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47 Cards in this Set
- Front
- Back
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protein folding is driven by a number of ... interactions such as hydrogen bonding, ionic interactions, Van Der Waals' forces and hydrophobic packing.
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noncovalent
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which structure is this?
-linear sequence of amino acids held together by peptide bonds (dictated by the gene encoding that particular peptide or protein) -all other aspects of protein structure are derived directly from this structure (or sequence) or the protein! |
primary structure
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which structure is this?
-repeating structural elements produced through the hydrogen bonding of molecules in the peptide backbone itself. |
secondary structure
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what are the 2 main forms of secondary structure?
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alpha-helix and beta-sheet
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... (amino acid) is often found at the beginning of alpha helices, and ... is often found at the ends.
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proline
glycine |
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which type of secondary structure has intra-strand hydrogen bond formation?
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alpha-helix
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which structure is this?
-the folding pattern of the secondary structural elements into a 3-D conformation -designed to serve all aspects of the protein's function (binding sites, cellular localization, catalytic sites) |
tertiary structure
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protein folding is what converts a polypeptide linear chain of amino acids into a specific 3-D structure.
The process begins ..., so N-terminus begins to fold while C-terminus is still being synthesized by ribosome |
co-translationally
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protein folding results from chemical properties of individual amino acids in the ... structure of the protein
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primary
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amino acid side chain ... result in protein folding
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interactions
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... and ... groups of the peptide backbone maximize their potential to form hydrogen bonds with other backbone atims
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amide
carboxyl |
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elements of ... structure usually extend completely across compact domains
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secondary
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protein folding is aided by a class of cellular proteins known as ... or ... proteins
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chaperones
heat shock proteins |
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chaperones use energy provided by ... to assist in folding of newly synthesized protein chains.
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ATP
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2 examples of chaperone proteins are ... and ...
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Hsp70 (Bip)
Hsp60 (GroEL/GroES) |
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heat shock proteins that aid in protein folding belong to ... family
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chaperonin
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Hsp70 is located in the ... and is associated with ribosomes as the protein is forming. It stabilizes the chain until it's at the proper length to fold.
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ER
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Hsp60 is located in the ...
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mitochondria
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the protein waits to fold until it gets into the ...
This is so that we don't activate the protein early. |
mitochondria
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Heat shock proteins stop hydrophobic regions from ...
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aggregating
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The other 2 proteins involved in folding and are found in the RER are ...
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cis-trans isomerases
protein disulfide isomerases (PDI) |
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cis-trans isomerases change peptide bond configuration. Changes any ... bonds into ...
the exception would be ... (AA) |
cis
trans proline |
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protein disulfide isomerases form disulfide bonds.
ex. 2 ...(AA) form a crosslink |
cysteines
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what is this?
-abnormal accumulation (and resulting toxicity) of proteins in certain disease states -also known as protein conformational disease -caused by changes in protein folding that increase the tendency of the protein to misfold and polymerize into aggregates that are resistant to clearance and can become pathogenic |
proteopathy
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Risk factors for proteopathy:
-almost always involves in increase in ... secondary structure -destabilizing changes in primary amino acid sequence of protein (...) -abnormal ... -changes in ... and ... -increase in ... -decrease in ... -advancing ... |
-beta sheet (tend to clump more than alpha helices)
-mutations -post-translational modifications -temperature and pH -protein production -protein clearance -age |
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These are examples of what?
-alzheimer's disease, prion disease, parkinson's disease, huntingon's disease, type II diabetes, etc. |
proteopathy
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quaternary structure is present in proteins with ...
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multiple subunits
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in quaternary structure, interaction between ... may involve hydrogen binding, hydrophobic interactions, or covalent binding in the form of disulfide bonds
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individual polypeptide chains
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the 3 advantages of quaternary structure are ...
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increased stability
cooperative binding high affinity binding |
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an example of a molecule in quaternary structure that exhibits positive cooperativity is ...
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hemoglobin
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-Hemoglobin S and sickle cells are caused by a single change in amino acid sequence (...-->...) in the 6th position of the beta chains.
-leads to changes in ...(now they tend to aggregate) and ...(affinity for O2 has been lowered) |
Glu-->Val
solubility function |
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In someone with sickle cell anemia, what is it called when the hemoglobin cells clump together and the blood can't travel? It occurs during times of overexertion and stress.
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sickle cell crisis
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the sickle cell trait seems to have evolved to protect from ...
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malaria
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Immunoglobulins consist of 2 ...chains and 2 ... chains. Their quaternary structure leads to the function of binding to a specific antigen
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light
heavy |
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an example of fibrous protein is ...
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keratin
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a keratin alpha helix joins with another one to form a ..., which then combines again to form a ..., and then again to form a ...
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two-chain coiled coil
protofilament protofibril |
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keratin is high in which 2 amino acids? (they are the smallest amino acids)
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glycine and alanine
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keratin contains 14% of which amino acid? Because of this, it has a high capacity to disulfide bond.
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Cysteine
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what are the levels of keratin in the cross section of a hair? (starting with alpha helix and ending with cells)
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alpha helix, two-chain coiled coil, protofilament, protofibril, intermediate filament, cells
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to perm hair, you use a ... agent, a base like ammonium hydroxide and ammonium thioglycolate in order to break the disulfide bonds. Then you curl. And when you want to reform the new disulfide bonds, you use an ... agent, a neutralizer like hydrogen peroxide
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reducing
oxidizing |
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when a protein unfolds, or ..., it loses its 3-D shape and its function.
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denatures
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what are 5 causes of protein denaturation?
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-nonenzymatic modification (glycosylation, oxidation)
-high temperature -high concentrations of urea -extremes of pH -solvents that disrupt ionic, hydrogen, and hydrophobic bonds |
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thermal denaturation:
-enzymes and other proteins will begin denaturing at temperatures between ... -most of the time, our ... regulates our body temp so that these temps are never reached (except in cases of severe infections or dangerously high fevers) -in fried eggs, denatured albumin forms a ... - |
104 and 106 degrees F
hypothalamus white precipitate |
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We must maintain the proper temperature, otherwise proteins may begin to ... and lose their ...
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unfold
function |
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... of hemoglobin can result in protein denaturation. This can be caused by sustained high glucose levels (...)
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glycosylation
hyperglycemia |
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a glycosylated hemoglobin is also known as ...
-this serves as a valuable indicator of blood glucose levels over an extended period of time and is used to monitor how successfully a diabetic's blood sugar is being controlled. |
HbA1c
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glycosylation of hemoglobin doesn't affect ... of the protein in this case
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function
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