Wednesday, August 17, 2011
Friday, January 21, 2011
start of physiology
Pathophysiology
Study of the changes of normal mechanical, physical, and biochemical functions, either caused by a disease, or resulting from an abnormal syndrome
Physiology
Physiology is the study of normal, healthy bodily function
Comparative Physiology
Studies and exploits the diversity of functional characteristics of various kinds of organisms
Metabolism
All chemical changes in the body, happens in the cell
Anabolism
Synthesis process
Forming molecules using energy
Catabolism
Breakdown
Splits molecules releasing energy
Homeostasis
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
Stress
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
Example
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
Carbs
C6H12O6
Starches & sugars
Will end with –ose
Monosaccharide (simple sugars)
Glucose
Fructose
Galactose
Sucrose
Easily broken down
Easy release of energy
Glycogen
Storage form of carbs
Branched Polysaccharide
Starch
Linear polysaccharide of several glucose molecules
Plants storage form of carbs
Cellulose
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
Example
Glucose + Glucose à Maltose + water
Maltose is a disaccharide
Hydrolysis
chemical process in which a certain molecule is split into two parts by the addition of a molecule of water
Example
Maltose + water = Glucose + Glucose
Dehydration synthesis & Hydrolysis are both usually completely reversible with one another
Extra example
Hydrolysis
Lactose + water à Glucose + Galactose
Dehydration
Glucose + Galactose à Lactose + water
C6H12O6 + 602 + 2H2O à 6CO2 + 12H20 + Energy
Lipids
Insoluble
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
Triglycerides
Glycerol + 3 fatty acids
Long chain
Saturated = full of single bonded Hydrogen
Dehydration synthesis yields 3 waters
Sterols
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
Prostaglandin
Membrane associated lipids
Local/tissue hormone
Work in the area produced
Most often associated with pain stressors
Proteins
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
Enzymes
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
Nucleotide
5 carbon sugar
Ribose = RNA
Deoxyribose = DNA
Has a phosphate group
And base group
Guanine
Cytosine
Thymine à DNA only
Adenine
Uracil à RNA only
DNA codes for protein synthesis
DNA & RNA
Base unit is a nucleotide
Nitrogen base
Characteristics reflected by DNA & RNA
Genome
All your DNA
Gene
Unit of heredity
Denoted by regions
Genotype
Genetic makeup
Phenotype
What you can actually see
ATP
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
RNA
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
Transcription
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
Translation
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
codon
triplet of bases on mRNA
used to translate into particular proteins
nonsense codons are used as stop sites
Anticodon
Triplet of bases on tRNA
Complimentary to mRNA
Nonsense codon
Stop site
Ribosomes
Small unit
Binding site for RNA
Large unite
2 parts
The A site binds an amino acid
The P site binds a peptide
Mutation
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
Substitution
Swaps a base for another
Addition
Adds in a base & causes a frame shift outward
Subtraction
Subtracts a base & causes a frame shift inwards
Recombination
Chromosome crossing over with a different homologous pair
Metabolism
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
Catalyst
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
Enzymes
Have ideal operating zones regarding temperature pH and pressures
Maximum rate is also when saturated with substrates
Apo Enzymes
Dormant
Must combine with a cofactor or substrate
Cofactor
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
Oxidation
Removes oxygen, hydrogen and/or electrons
Can be called cellular respiration
Occurs in every cell
Is what releases ATP
Reduction
Adds oxygen, hydrogen and/or electrons
Paired/coupled reactions
Example:
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
Catabolism
A release of energy
Anabolism
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
Glycolysis
Krebs cycle
Electron transport series (ETS)
Glycolysis
Anaerobic
Occurs in the cytoplasm
Starts with glucose C6H12O6
10 reactions
Each catalyzed by a different enzyme
2 ATP required for energy of activation
Yields
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
Yields
2 NADH
Krebs Cycle
Yields
6 NADH
4 CO2
2 FADH
2 ATP
Electron Transfer Series
Yields
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)
Glycogenesis
Process of making glycogen
500g is usual storage
Stored in skeletal and cardiac muscle
Insulin triggers the storing
Lipogenesis
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
Lipolysis
(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
http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter14/animation__the_nerve_impulse.html
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
Subliminal
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
Respiratory
Cardiac
vasomotor
Subscribe to:
Posts (Atom)