Animal Experiments (in vivo = inside body) (90% fail at this level)
Clinical Trials - Phase I: Tested on healthy human volunteers
Clinical Trials - Phase II: Tested on target population
Cinical Trials - Phase III: Tested on wide variety (age, ethnic groups, and levels of health) all over the country
Cinical Trials - Phase IV: Tested for other possible uses
Maintain stable, constant condition.
Multiple dynamic equilibrium adjustment and regulation mechanisms make homeostasis possible.
Body Temperature = 37C
Blood pH = 7.3 - 7.4
Negative Feedback Loops
The output of the system acts to oppose the input of the system. If overall feed back is negative, system will be stable. Example = maintaining blood pressure
Positive Feedback loop
'A produces more of B which in turn produces more of A'
Examples - Blood Clotting & Contractions during childbirth
Feed Forward Mechanism
Feed-forward control is exemplified by the normal anticipatory regulation of heartbeat in advance of actual physical exertion. Feed-forward control can be likened to learned anticipatory responses to known cues.
Most Common Elements in the Body
Proton: Located in Nucleus. Positive Charge (+). 1 AMU
Neutron: Located in Nucleus. Neutral Charge. 1 AMU
Electron: Located in Orbital. Negative Charge (-). 0 AMU
Atomic Number: Number of Protons
Atomic Mass: Number of protons and Neutrons
Must fill all previous shells first
First orbital holds 2 Electrons
All adjacent orbitals hold 8 Electrons
Outer orbitals are shared.
Organic Molecules bound in this manner.
Non-polar: Equal sharing of Electrons (Example H2)
Polar: Unequal sharing of Electrons (Example H2O)
Transfer of Electrons (Example NaCl)
Atoms seek to stabilize by completing their outer orbitals.
Inorganic molecules typically bond in this manner.
Hydrgoen atoms are slightly attracted to electronegative atoms
Examples: Oxygen, Nitrogen
Found in Protein, Enzymes, and DNA
van der Waals Force
Slight attraction of non-poplar molecules.
Organic Molecules in Biology
Covalent bonds allow for large compounds
Combined with Condensation / Dehydration RXN
Taken apart with Hydrolysis RXN
Carbohydrates / Saccharides
Formula: CnH2nOnMonosaccharides are simple sugars (Glucose)
Two monosaccharides can be joined covalently to form a disaccharide (Glucose + Glucose = Maltose + H2O)
Numerous monosaccharides joined together are called polysaccharides (Glycogen)
Insoluble in polar solvents (water)
Stored in the body as triglyceride.
glycerol + 3 fatty acids = triglyceride + 3 H2O
Palmitic Acid (saturated): single covalent bonds
Linolenic Acid (unsaturated): at least one double bond