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UCD SF II
Science foundations II cards through 10/15
127
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Professional
10/17/2010

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Term
Function of Amino Acids
Definition
-monomers in peptides and proteins
-energy production
Term
How many groups are amino acids arranged into?
Definition
5
Term
How are amino acids classified?
Definition
by the "R" group
Term
What are the 20 amino acids coded from?
Definition
Nuclear DNA
Term
What is the source of Nitrogen in Amino Acids?
Definition
Ammonia
Term
Where do the carbon backbones of amino acids come from?
Definition
The glycolytic pathway, the pentose phosphate pathway, and the citric acid cycle
Term
What are the Non-Polar Amino Acids?
Definition
Glycine, Alanine, Valine, Leucine, Methionine, and Isoleucine
Term
What are the Aromatic amino acids?
Definition
Phenylalanine, tyrosine, and Tryptophan
Term
What are the Polar Amino Acids?
Definition
Serine, Threonine, Asparagine, Glutamine, Cystine, and Proline
Term
What are the Positively charged amino acids?
Definition
Lysine, Arginine, and histadine
Term
What are the negatively charged amino acids?
Definition
Aspartate and glutamate
Term
What is the function of carbohydrates?
Definition
energy production
structure
cellular recognition
signaling
Term
What is the cellular function of lipids?
Definition
energy production
membranes
signaling
Term
Cellular function of nucleic acids?
Definition
cellular energy
cellular messengers
biological precursors
components of DNA and RNA
Term
On what does almost all drug action act?
Definition
Proteins
Term
What is the central carbon of an amino acid called?
Definition
the alpha carbon
Term
What are the four parts of an amino acid?
Definition
alpha carbon, hydrogen group, carboxylic acid group and sidechain
Term
What is a zwitterion?
Definition
an acid having both positive and negative charges, but having a total charge of zero
Term
What can amino acids act as?
Definition
can act as an acid or a base
Term
What is the structure around the alpha carbon?
Definition
tetrahedron
Term
What is chirality?
Definition
lacking an internal plane of symmetry
Term
What are enantiomers?
Definition
two forms that are mirror images of each other that can not be superimposed upon one another
Term
Are all amino acids chiral?
Definition
No glycine is not chiral
Term
When the R group is below the alpha carbon and the amino group is on the left the amino acid is said to be ?
Definition
the Levo isomer
Term
When the R group is below the alpha carbon and the amino group is on the right the amino acid is said to be?
Definition
the Dextro isomer
Term
In pharmaceutical drugs how many forms of the drug are active?
Definition
one
Term
What what conformation are amino acids in proteins?
Definition
L-stereomers
Term
why is it important to synthesize a drug with only on chiral conformation?
Definition
to increase efficacy, and decrease toxicity
Term
How many naturally occuring amino acids are there?
Definition
20
Term
what does a small R group indicate?
Definition
more hydrophilic, and more water soluble
Term
What is the most soluble amino acid?
Definition
Glycine
Term
What is the only cyclic amino acid?
Definition
proline
Term
Polar amino acids are more soluble because they ____?
Definition
can form hydrogen bonds with water
Term
Which amino acid forms disulfide bonds?
Definition
Cysteine
Term
How many polypeptide chains and disulfide bonds does insulin contain?
Definition
2 polypeptide chains and 3 disulfide bonds
Term
why do negatively charged amino acids form salt bridges?
Definition
to neutralize the charge
Term
Aromatic are groups are _________ and cluster in the protein interior.
Definition
hydrophobic
Term
True or False.
Proteins are functional over a large pH range.
Definition
False
Term
Amino acids in low pH, the COO- ?
Definition
accepts a proton from water
Term
An amino acid at high pH, the NH3+ ?
Definition
donates a proton to water
Term
What is the isoelectric point?
Definition
the point when the pH of the solution is neutral
Term
how do you calculate the isoelectric point?
Definition
take the average of the preceeding and proceeding pKa values to the neutral form. (eg -1, 0, +1)
Term
What are the titratable parts of an amino acid?
Definition
carboxylic acid group (COO-), amino group (NH3+) and the side chain
Term
What are the least frequently appearing amino acids?
Definition
Tryptophan and Cysteine
Term
What are the most frequently appearing amino acids?
Definition
leucine and alanine
Term
What hormone is produced by the pineal gland and regulates the sleep wake cycle?
Definition
Melatonin
Term
From what amino acid is melatonin derived?
Definition
tryptophan
Term
Major depression, obsessive compulsive disorder, and other anxiety disorders are associated with?
Definition
low serotonin levels
Term
What is the intermediate between tryptophan and melatonin?
Definition
serotonin
Term
What is dystonia?
Definition
A movement disorder that causes involuntary muscle contractions and spasms
Term
High levels of serotonin are associated with what disease states?
Definition
psychosis and schizophrenia
Term
What is epinephrine used to treat?
Definition
Cardiac Arrest
Term
What reaction forms a peptide bond?
Definition
A condensation or dehydration reaction
Term
True or False.
Peptides contain only one free alpha amino group and one free alpha carboxyl group.
Definition
True
Term
What is PKU?
Definition
phenylketonuia-inability to metabolize phenylalanine
Term
What does conjugating glutathione to drugs do?
Definition
makes them more water soluble
Term
Can a protein contain more then one polypeptide chain?
Definition
yes
Term
are prostetic groups made up of amino acids?
Definition
no
Term
in what conformation are 99% of peptide bonds?
Definition
Trans conformation
Term
What two process drive protein folding?
Definition
burying the hydrophobics and satisfying polar and charged groups
Term
reactions always proceed in the direction of ?
Definition
Disorder
Term
hydrogen bonds and electrostatic interactions contribute to protein structure by?
Definition
reducing energy cost of unpaired polar/charged groups
Term
hydrophobic interactions contribute to protein structure by ?
Definition
increasing disorder of solvent
Term
how many amino acid residues are required to make one helix turn?
Definition
five
Term
Hydrogen bonds are ______ to the helix backbone?
Definition
parallel
Term
a repeating unit contains how many residues?
Definition
3.6
Term
natural proteins are what kind of amino acids?
Definition
L-amino acids
Term
What are the destabilizing interactions in an alpha helix?
Definition
Large R groups too close, and electrostatic repulsion
Term
what are stabilizing interactions in alpha helices
Definition
electrostatic attraction
Term
how many residues from the end until hydrogen bonding can occur?
Definition
4 residues from each end
Term
Helices prefer ____ charged amino acids on the N terminus and _____ charged amino acids on the C terminus end.
Definition
Negatively, Positively
Term
two processes in protein folding?
Definition
nucleation and propogation
Term
What is the first step in protein folding?
Definition
Nucleation
Term
Why would glycine disfavor alpha helices?
Definition
High conformational flexibility when free
Term
Which amino acid most favors the alpha helix?
Definition
Alanine
Term
Which amino acid causes kinks in the helix?
Definition
Proline
Term
Proline is know as a helix breaker and is one of the ______ that prevents propagation.
Definition
Helix caps
Term
What are beta strands?
Definition
hydrogen bonds between adjacent segments of polypeptide chains
Term
Describe parallel beta sheets.
Definition
Main chain atoms are aligned, and nonlinear N-O/O-H bonds
Term
Right handed connections between beta sheets produce _________ angles.
Definition
Shorter
Term
Describe antiparallel beta sheets.
Definition
N-O/O-H bonds aligned, and main chain atoms are not aligned
Term
What are beta turns?
Definition
180 degree turns involving four amino acids
Term
how do beta hairpins fold?
Definition
by beta turn or sidechain stabilization interactions
Term
Which form of proline is always found in beta turns, cis or trans?
Definition
Cis form
Term
What are the two main classifications of proteins?
Definition
fibrous and globular
Term
what do fibrous proteins contribute to the structures they appear in?
Definition
strength and flexibility
Term
Why are fibrous proteins insoluble in water?
Definition
They contain large amounts of hydrophobic residues
Term
Hair waving and curling is the result of ?
Definition
disulfide bond breakage
Term
What type of helix is collogen?
Definition
Left handed alpha helix
Term
How many amino acid residues are required to make one turn in collogen?
Definition
three
Term
The amino acid sequence of collogen is generally?
Definition
A repeating tripeptide unit
Term
True or False.
Mutating glycine in collagen can result in lethal diseases.
Definition
True
Term
the interior of globular proteins resemble?
Definition
crystal
Term
define motif
Definition
folding pattern involved in two or more secondary structural elements and the connections between them
Term
What is a domain of a protein?
Definition
part of a polypeptide that is stable or could undergo movement as a single entity with respect to the whole protein
Term
do different domains in a protein have different functions?
Definition
yes
Term
What is the quaternary structure of a protein?
Definition
the 3D arrangement of more then one polypeptide chain
Term
What interactions stabilize protein structure?
Definition
disulfide bonds, hydrogen bonds, hydrophobic interactions, electrostatics, ion pairs, and van der Waals interactions
Term
What are the two steps involved in peptide synthesis?
Definition
transcription and translation
Term
What are the three pathways of a protein?
Definition
folding, aggregation, and recycling by proteases
Term
What contains the information for the 3D folding of a polypeptide
Definition
Amino acid sequence
Term
are peptide bonds hydrophillic or hydrophobic?
Definition
hydrophillic
Term
What are chaperonins?
Definition
proteins that facilitate the proper folding of large polypeptides
Term
How do chaperonins function?
Definition
by bonding to hydrophobic residues preventing inappropriate aggregation
Term
Do chaperonins actively promote folding?
Definition
No
Term
What are two enzymes that promote folding?
Definition
Protein disulfide isomerase, and peptide prolyl isomerase
Term
What is required for proper protein function?
Definition
proper folding of the protein
Term
What is the single largest parameter that triggers disease?
Definition
decrease in protein stability
Term
Decreased protein stability results in?
Definition
excessive protein aggregation
Term
True or False.
Proteins are stable over very narrow experimental perameters.
Definition
true
Term
true or false
proteins can be denatured by increasing or decreasing the temperature.
Definition
true
Term
What are the two types of protein aggregates?
Definition
amyloid and nonamyloid
Term
are all types of protein aggregates toxic?
Definition
yes
Term
what is the lag phase in amyloid formation?
Definition
nucleation of initial amyloid structure
Term
what is propagation in amyloid formation
Definition
docking of molecules to the preformed nuclei
Term
What can speed up aggregation?
Definition
Agitation and agents that destabilize proteins
Term
What is the life span of an RBC in a patient with sickle cell anemia?
Definition
10-20 days
Term
how many mutations in hemaglobin cause sickle cell anemia
Definition
one
Term
The result of a mutation on glu-6 results in a hydrophobic/hydrophillic residue?
Definition
hydrophobic
Term
true or false.
sickle cell molecules aggregate forming twinned helical bundles
Definition
True
Term
what factors can denature therapeutic proteins?
Definition
pH, denaturants, contaminants, pressure, and freezing/thawing
Term
shaking of protein formulations can cause protein aggregation
Definition
True
Term
silicone oil induces protein aggregation
Definition
true
Term
protein aggregates are formed from ?
Definition
partially unfolded species
Term
first hypothesis in inhibition of aggregates
Definition
increase stability of native state, while maintaining function and safety
Term
Second hypothesis in inhibition of aggregates.
Definition
shift equilibrium toward native state
Term
If a ligand binding two states is different, then equilibrium will be shifted to favor state with greater binding
Definition
true
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