Quiz Review Session

Which of the following statements best describes the mechanism by which size exclusion chromatography (SEC) separates biomolecules?

• Smaller molecules elute first because they diffuse more quickly through the mobile phase, while larger molecules elute later due to steric hindrance within the column matrix.

• Larger molecules elute first because they cannot enter the porous beads of the stationary phase, traveling a shorter path. Smaller molecules enter the pores and take longer to elute.

• Smaller molecules interact more strongly with the charged column matrix, leading to delayed elution compared to larger molecules.

• Separation is driven by hydrophobic interactions, where molecules with more hydrophobic regions elute later because of increased interactions with the column.

Which of the following correctly represents what SDS stands for?

• Sodium dodecyl sulfoxide – a detergent that denatures proteins while preserving their native charge.

• Sodium dodecyl sulfide – a reducing agent that breaks disulfide bonds to linearize proteins for electrophoresis.

• Sodium dodecyl sulfate – a surfactant that helps proteins retain their tertiary structure during electrophoresis.

• Sodium dodecyl sulfate – an anionic detergent that denatures proteins and creates a uniform negative charge, dissociates noncovalently bound subunits, and denatures proteins.

Galactose is a C4 epimer of glucose, which of these is D-galactose?

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Carbohydrates have distinct structural variations that influence their biological function. Which of the following statements about carbohydrate structure is correct?

• Monosaccharides are linked by peptide bonds to form polysaccharides, which serve as structural and energy-storage molecules.

• Anomers are a type of enantiomer that differ in configuration at the anomeric carbon formed during ring closure of a monosaccharide.

• Anomers are a type of diastereomer that differ in configuration at the anomeric carbon formed during ring closure of a monosaccharide.

•  D- and L- isomers of a monosaccharide with the same common name (ie glucose) differ in configuration at all chiral carbons, making them diastereomers rather than enantiomers.

Which of the following carbons is the anomeric carbon?

• B)

• C)

• D)

• F)

• A)

Which of the following carbons is the anomeric carbon?

• B)

• E)

• D)

• F)

• A)

Below is an image of the disaccharide Maltose. Where are the anomeric carbons?

• A) 1 and 1’

• B) 1 and 4’

• C) 4 and 1’

• D) 1 and 6’

The image shows the disaccharide maltose. Explain why or why not maltose is a reducing sugar?

• Maltose is a reducing sugar because one of its glucose units has a free anomeric carbon that can open to form an aldehyde group.

• Maltose is a reducing sugar because both glucose units are linked through their anomeric carbons, leaving no free aldehyde group.

• Maltose is not a reducing sugar because it is a disaccharide and all disaccharides are non-reducing.

• Maltose is not a reducing sugar because its glycosidic bond prevents the presence of any reactive functional group.

Tags

NGSS.HS-PS1-2

NGSS.HS-PS1-4

Which of the following is glyceraldehyde?

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Tags

NGSS.HS-LS1-6

True or false: pyranose sugars contain a five membered ring and furanose sugars contain a six membered ring?

• A) True

• B) False