AP Bio Midterm Review: Macromolecules Structure & Function

Which list of components characterizes RNA

• A PO₃ group, deoxyribose, and uracil

• A PO_3, ribose, and uracil

• A PO_3, ribose, and thymine

• A PO_3, deoxyribose, and thymine

Which of the following molecules would contain a polar covalent bond?

• Cl₂

• NaCl

• H₂O

• CH₄

Answer explanation

Polar covalent means that the electrons that form the bonds are shared but not shared equally

Three terms associated with the movement of water from the roots up through the vascular tissue of plants:

• adhesion, cohesion, translocation

• adhesion, cohesion, transcription

• cohesion, adhesion, transpiration

• cohesion, adhesion, hybridization

Select the term that is most closely related to the following phrase: "contains one or more double bonds which 'kink' the carbon backbone.

• lipids

• Peptide bonds

• unsaturated fatty acids

• Alpha helix

The process by which protein conformation is is lost or broken down is

• dehydration synthesis

• translocation

• denaturation

• hydrolysis

An organic compound that is composed of carbon, hydrogen, and oxygen in a ratio of 1:2:1.

• Lipids

• Nucleic Acids

• Proteins

• Carbohydrates

Which of the macromolecules below could be structural parts of the cell, enzymes or involved in cell movement or communication?

• carbohydrates

• lipids

• proteins

• nucleic acids

Which macromolecule is the main component of all cell membranes?

• DNA

• phospholipids

• carbohydrates

• steroids

Answer explanation

phospholipids are unique macromolecules. Their hydrophilic heads and hydrophobic tails contribute to the semi-permeability of cell membranes

If three molecules of a fatty acid that has the formula C₁₆H₂₂O₂ are joined to a molecule of glycerol (C₃H₈O₃), then the resulting molecule would have the formula

• C₄₈H₉₆O₆

• C₄₈H₉₈O₈

• C₅₁H₆₈O₆

• C₅₁H₁₀₆O₈

• C₅₁H₁₀₄O₉

Answer explanation

To get this correct, you should first add up all the C,H, and O in three fatty acid chains plus one glycerol. The would be 51C, 74H, and 9O. Then, recall that to join molecules by dehydration synthesis, one molecule of water (H₂O) must be removed. There are four molecules involved here, three molecules of water must be removed. Subtract 6H and 3O to arrive at the correct answer.

The partial negative charge at one end of a water molecule is attracted to a partial positive charge of another water molecule. What is this type of attraction called?

• a polar covalent bond

• an ionic bond

• a hydration shell

• a hydrogen bond