Cell Biology Questions

What is the input of the Calvin cycle?

Where in the cell does photosynthesis take place?

What goes "in" for a light independent reaction?

How does an enzyme increase the speed of a reaction? - by decreasing the concentration of reactants - by providing activation energy - by increasing the concentration of products - by changing an endergonic to an exergonic reaction - by lowering activation energy requirements

A __________ is a process that breaks and forms chemical bonds.

The energy of movement is called __________.

__________ are biological catalysts synthesized by living organisms.

What is predicted by the second law of thermodynamics? - Energy is always decreasing. - Disorder cannot be created or destroyed. - Systems always tend toward greater states of disorder. - All potential energy exists as chemical energy. - all of the above

Which statement about exergonic reactions is true? - The products have more energy than do the reactants. - The reactants have more energy than do the products. - They will not proceed spontaneously. - Energy input reverses entropy. none of the above

The __________ of a cell is the sum of all of its chemical reactions.

ATP is important in cells because - it transfers energy from exergonic reactions to endergonic reactions - it is assembled into long chains that make up cell membranes - it acts as an enzyme - it accelerates diffusion - all of the above

Without energy, processes that proceed spontaneously result in an increase in __________.

Which of the following statements about enzymes is (are) true? - They interact with specific reactants (substrates). - Their three-dimensional shapes are closely related to their activities. - They change the shape of the reactants. - They have active sites. - all of the above

__________ is the most common energy-carrier molecule in cells.

What is the importance of coupled reactions? - Coupled reactions allow an endergonic reaction to drive an exergonic reaction. - Coupled reactions allow an exergonic reaction to drive an endergonic reaction. - Coupled reactions turn potential energy into kinetic energy. - Coupled reactions supply the energy needed to start a reaction.

Why is ATP so important to cells? - ATP hydrolysis is exergonic and can be coupled to endergonic reactions. - ATP hydrolysis is endergonic and can be coupled to exergonic reactions. - ATP lowers the activation energy for an exergonic reaction. - ATP acts as a coenzyme in enzymatically catalyzed reactions.

The amino acid threonine is converted to isoleucine by a sequence of five enzymatic reactions. When isoleucine levels are high, the first reaction in this sequence is "turned off." This is an example of _____. - substrate activation - feedback inhibition - competitive inhibition - coenzyme activation

Which of the following are correct statements about how enzymes work?- Enzymes catalyze specific chemical reactions because the shape of their active site allows only certain substrate molecules to enter. - The substrate(s) enter the enzyme active site in specific orientations. - The enzyme and the substrate(s) change shape, promoting a specific chemical reaction and then allowing the products to leave. - The first three answers are all correct. - Only the first two answers are correct.

The laws of thermodynamics __________. - explain how energy is created and destroyed - refer to fluctuating temperature changes - define the basic properties and behavior of energy - suggest that matter in a disorganized state requires energy to be constantly added to maintain the "disorganization

When electrical energy is used to turn on a light bulb, the conversion from electrical energy to light energy is not 100% efficient. This loss of usable energy can be explained by __________. - the first law of thermodynamics - the second law of thermodynamics - a destruction of energy - a conversion to potential energy