1.3 Learning Objectives

Gene Regulation

Draw a phospholipid, identifying polar and nonpolar regions and describe how phospholipids behave in water.

Draw a cell membrane with its four primary components.

Rank the ability of large versus small molecules; polar versus nonpolar molecules; and charged versus uncharged molecules to cross the phospholipid bilayer.

Predict the direction of movement of substances across membranes based on relative concentrations.

Predict whether energy is necessary to move substances either with or against their concentration gradients.

Contrast the fluidity and permeability of a membrane composed of mostly saturated versus unsaturated phospholipids.

Predict how the addition of cholesterol would alter membrane permeability.

Determine the relative concentrations of solute versus water in hyper-, hypo- and isotonic solutions.

Predict the direction of movement of water of cells placed in hyper-, hypo- and iso- tonic environments.

Predict when transport proteins are required to transport substances across a membrane and contrast carrier, channel and pump membrane proteins.