What are some processes that biomolecules are necessary for?
Breaking down food molecules
generating energy
storing energy (lipids)
What are proteins?
A series of amino acids, or polymers
What are components make up an amino acid?
Amine group and carboxylic acid group.
What is the composition of a carbohydrate?
either ketones or aldehyde with a hydroxide.
What type of substances are lipids soluble?
Non polar organic substances
Classify the functional groups that would commonly be seen with a lipid.
Non-polar
What is the general structural "backbone" of nucleic acids made up of?
Sugars
What is the backbone of DNA?
Deoxyribose
What is the backbone of RNA?
Ribose
Define proteins
large biological molecules of multiple amino acids linked via amide (peptide) bonds
What type of proteins speed up reactions?
Enzymes
What is the function of urease? two enzymes were mentioned during the lecture and what are their functions?
Urease: Catalyzes the hydrolysis of urea into Co2 and ammonia
Acetylcolinesterase:breaks down acetylcholine
What is an example of a storage protein?
Myoglobin
Give an example of a transport protein.
hemoglobin
What is an example of a structural protein?
Collagen
Name a type of protein that confers protection to our bodies?
Immunoglobulin
What are some examples of motion proteins?
actin and myosin
What allows proteins to have such a variety of functions?
They are linier polymers linked together
they have 3d strucures
they contain a variety functional groups
can also connect with other biochemical molecules
What determines the function of proteins?
3d structure
What are the four parts of an amino acid?
central carbon
basic amino group
acidic carboxyl group
side chain
In an amino acid, where is the alpha carbon?
Adjacent to the carboxyl group.
What determines the difference in amino acids?
Various side chains
How many total amino acids are there? How many are used to build proteins?
300 and 20 respectively
What determines 3d structure and charge on a protein?
Various R groups
True or false: A proteins often carry a charge.
True
What are two reasons proteins may not be able to cross the lipid bilayer?
they are charged particles and they are quite large.
All amino acids contain at least one asymmetrical carbon with the exception of what?
glycine
Jeopardy:
The L- configuration
What configuration do all naturally occurring proteins take?
Why are amino acids naturally occurring in proteins only of the L-configuration?
The enzymes that synthesize the proteins only insert the L amino acids in the chain.
What is the primary structure of a protein?
The specific amino acid sequence of the protein.
By what process are proteins synthesized?
Polymerization
What is another name for a peptide bond?
amide
If polymer means plural then _______ means singular.
Monomer
What molecule is liberated during the formation of a peptide bond?
H2O
Individual amino acids can be called what other name?
amino acid residues
When was the amino acid sequence of insulin discovered?
1950
Why was the sequencing of insulin an important discovery in biochemistry.
It showed that a protein has a unique sequence of amino acids and they also discovered that the sequence of amino acids has a genetic basis.
What makes up the regular and repeating patterns associated with secondary structure?
hydrogen bonds that occur between backbone atoms of hydrogen and oxygen in neighboring segments of the chain.
Bonds that create the secondary structure in a protein occur between what atoms?
oxygen and hydrogen
Which structure gives a protein its overall 3d shape?
The tertiary structure.
Folding of the polypeptide chain by tertiary structure occurs by what mechanism?
bonding between R to R
What does quaternary structure refer to?
The way in which larger proteins come together to form larger aggregates.
what is an important example of quaternary structure?
hemoglobin.
What reactions are associated with proteins?
Hydrolysis
denaturation
What is hydrolysis?
The breaking of peptide bonds via the introduction of water.
What is the reverse of polymerization?
Hydrolysis
How are proteins digested?
Hydrolysis
When the primary structure of protein is not changed but any of the other secondary, tertiary or quaternary structures is changed, this is termed?
denatured
Can denatured proteins re-nature? he he
The process is usually not reversible.
What causes denaturing to occur?
Heat
Mechanical aggitation
Extremes of pH
How many polypeptide chains are in hemoglobin, and what are their designations?
4 total, 2 alpha-er and 2 beta-er (he he)
What holds together the polypeptide chains of hemoglobin?
various groups, specifically 4 heme units
What does a heme unit consist of?
Organic component containing a central iron atom
How many units of O2 can a hemoglobin protein carry?
4 (molecules/atoms)
What substances causes blood to have its red color?
Heme units
What occurs to give sickle cells their distinct shape?
Substitution of an amino acid.
In hemoglobin A, what amino acid substitution will mutate it into hemoglobin S?
valine is substituted for Glutamine to form the S variant.
Is it the alpha or beta chains that is effected in sickle cell anemia?
the beta chains
How is can we determine the type of hemoglobin that a patient carry's?
Electrophoresis
Under what conditions is sickle cell trait inherited?
Receiving hemoglobin A from one parent and hemoglobin S from the other.
What is phenlkenonturia?
Absence or deficiency of phenylalanine hydroxylase thereby leading to an accumulation of phenylalanine.
What is phenylalanine normally converted to?
Tyrosine
How is phenylketonuria passed on?
autosomal recessive transmission
What is the treatment for phenylalanine?
Low phenylalanine diet soon after birth
What causes albinism?
Lack of enzyme tyrosinase
Lack of melanocytes and melanin
In what fashion is albinism passed down?
autosomal recessive
What is a prion?
A brain protein that converted to a proteinaceaous infectious particle.
What specific change in protein structure makes prions infective?
Changed in the secondary structure.
How many of the "basic set of amino acids" can humans produce?
11
What do we call the 9 amino acids that humans can't produce and where do we get them?
essential amino acids and we have to get them through our diet.
From what amino acid precursor does histamine come?
histidine
From what amino acid precursor do thyroxine epinephrine, and melanin come from?
tyrosine
Why do epinephrine and thyroxine have similar side effects?
because they both originate from tyrosine
What is the problem with porphyria?
there is a disruption in the pathway of heme sythesis
What causes an accumulation of intermediates in the porphyrin pathway?
Anything that induces an increase in heme requirements.
What is the precursor to porphyrins?
Glycine and succinly CoA (acetic acid/acetate)
What determines the type of porohyria that is manifested?
The specific enzyme deficiency in the chain
What is the most serious form of porphyria?
Acute intermittent porphyria
How is acute intermittent porpyria passed on?
autosomal dominant
What is the goal of anesthesia when treating a pt with porphyria?
Not provoke an attack
When an attack of porphyria occurs how is it manifested and what is the pain often confused with?
Sever abd pain and deficiencies in the CNS and PNS. Often mistaken as cholecystitis, pancreatitis, appendicitis, renal cholic.
What happens to the nerves when a porphyria attack occurs?
Demyelination that results in:
-motor weakness
-diminished reflexes
-autonomic nervous dysfunction
-neuropathy
-impaired function of the cranial nerves
What can occur intraoperatively with a porphyria pt?
labile hemodynamics
diaphoresis
arterial vasospasm
respiratory muscle paralysis
What medications would we avoid with a pt who has porophyria?
barbituates
benzodiazepines
ketamine
etomidate
What medications are "safe" with a porphyria pt?
narcotics
volitiles
muscle relaxants
How does induction of the CYP450 enzyme precipitate in an attack of a porphyrin?
Enzyme induction to CYP450 causes an increase in the requirements of the porphyirin pathway.
T or F: Enzymes are mostly lipid soluble proteins.
false
How does an enzyme make a process more efficient?
Decreases the energy of activation
What is an enzymes function?
to catalyze a reaction
Fill in the blank. Enzymes are usually _____ and more _______ than inorganic catalysts.
Bigger, complex
In the absense of an enzyme are biological reactions fast or slow in general?
Most biological reactions aren't perceptible without an enzyme to speed things up
Do enzymes effect a wide variety of tissues?
No, they are highly specific.
What are three examples of enzymes brought up in class?
carbonic anhydrase
acetylcholinesterase or true cholinesterase
plasma cholinesterase or pseudocholinesterase
What reaction does carbonic anhydrase catalyze?
the hydration of CO2 and H2O into H2CO3 and the reverse reaction
Carbonic anhydrase is the fastest known enzyme, How fast is it?
It hydrates 1 million molecules a second and speeds up the reaction by 10 million times.
What is the role of Acetocholinesterase?
Splits acetylcholine into choline and an acetate ion
Where is the site of acetylcholine release?
cholinergic neurons
neuromuscular junction
What happens to the choline that has been split from acetylcholine?
It is transported back into the cell for recycling.
What substance does pseudocholinesterase break down?
succinylcholine
Where is pseudocholinesterase produced and where is it present?
in the liver, in the blood plasma
What happens to most of the dose of succ we give before it reaches the neuromuscular junction?
It is broken down in the plasma by pseudocholinesterase
How does Pseudocholinesterase breakdown the succ that reaches the neuromuscular junction?
the succ will need diffuse back out of the junction to be broken down
Which has a longer mechanism of action succinylcholine or acetylcholine and why?
succ, because succ has to diffuse back out of the nm-junction prior to being broken down, and is essentially di-acetylcholine.
What is the structure of succinylcholine?
two acetylcholine molecules bound together. This binding makes the duration of action last longer.
How is pseudocholinesterase deficiency passed down?
"It's an inherited disorder."
What does pseudocholinesterase deficiency or absence effect?
Prolongs the response to succ
Aside from the inherited form of pseudocholinesterase deficiency, who else has a decrease of this enzyme?
pt's with liver disease
pregnant pt's
What is the relationship between substrate and enzyme concentrations?
If there is a smaller number of substrate to enzyme then only some of the enzymes will be working. We can add additional substrate and increase the amount of reaction occurring until the numbers of substrate exceed that of the enzyme and then the reaction rate will reach a point where adding more substrate will not speed up the reaction.
Is the reaction rate proportional or inverse to the number of enzymes available to react with substrate?
Proportional
Aside from concentration of substrate and enzyme, what other factors can effect the reaction rates?
temperature and pH
What is the ideal pH range in which enzymes work?
5 - 9
What two systems are responsible for regulating the chemistry of our bodies?
the autonomic nervous system and the endocrine system, Neuro-endocrine control
What are the chemical messengers of the endocrine system?
Hormones
What is the pathway of a hormone?
secreting organ→blood→interstitial fluid surrounding organ→target organ
Which of the nervous or endocrine system is faster?
nervous
How does the nervous system send its signals?
mainly electrical signals but also neurotransmitters
What are the two classifications of hormones?
Protein derivatives or lipid derivatives
What are the sub classes of protein derivatives?
amino acid derivatives
polypeptides
What two general roles does epinephrine play in the body?
hormone and neurotransmitter
What are the largest class of hormones?
polypeptides
How many amino acids is TSH?
108
How many amino acids is insulin?
51
The lipid derivative hormones belong to which subclass?
steroids
Where are the control centers of the autonomic nervous system?
hypothalmus
the brainstem
spinal chord
Why is it important to understand the autonomic NS?
because many of the drugs that we use are stimulating or blocking portions of the ANS.
What are the two divisions of the ANS neurons?
presynaptic (preganglionic) and postsynaptic (postganglionic)
How do the pre and post synaptic neurons communicate?
the release and binding of neurotransmitters in the synaptic cleft
How do the postsynaptic neuron a target tissues communicate?
the release and binding of neurotransmitters in the neuromuscular junction
To what what group do most of the neurotransmitters belong?
amines
What is the neurotransmitter of the presynaptic neurons?
acetylcholine
If a receptor is acted on by acetylcholine it a(n) ________ receptor?
cholinergic
In the parasympathetic NS, what is the neurotransmitter of the post synaptic neuron?
acetylcholine
In the sympathetic NS, what is the neurotransmitter of the post synaptic neuron?
Norepinephrine
If norepinephrine acts on a receptor it is a(n) __________ receptor?
adrenergic
What type of receptors do the β blockers and β agonist's bind to?
Adrenergic
What are the two types of cholinergic receptors?
Nicotinic
muscarinic
Do the nicotinic and muscarinic receptors respond to the same neurotransmitter?
Yes: acetylcholine but will act differently according to the receptor bound
Where are the nicotinic receptors found?
at the synapse between pre and post synaptic neurons in both the SNS and the PSNS; and at the neuromuscular junction of the SNS
Where are the the muscarinic receptors found?
in the end organs of the PSNS.
In the ___ the preganglionic fiber is shorter than the postganglionic fiber.
SNS it is the opposite in the PSNS
What is the agonist to the muscarinic receptors?
acetylcholine
muscarine
What are the antagonists of the muscarinic receptors?
Antimuscarinics:
-Atropine
-scopolomine
-glycopyrolate
What are the agonists of the nicotinic receptors?
acetylcholine
Nicotine
What are the antagonists of nicotinic receptors?
nondepolarizing muscle relaxants
ganglionic blockers:
-⇂bp
Where do the ganglionic blockers block the action of acetylcholine?
at the ganglia or neural synapse
What is the goal of anesthesia in muscle relaxant reversal?
maximize nicotinic transmission in the neuromuscular junction but to also give an antimuscarinic to block the effects of acetylcholine at the end organ.
Acetylcholine binding to the muscarinic receptors in the heart would have what effect on the heart rate?
decrease
How does the drug Aricept work?
it increases acetylcholine in the the brain
What is the role of acetyl-SCoA in the the formation of acetylcholine?
Acetyl-SCoA binds its Acetyl to choline to form acetylcholine
What end organs have muscarinic receptors? (according to the slide 31)