hemoglobin)
Figs 2-17/18
• Proteolytic activation and cofactors
• Chemical modulation through activators
or inhibitors (antagonists)
– Competitive inhibition
(reversible or irreversible)
– Allosteric modulation
– Covalent modulation
Fig 2-19
Fig 2-20
Protein Amount and Reaction Rate
• Up- and down-regulation of protein
amount in cell
• At saturation → reaction rate reaches
maximum
Figs 2-22/23