Biochemistry : Globular and Fibrous Proteins

Study concepts, example questions & explanations for Biochemistry

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Example Questions

Example Question #1 : Globular And Fibrous Proteins

Which proteins are generally water-soluble?

Possible Answers:

Neither globular nor fibrous proteins

Both globular fibrous proteins

Fibrous proteins

Globular proteins

Correct answer:

Globular proteins

Explanation:

In a globular protein, the amino acid chain can twist in a way that polar groups lie at the protein's surface. This allows the protein to interact with water and enhances the protein's solubility in water. This does not occur in fibrous proteins, so fibrous proteins are insoluble in water.

Example Question #2 : Globular And Fibrous Proteins

Which of the following is false about actin filaments?

Possible Answers:

Nucleotide hydrolysis promotes dissociation of actin filaments

They require GTP for assembly

2 microfilaments combine to make a coiled filament

Growth of the actin chain occurs at the plus (+) end

They are made up of G-actin

Correct answer:

They require GTP for assembly

Explanation:

Actin chain growth occurs at the (+) end of the chain, and nucleotide hydrolysis promotes dissociation of actin chains. 2 microfilaments of G-actin monomers make 1 filament of F-actin. However, actin filament assembly is powered by ATP, not GTP. 

Example Question #11 : Protein Structure And Functions

An O-linked glycoprotein has a sugar attached to an oxygen atom on what amino acid(s)?

Possible Answers:

Serine only

Methionine only

Serine or threonine

Threonine only

Methionine or threonine

Correct answer:

Serine or threonine

Explanation:

An O-linked glycoprotein is a protein that has a sugar attached to it. It is called O-linked because the sugar is attached to an oxygen atom on either a threonine residue or a serine residue within the protein.

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