AP®︎ Biology: Topic 2.3 Practice Test
Prepare for your quiz, test, or the AP exam with focused practice questions on Topic 2.3 of AP Biology – Plasma Membrane.
Questions List
Topic 2.3
Question 1 Easy
This question tests the following: ENE-1.B
What does a high surface area-to-volume ratio help cells do?
What You’re Being Tested On:
Explore the learning objectives taken directly from the College Board’s AP® Biology Curriculum. Ensure you’re prepared for the exact topics covered on the AP® exam, in-class tests, and quizzes, and gain confidence in your mastery of the material.
Topic 2.3: Plasma Membrane
Learning Objective: 2.3.A
Describe the roles of each of the components of the cell membrane in maintaining the internal environment of the cell.
Essential Knowledge: 2.3.A.1
Phospholipids have both hydrophilic and hydrophobic regions. The polar hydrophilic phosphate regions of the phospholipids are oriented toward the aqueous external or internal environment, while the nonpolar hydrophobic fatty acid regions face each other within the interior of the membrane.
Essential Knowledge: 2.3.A.2
Embedded proteins can be hydrophilic (with charged and polar side groups), hydrophobic (with nonpolar side groups), or both. i. Hydrophilic regions of the proteins are either inside the interior of the protein or exposed to the cytosol (cytoplasm). ii. Hydrophobic regions of proteins make up the protein surface that interacts with the fatty acids in the interior membrane.
Learning Objective: 2.3.B
Describe the fluid mosaic model of cell membranes.
Essential Knowledge: 2.3.B.1
Plasma membranes consist of a structural framework of phospholipid molecules embedded with proteins, steroids (such as cholesterol in vertebrate animals), glycoproteins, and glycolipids. All of these can move around the surface of the cell within the membrane, as illustrated by the fluid mosaic model.
