The plasma membrane is selectively permeable. Which of the following can pass freely through the membrane with no assistance?
oxygen and carbon dioxide
In oil-based liquids, phospholipids are arranged so that their _____ face outward and their _____ are orientated inward.
hydrophobic tails, hydrophilic heads
The movement of molecules from an area of higher concentration to an area of lower concentration is called _____.
When water moves toward the solution with the _____ solute concentration, the solution is _____.
Our cells require glucose to produce energy. Consider a cell where the external concentration of glucose has dropped to 5%, but the internal concentration is at 20%. How does the cell obtain more glucose?
Energy can be classified as either potential or kinetic. Which of the following is an example of kinetic energy?
a hot cup of coffee
Reactions can be exergonic or endergonic. Which of these reactions is endergonic?
Through an _____ reaction, ATP is hydrolyzed into ADP by _____ and _____ energy.
exergonic, losing a phosphate group, releasing
During enzymatic reactions, substrates are converted to products. A property of enzymes that facilitates this reaction is that they are catalysts and therefore ____
change the rate of a reaction without being consumed by the reaction
Lactase is essential for digesting lactose in milk. This enzyme is specific for this sugar. Why?
There is a precise compatibility between the active site and the lactose molecule.