Friday, January 21, 2011

start of physiology

                Study of the changes of normal mechanical, physical, and biochemical functions, either caused by a disease, or resulting from an abnormal syndrome
                Physiology is the study of normal, healthy bodily function
Comparative Physiology
                Studies and exploits the diversity of functional characteristics of various kinds of organisms

                All chemical changes in the body, happens in the cell
                Synthesis process
                Forming molecules using energy
                Splits molecules releasing energy

                Balance of optimum amounts of gases, nutrients, ions, temp, & pressure in the ECF
                                ECF = extra cellular fluid
                                                Outside the cell
                                                Intercellular fluids & plasma
                Dynamic balance
                                 Changes in the amounts is constantly changing to be kept within an acceptable range
                Imbalance of homeostasis leads to disease and/or death

                Stimulus that causes an imbalance in homeostasis
                Most are mild & routine which the body is used to handling

2 control groups for homeostasis
                Nervous system
                Endocrine system
                Both make changes in rates at which things change

                Nervous system
                                Rapid response
                                Using both sensory and motor neurons
                Endocrine system
                                Slow response
                                Lasts longer

                Feedback system
                                Circular system
                                Status is continually fed back to control region which send out info to maintain or                                             change current trends in homeostasis
                                Negative feedback
                                                More common than positive feedback
                                                Is a reversal
                                                                blood sugar is too high
                                                                Insulin is released to bring blood sugar down to normal range
                                Positive feedback
                                                Increases or maintains the current amount in the body

Organic Chemistry
                4 groups of organic compounds in the body
                Long chain compounds
1.       Carbs
2.       Lipids
3.       Proteins
4.       Nucleic Acids

                Starches & sugars
                Will end with –ose
                Monosaccharide (simple sugars)
                                Easily broken down
                                Easy release of energy
                                Storage form of carbs
                                 Branched Polysaccharide
                                Linear polysaccharide of several glucose molecules
                                Plants storage form of carbs
                                Plant cell walls
                                Polymer of glucose
                                Humans can’t break it down due to lack of an enzyme

                Dehydration synthesis
                                Chemical reaction that involves the loss of water from the reacting molecule
                                Glucose + Glucose à Maltose + water   
                                Maltose is a disaccharide

                                chemical process in which a certain molecule is split into two parts by the addition of a                                   molecule of water
                                Maltose + water = Glucose + Glucose
                Dehydration synthesis & Hydrolysis are both usually completely reversible with one another
                Extra example
                Lactose + water à Glucose + Galactose
                Glucose + Galactose à Lactose + water
C6H12O6 + 602 + 2H2O à 6CO2 + 12H20 + Energy

                Less oxygen in the molecule than carbs
                Richest source of energy in the body
                Harder to break down and release the energy
                Packs, fills and shapes the body
                                Glycerol + 3 fatty acids
                                Long chain
                                Saturated = full of single bonded Hydrogen
                                                Dehydration synthesis yields 3 waters
                Subgroup of the steroids and an important class of organic molecules
                The most familiar type of animal sterol being cholesterol
                Cholesterol is vital to cellular function, and a precursor to fat-soluble vitamins and steroid            hormones

                Membrane associated lipids
                Local/tissue hormone
                Work in the area produced
                Most often associated with pain stressors

                Made of Carbon, Hydrogen, Oxygen, and Nitrogen – sometimes sulfur and phosphorus
                Amino acid base
                                NH2 = Amino
                                COH = Acid
                R group is the functional group that changes
                Generally a polymer
                Uses dehydration synthesis
                Forms 3 peptide bonds and 3 waters
                Di peptide
                4 levels of structure
1.       Linear arrangement
                The amino acid sequence
2.       Special orientation
                                                H-O weak polar bonds here
                                                pH or temp can break the bonds
3.       Overall structure
4.       Several proteins
                More than 1 polypeptide chain

                                Catalyst speeds up rate of reaction without changing
                                A catalyst is not consumed by the reaction itself
                                Given the ending of –ase

Nucleic Acids
                DNA deoxyribonucleic acid
                RNA ribonucleic acid
                                5 carbon sugar
                                Ribose = RNA
                                Deoxyribose = DNA
                Has a phosphate group
                And base group
                                Thymine à DNA only
                                Uracil à RNA only
                DNA codes for protein synthesis
                DNA & RNA
                                Base unit is a nucleotide
                                Nitrogen base
                                Characteristics reflected by DNA & RNA
                                                All your DNA
                                                Unit of heredity
                                                Denoted by regions
                                                Genetic makeup
                                                What you can actually see
                                Storage form of energy
                                5 carbon sugar
                                Adenosine + 3 phosphate groups
                                High energy bonds
                                                6x energy for the first phosphate group released (diphosphate now)
                                                4x for 2nd
DNA replication
                Occurs during interphase
                Forms a replication fork λ shaped
                                Where DNA is synthesized
                                Each strand acts as a template
                                Semi conservative replication
                                Enzymatic process
                                                DNA polymerase adds bases
                                Primer starts
                                                Short RNA molecule
                                                Complimentary to strand

                Single strand & helical
                Bases dictated by DNA, making it complimentary to a DNA strand
                Thymine is replaced by Uracil
                Involved in protein synthesis
                3 types formed same way
                                Each type serves a different function
                Messenger RNA (mRNA)
                Transfer RNA (tRNA)
                Ribosomal RNA (rRNA)
                RNA polymerase
                                Adds bases to RNA
                                DNA à RNA
                                Enzymatic process
                                DNA to complimentary RNA strand
                                The process of creating a complementary RNA copy of a sequence of DNA
                                Starts at a Promoter site
                                Ends at a terminator site
                                Produces mRNA
                                mRNA to protein production
                                Occurs in the cytosol with ribosomes
                                The ribosome facilitates decoding by inducing the binding of tRNAs with complementary                                              anticodon sequences to that of the mRNA
                                tRNA activates with ATP

                                triplet of bases on mRNA
                                used to translate into particular proteins
                                nonsense codons are used as stop sites
                                Triplet of bases on tRNA
                                Complimentary to mRNA
                Nonsense codon
                                Stop site
                                Small unit
                                                Binding site for RNA
                                Large unite
                                2 parts
                                                The A site binds an amino acid
                                                The P site binds a peptide
                Permanent change in genetic code (DNA)
                Can happen over time or suddenly
                Can be good or bad
                Point mutation
                                Single DNA base changed
                                3 types
                                                Swaps a base for another
                                                Adds in a base & causes a frame shift outward
                                                Subtracts a base & causes a frame shift inwards
                                Chromosome crossing over with a different homologous pair

                Glucose Oxidation
C6H12O6 + 602 + 2H2O à 6CO2 + 12H20 + Energy

Energy of activation
                the energy that must be overcome in order for a chemical reaction to occur
                Can lower the energy that must be overcome
                Speeds up rate of reaction
                Does not alter temperature pressure or pH
                Can be very specific or general
                In the animal Enzymes are protein catalysts

                                Have ideal operating zones regarding temperature pH and pressures
                                Maximum rate is also when saturated with substrates

                Apo Enzymes
                                Must combine with a cofactor or substrate
                                                Organic compound for animals
                                                Cofactors include NADH, NADPH and adenosine triphosphate (ATP)

                                Active site
                                                Where enzyme reacts with substrates
                                                Lock and key method of reacting
                                                Reactants must fit the enzyme to have the process completed

                Metabolic pathways
                                Several catalizations to get to the final product
                                                Removes oxygen, hydrogen and/or electrons
                                                Can be called cellular respiration
                                                Occurs in every cell
                                                Is what releases ATP
                                                Adds oxygen, hydrogen and/or electrons
                                Paired/coupled reactions
                                Cellular respiration is the oxidation of glucose (C6H12O6) to CO2 and the                                                                  reduction of oxygen to water. The summary equation for cell respiration is
                                                                                C6H12O6 + 6 O2 → 6 CO2 + 6 H2O

                                A release of energy
                                Used the energy released by catabolism
                Glucose à glycogen = Glycogenesis
                Glycogen à Glucose = Glycolysis
                acetyl-CoA à Fats = Lipogenesis
                triglycerides à free fatty acids = Lipolysis
                non carb à glucose = Gluconeogenesis

3 pathways  for glucose oxidation
                Krebs cycle
                Electron transport series (ETS)

                                Occurs in the cytoplasm
                                Starts with glucose C6H12O6
                                10 reactions
                                                Each catalyzed by a different enzyme
                                2 ATP required for energy of activation
                                                2 pyruvic acids
                                                4 ATP
                                                2 NADH
                Transitioning to Krebs Cycles
                                Takes those 2 pyruvic acids formed from glycolysis
                                Moves then into the mitochondria
                                Forms Acetyl Coenzyme A
                                                In the process it losses a Carbon to form CO2 waste byproduct
                                                2 NADH

                Krebs Cycle
                                                6 NADH
                                                4 CO
                                                2 FADH
                                                2 ATP
                Electron Transfer Series
                                                30 ATP à from NADH; each NADH yield 3 ATP in ETS
                                                4 ATP   à from FADH; each FADH yields 2 ATP in ETS

                Totaling 38 ATP gain from 1 glucose molecule
                (34 from ETS & 4 from glycolysis)

                Process of making glycogen
                500g is usual storage
                Stored in skeletal and cardiac muscle
                Insulin triggers the storing

                Stored as fatty acid from sugar
                Starts from insulin
                Creates largest reserve of energy in the body
                                Fat yields 9kCal/gram
                                Carbs yield 4kCal/gram
                Lipase splits fatty acids off of glycerol

(Beta Oxidation)
                Splits long chain fatty acids into 2 Carbon pairs
                Occurs in the mitochondria
                to generate Acetyl-CoA, the entry molecule for the Krebs cycle.
Nervous system

Na+ +   Na+
K+    -      K+
Na+ +   Na+

The Na+/K+  pump helps maintain the neurons resting potential
Resting potential is ~ 70 millivolts (mv)

An action potential = axon stimulus
                Allows Na into the cell causing depolarization
                After the impulse passes K moves out of the cell to repolarize
                                Short refractory period after repolarization when the cell cannot allow another impulse
                                Na is moving back out and K is moving back in
Synaptic End bulb
                Ca++ moves into the bulb to help pull synaptic vesicles to the presynaptic cleft
                ACh is the neurotransmitter
                AChE removes ACh
                The action can be to stimulate or to inhibit

Liminal stimulus
                A stimulus sufficient enough to cause a contraction
                A Stimulus not sufficient enough to cause a contraction

Neurons obey the All-or-None law
                Meaning a stimulus above the threshold will give the maximum reaction
                And a stimulus below the threshold will get nothing
Medulla oblongata
                Mostly white matter
                Reticular formation
                                White and grey matter mixed together
                Nuclei for vital centers