Flashcards
lec day 2
Cards in this deck (29)
- 1what forms a peptide bondCondensation of amino group (NH3+) and carboxylic acid (COO-)
- 2Net charge on proteins is used inchromatographic separations
- 3The R group (side chain) of aa provides thedistinctive chemical properties of the 20 common amino acids
- 4Nonpolar side chainschains have no oxygen or nitrogen atoms that would be able to form hydrogen bonds with water or salt bridges with other charged groups.
- 5where do nonpolar side chains tend to be?These side chains have minimal water solubility (they are oily) and tend to be on the inside of proteins.
- 6Polar amino acidstypically have hydroxyl, amide, or sulfur (thiols) groups that have unpaired electrons pairs that enhance water solubility.
- 7Charged side chainsare either amines (Lys or Arg) or acids (Asp or Glu),
have charge which enable formation of salt bridges. - 89 nonpolar amino acids.amino acids have side chains (R groups) that are only C or H (no polarity) and a greasy side chains with minimal water solubility
- 9Majority of Drugs areEither Weak Acids or Weak Bases
- 10Efficacy of drugs is related totheir cellular delivery
- 11how to make peptide bond exactlypeptide ligase that catalyzes the coupling of two amino acids through the condensation of the carboxylate and amino groups with elimination of water.
- 12Primary StructureSequence of amino acids
- 13Secondary StructureRegular arrangement of amino acids near each other in linear sequence
formation of specific motifs (alpha helices or beta sheets) that involve localized interactions between proximal amino acids. - 14Tertiary StructureThree dimensional arrangement of amino acids within a linear peptide chain (protein subunit)
- 15Quaternary StructureArrangement of peptide subunits within a multi-subunit protein
- 16quinary structuretakes into account weak interactions between the protein and the surrounding cellular environment that modifies protein dynamics and structure in a manner important for stability
- 17α-Helical Secondary StructuresIntrachain hydrogen bond forms between peptide-bond carbonyl oxygen and amide (n + 4).
Forms compact and rigid conformation.
Side chains extend outward. - 18β-Sheet Secondary StructuresInterchain hydrogen bonds form between peptide segments
Exist as anti-parallel or parallel
Side chains face alternate in outward face of sheet - 19Two cysteines formdisulfide cross-link (Cystine)
- 20Disulfide cross-links stabilizeprotein fold
- 21under what conidtions can cyctein form disulfide bonds?Under oxidizing conditions (in the plasma or within the ER, Golgi)
- 22how are these disulfide bonds important?can play an important role in stabilizing proteins.
Creating these covalent bonds limits protein flexibility and unfolding, making the native fold more stable. - 23Protein Folding DiseasesAlzheimer’s Disease
Parkinson’s disease
Huntington’s Disease
Amyotrophic Lateral Sclerosis (ALS)
Retinitis pigmentosa - 24Alzheimer’s DiseaseDeposits of intracellular tau form neurofibrillary tangles; extracellular aggregates of amyloid-β form amyloid plaques.
- 25Parkinson’s diseaseFormation of protein inclusion bodies (Lewy bodies) containing α-synuclein and ubiquitin
- 26Huntington’s Disease:Expansion of polyglutamine (pQ) results in intracellular aggregation of proteins
- 27Amyotrophic Lateral Sclerosis (ALS):Formation of protein aggregates in motor neurons, associated with mutant superoxide dismutase proteins.
- 28Retinitis pigmentosa:Accumulation of misfolded mutant rhodopsin inside endoplasmic reticulum of retinal cells.
- 29—
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- Flashcards on lec day 2, created by Shylla T on 13/08/2019.
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