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Sem título
Flashcards do conjunto (22)
- 1What is the primary structure in proteins formed from?a sequence of amino acids joined by peptide bonds
- 2What is a secondary structure in proteins formed from?a-helix and B-pleated sheets, coiled and folded
Peptide and hydrogen bonds - 3What is the tertiary structure of a protein formed from?interactions between side chains
peptide, hydrogen bonds, disulfide bridges, hydrophobic and Van Der Waals - 4What is a quaternary structure in a protein formed from?2 or more polypeptide chains form 1 macromolecule
all the same bonds as tertiary - 5What is the difference between Anfinsen's experiment and Levinthal's Paradox?Anfinsen= sequence of aa determines a proteins 3D structure
Levinthals= proteins must fold in 'pre-arranged pathways' and in a cooperative manner - 6What is protein folding?is a multidimensional energy landscape and can take place with the help of chaperones
- 7What are chaperones, and the 2 major classes of them?... unfold misfolded proteins before degradation by proteasome unit and protect proteins from interfering interactions during folding
Molecular chaperones (act as monomers)
Chaparonins (large multi-subunit complexes) - 8What are 3 methods to determine protein structure?X-ray crystallography
NMR spectroscopy
Cryo-electron microscopy - 9What are 9 protein functions?enzyme
transport
motor
storage
signal
receptor
gene regulation
specialised (antibodies and toxins) - 10What are the 2 structures between secondary and tertiary?motif/ supersecondary = recurring structural features composed of 2+ secondary structural elements
domain= segment of protein structure that is autonomously stable tertiary structure - 11How do proteins function in cells?protein-ligand interactions= involves the binding of the protein motifs and domains to their corresponding ligand
- 12What is the function of SH2 domain?bind to small peptides containing phosphorylated Tyr's and are used for cellular functions
- 13What is EGFR?epidermal growth factor receptor
regulates key processes of cell biology - 14What are recombinant proteins?a protein obtained by introducing recombinant DNA into a host and causing it to produce the gene product
- 15What are 3 advantages and 3 disadvantages of recombinant protein production in E.coli?Advantages
E.coli genetics are well understood
Almost unlimited quantities of proteins can be generated
Fermentation technology is well understood
Disadvantages
Foreign proteins produced as inclusion bodies must be refolded
Proteins cant be folded in ways needed for many proteins active in mammalian system
some proteins are inactive in humans - 16What are the 4 main steps in column protein purification?1) Protein mixture is applied to the column
2) Solvent buffer applied to top, flowed through the column
3) Proteins interact with the matrix to different extents, flow at different rates
4) Collected separately in different fractions - 17What are 3 protein molecular properties alter the purification method used?protein size- gel filtration
protein-specific binding- affinity chromatography
protein charge-ion exchange - 18How do you find Vt?Vo + Vi
- 19Whats the difference in equations when finding Kav of small and large molecules?Large
Kav = (Vo - Vo) / (Vt - Vo) = 0
Small
Kav = (Vt - Vo) / (Vt - Vo) = 1 - 20What is the equation to find Kav?Kav = (Ve - Vo) / (Vt - Vo)
- 21What is a His-tag protein purification?...a string of histoine residues at the N or C terminus of recombinant protein
- 22What is the isoelectric point (pI)?The pH where the overal protein charge xists largely in a neutral form
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- FlashCards sobre Sem título, criado por Elouisa Rewbicke em 12-12-2019.
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- Elouisa Rewbicke
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