Chapter Questions
___________ is the main source of energy for the world of life.a. Foodb. Waterc. Sunlightd. ATP
Which of the following statements is not correct?a. Energy cannot be created or destroyed.b. Energy cannot change from one form to another.c. Energy tends to disperse spontaneously.
If we liken a reaction to an energy hill, then a reaction that __________ is an uphill run.a. requires energyb. releases energyc. runs backwardd. uses an enzyme and a cofactor
In an energy-requiring reaction, activation energy is a bit like ___________.a. a burst of speed at the top of a reactionb. products coasting downhillc. a hill that reactants must climb
Enzymes _______ a. are proteins, except for a few RNAsb. lower the activation energy of a reactionc. are changed by participating in a reactiond. a and b
Name an environmental factor that influences enzyme function.
A metabolic pathway __________.a. may build or break down moleculesb. generates heatc. can include an electron transfer chaind. all of the above
Which of the following statements is not correct?a. Some metabolic pathways are cyclic.b. Glucose can diffuse directly through a lipid bilayer.c. All coenzymes are cofactors.d. Osmosis is an example of diffusion.
A solute tends to diffuse from a region where it is __________ concentrated to another where it is __________ concentrated.a. more, lessb. less, more
__________ cannot diffuse directly through a lipid bilayer.a. Waterb. Gasesc. Ionsd. Nonpolar molecules
Immerse a human red blood cell in a hypotonic solution, and water __________.a. diffuses into the cellb. diffuses out of the cellc. shows no net movementd. moves in by endocytosis
Internal fluid pressure against a cell wall or membrane is called ___________.a. osmosisb. turgor pressurec. diffusiond. osmotic pressure
A transport protein requires ATP to pump sodium ions across a membrane. This is a case of __________.a. passive transportb. active transportc. facilitated diffusiond. osmosis
Vesicles form in ___________.a. endocytosisb. exocytosisc. phagocytosisd. all of the above
$$ \text {reactant } \quad \quad \text {a. assists enzymes} $$$$ \text {phagocytosis} \quad \quad \text {b. forms at reaction's end} $$$$ \text {first law of thermodynamics} \quad \quad \text {c. enters a reaction} $$$$ \text {product} \quad \quad \text {d. currency in a cell's energy economy} $$$$ \text {cofactor} \quad \quad \text {e. one cell "eats" another} $$$$ \text {concentration gradient} \quad \quad \text {f. energy cannot be created or destroyed} $$$$ \text {passive transport} \quad \quad \text {g. motivates diffusion} $$$$ \text {cyclic pathway} \quad \quad \text {h. no energy input required} $$$$ \text {ATP} \quad \quad \text {i. goes in circles} $$