Fundamental Human Physiology Lecture 1

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Fundamental Human Physiology Lecture 1
2012-01-20 19:58:21
Fundamental Human Physiology

Notes from lecture 1
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  1. What do we mean by Physiology?
    • Study of functions of living things
    • Physiology emphasizes mechanisms
    • Structure­â€Function relationships of the body
  2. Homeostasis
    • Maintenance of a relatively stable internal environment
    • Essentials for survival and function for all cells and organism
    • The purpose of physiological processes taking place is to maintain homeostasis
  3. How do physiological systems act to maintain
    • Sensor - detects deviation in a condition away from a specifc level (set point)
    • Integrating Center - controls the activity of the effector(s) base on input from the center(s)
    • Effector - affects the environmental condition (usually compensating for some deviation)
  4. Feedback
    return of output from a regulatory mechanism into the input part of that system
  5. Types of Feedback
    • Negative Feedback loop
    • Positive Feedback loop
  6. Negative Feedback loop
    • change in a condition leads to a response which counteracts that change
    • – Most common type of physiological response
  7. Positive Feedback loop
    • change in a condition leads to a response which amplifies that change
    • – Subsequent output from the effector is increased as condition is pushed further away from the set point
  8. What are the parts of an atom?
    • Protons
    • Neutrons
    • Electorns
  9. Nucleus
    Contain protons and neutrons
  10. Atomic number
    • # of protons in an atom
    • Defines the element (basic type of atom)
  11. Atomic mass
    • Average total # of protons and neutorns in atoms of an element
    • Number of neutrons can vary among atoms of the same element
  12. Isotopes
    Atoms of the same element that have different atomic masses
  13. Valence electrons
    • electrons in the outer shells
    • Participate in chemical reactions
  14. Chemical reaction
    An event where groups of atoms redistribute electrons among them
  15. Types of bond
    • Covalent
    • Ionic
    • Hydrogen
  16. Molecules
    structures consisting of atoms bound together by chemical bonds
  17. Covalent bonds
    • Two or more atoms share pair of valence electrons
    • Strongest bond
  18. Nonpolar covalent bond
    atoms share electrons equally
  19. Polar convalent bond
    • Unequal sharing of electrons
    • Enequal charge between different regions of the molecule
  20. Ionic Bonds
    • One or more valence electrons completely transferred from on atom to another
    • Form ions
    • Ionic Bond - strong electrostatic attraction between oppositely charged ions.
  21. Dissociation of ionic compounds
    • Ionic bonds weaker than covalent
    • Can dissociate in water - water atttracted electrostatically
  22. Water solubility
    • Hydrophilic - water soluble, polar molecules and ions
    • Hydrophobic - Water insuluble, nonpolar molecules
  23. Hydrogen bonds
    • weak electrostatic attraction between polar molecules
    • Responsible for: Water surface tension, water capillary actiion, Shape of proteins, DNA structure
  24. Acidity and Alkalinity
    • Some solutes (acids) release H+ when mixed with water. Increase [H+], Acidic solution
    • Some solutes (bases) bind H+ or release OH- when mixed with water. [H-], Alkaline (Basic)solution
  25. pH
    • Index of [H+] in a solution
    • Quantify acidity or alkalinity of a solution
  26. Organic molecules
    Molecules containing carrbon
  27. Macromolecules
    • Very Large Molecules
    • Clasification: 1. Carbohydrates 2. Lipids 3. Proteins 4. Nucleic Acids
    • Distinct structure and function
  28. Carbohydrates (suger)
    • Molecules that contain hydrogen, oxygend and carbon
    • Relative amounts of each are the same in basic carbohydrate subunits (monosaccharides)
    • general formula = CnH2nOn
    • Monosaccharides can have the same formula but different arrangements of atoms
    • - Isomers - molecules of same formula but different structures
  29. Disaccharides
    • two monosaccharides linked together
    • sucrose = glucoe + fructose
    • maltose = glucose + glucose
    • lactose = glucose + galactose
  30. Polysaccharides
    • Many monosaccharides linked together
    • E.g. glycogen, starch
  31. Hydrolysis Reaction
    • Carbohydrates are broken apart via hydrolysis
    • -a water molecule reacts witha a linkage between two subunits
    • -Water is consumed in the reaction
  32. Dehydration Reaction
    • Monosaccharides are linked together by dehydration
    • -Reaction occurs between hydroxil (-OH) groups located on each monosaccharide
    • -covalent bond formed between the two monosaccharides
    • -water formed as an end-product
  33. Lipids
    What are the major classes?
    • Very general category
    • Contain compounds that are not soluble in water (hydrophobic)
    • Major classes : Triglycerides, Phospholipids, Steroids
  34. Triglycerides
    What are the two types of Fatty Acids?
    • Fats and Oils
    • Structure
    • -3 Fatty Acids
    • -Glycerol-Backbone
    • Types of fatty acids : 1. Saturated 2. Unsaturated
  35. Phospholipids
    Define amiphathic
    • Contain a phosphate group (PO4) instead of third fatty acid
    • Amipathic = Posses both polar and nonpolar ends
    • -lowers surface tension of water
    • -enables hydrophobic substances to be suspended in polar solvants
  36. Sterols
    Give 3 examples
    • Basic backbone of four interlocking carbon rings
    • Different functional groups attached to basic structure
    • Examples
    • -cholesterol - precursor for other steroid hormones, regulation of cell membrane fluidity
    • -cortocosteroids - hormone produced by adrenal glands
    • -sex steroids - hormones produced by gonads (testosterone, estradiol)
  37. Proteins
    What is it structure and its function?
    • Diverse in structure and function
    • Amino acids = Building blocks
    • Basic Structure:
    • - an amino group
    • - a carboxyl group
    • - a functional side-chain (specific for the particular amino acid)
  38. Amino Acid Side Chains
    • Interactions between various side chians of amino acids
    • give protein shape
  39. Peptide Bonds
    • Peptide bond
    • -Covalent bond linking the carboxyl roup of one amino acid to the amino group of the next
    • -Dehydration reaction
    • Polypeptide - molecule consisting of many joined amino acids
  40. Level of Protein Structure
    What are the 4 levels?
    • 1. Primary Structure
    • -Sequence of amino acids in a polypeptide chian
    • 2. Secondary Structure
    • -formation of helix or sheet shpe in a protein chain
    • -Due to hydrogen bonds forming between peptide bond regions
    • 3. Tertiary Structure
    • -Twisiting and folding of a single polypeptide chian
    • -Due to chemical interactions involving the amino acid-chains
    • 4. Quaternary Structure
    • -Bonding and interactions of multiple polypeptide chains
    • -Due to chemical interactions involving the amino acid side-chains
  41. Enzymes
    • Enzymes are protein catalysts
    • Catalysts=Speed up the rate of chemical reactions
    • -Lower the activation energy for a reaction
    • Are not permanently altered in the reactions
    • Do not change the nature of the reaction
    • Enzymes catalyze reactions by binding the reactants (subtrates)
    • -orient them so that less energy is needed to get the reaction going
  42. Enzymes Catalyze Specific Reactions
    • Lock and Key Model of enzyme catalysis
    • -Active sites - bind specific substrates, catalyze specific chemical reaction, produce specific products
  43. Enzyme Function Can Change with Environmental Conditions
    Altering shape of protien will affect catalytic ability
  44. Enzymes Names
    • Many times end with ase
    • Names of enzymes typically indicate function:
    • -lactate dehydrogenase - removes hydrogen
    • -Myosin phospatase - removes phosphate groups from myosin
    • Some do not have descriptive names
    • -chmotrypsin - hydrolyzes peptide bonds
  45. DNA Structure
    • Polymer of nucleotides
    • -Nitrogen base + suger + phosphate
    • Four different bases
    • - adenine (A), guanine (G), cytosine (C), thymine (T)
    • A strand of DNA consists of many nucleotides linked through a "suger-phosphate backbone"
    • Double helix
    • -Two strands linked together by hydrogen bonds
    • -Complementary base pairing between the strands
    • -Adenine binds to thymine
    • -Guanine binds to cytosine
  46. RNA
    • Similar to DNA (polymer of nucleotides)
    • Differences
    • -Usually single-stranded
    • -Different suger (ribose)
    • Different nitorgen base (uracil instead of thymine)