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Multiple choice /True-false (2pts each, 40pts total) order to visualize all prot

ID: 135747 • Letter: M

Question

Multiple choice /True-false (2pts each, 40pts total) order to visualize all proteins present in a sample in which process: are separated by size (with the smaller proteins traveling farther a. velocity sedimentation b. differential sedimentation c a yeast 2-hybrid system d. 2-D electrophoresis (SDS-PAGE) e. Western blotting f. gel-filtration chromatography 2. Isolation of intact organelles would most likely be accomplished using a. velocity sedimentation b. differential sedimentation c. a yeast 2-hybrid system d. 2-D electrophoresis (SDS-PAGE) e. Western blotting f. gel-filtration chromatography 3. Addition of ß-me to a protein sample will: a. reversibly break all non-covalent bonds in any protein b. irreversibly break all non-covalent bonds in any protein c. break all covalent bonds in any protein d. break specific covalent bonds between specific amino acid side chains e. only affect proteins that need a chaperone 4. Which of the following could cause a protein to misfold? a. mutation b. association with a misfolded protein c. change in pH or temperature d. any of the above 5. Groups of closely related proteins, similar in sequence, structure, or both, are called , and members of this group (within a single species) are called a. protein domains, orthologs b. protein families, orthologs c. protein domains, paralogs d. protein families, paralogs

Explanation / Answer

Answer-

1.Denatured proteins are separated by size in order to visualize all proteins present in a sample

d]2-D-electrophoresis

explaination-2-D electrophoresis is technique used for the visualization of proteins which are denatured.in this technique two dimensions are used i.e. one is Isoelectric focusing and second is SDS-PAGE.

after completion of electrophoresis the proteins are visualised in the form of bands.

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2.Isolation of intact organelles would most likely be accomplished using

b]Differential sedimentation

Explaination-Differential sedimentation is widely used analytical method that produces extremely high resolution.

is based upon rates of sedimentation of particles of varying density.

The larger denser particles have a higher rate of sedimantation.

example- nuclei is dense sedements first,then mitochondria,choloroplast,lysosomes,peroxisomes,microsomes,ribosomes and cytosol sediments rspectively.

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3.Addition of beta mercaptoethanol to a protein sample will

d.Breaks specific covalent bonds between specific amino acid side chains.

Explaination- Beta mercaptoethanol is acts as a reducing agent and is used to break the disulfide bonds in proteins .

Disulfide bonds are an example of covalent bond.that is formed between specific amino acid side chains.

Hence d.is correct option.

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