MCAT Biology : Other Techniques

Study concepts, example questions & explanations for MCAT Biology

varsity tutors app store varsity tutors android store

Example Questions

Example Question #51 : Organic Analyses And Lab Techniques

Which of the following properties can be used to differentiate between enantiomers?

Possible Answers:

Melting temperature

Density

Optical activity

Heat of vaporization

Correct answer:

Optical activity

Explanation:

Chiral molecules are a unique type of isomer, defined as two molecules with inverted stereochemistry, which makes them mirror images of one another. These isomers will ahve the same molecular weight, as well as most physical properties. Enatiomers cannot be distinguished based on melting point, heat of vaporization, or density. The primary, defining characteristic of a chiral molecule is its ability to effect plane polarized light. One isomer will rotate the light to the right, while the other will rotate the light to the left.

Example Question #52 : Organic Analyses And Lab Techniques

Which of the following properties cannot be used to differentiate between myoglobin and hemoglobin?

Possible Answers:

Location

Number of subunits

Affinity for oxygen

Bound reduced iron

Correct answer:

Bound reduced iron

Explanation:

Myoglobin and hemoglobin are the proteins primarily responsible for binding, transporting, and storing oxygen. Myoglobin is primarily located in muscle tissue, and has a very high affinity for oxygen. Hemoglobin is located in the blood, and has a slightly lower oxygen binding affinity. Thus, as hemoglobin carries oxygen past muscle tissue, oxygen can be released and will preferentially bind to myoglobin. Hemoglobin contains four subunits, each capable of binding one oxygen molecule, while myoglobin consists of only one subunit.

Both hemoglobin and myoglobin contain heme units, which structurally and functionally rely on the incorporation of reduced iron. As such, this property cannot be used to differentiate these two proteins.

Example Question #53 : Organic Analyses And Lab Techniques

Which macromolecule is classified by physical properties rather than by monomer?

Possible Answers:

Proteins

Nucleic acids

Lipids

Carbohydrates

Correct answer:

Lipids

Explanation:

Unlike carbohydrates, proteins, and nucleic acids, lipids do not have a uniform monomer structure. Rather, they are classified by their hydrophobic properties and a variety of beasic structural categorizations. Some examples of lipid classifications are glycerophospholipids, sphingolipids, and steroids.

Learning Tools by Varsity Tutors

Incompatible Browser

Please upgrade or download one of the following browsers to use Instant Tutoring: