Chapter 5

__________ is life's primary source of energy. a. Food b. Water c. Sunlight d. ATP

If we liken a chemical reaction to an energy hill, then an an __________ reaction is an uphill run. a. endergonic b. exergonic c. ATP-assisted d. both a and c

Energy __________. a. cannot be created o b. can change from one form to another c. tends to disperse spontaneously d. all of the above

Enzyme function is influenced by __________. a. temperature b. \(\mathrm{pH}\) c. salt d. all of the above

Enzymes ___________. a. are proteins, except for a few RNAs b. lower the activation energy of a reaction c. are destroyed by the reactions they catalyze d. a and b

Diffusion is the movement of ions or molecules from one region to another where they are less concentrated. The rate of diffusion is affected by __________. a. temperature b. electric gradients c. solute size d. all of the above

Transporters that require an energy boost help sodium ions across a cell membrane. This is a case of __________. a. passive transport b. active transport c. facilitated diffusion d. a and

Immerse a living human cell in a hypotonic solution, and water will tend to __________. a. diffuse into the cell b. diffuse out of the cell c. show no net movement d. move in by endocytosis

Match each term with its most suitable description. ___________ passive transporter ___________ enzyme ___________ phagocyte at work ___________ product ___________ \(\mathrm{ATP},\) mostly ___________ active transporter ___________ concentration gradient ___________ cofactor ___________ reactant a. assists enzymes b. works against a gradient c. substance that enters a reaction d. energy currency e. enhances reaction rate f. a basis of diffusion g. no energy to help solutes across membrane h. cell engulfing a cell i. there at reaction's end