Biology Pre-Quiz Chapter 5

What is an example of osmosis?

- Water enters a plant by passing through the root cell membranes. (The passive transport of water across a selectively permeable membrane is called osmosis)

Energy is observed in two basic forms: potential and kinetic. What is an example of potential energy?

- A bowling ball placed on the top shelf of a closet (Lifting the bowling ball into place required energy, which is now stored in the ball becuase of its location. Thus, this is an example of potential energy)

The use of energy to move molecules across a membrane defines ______.

- Active transport (Cellular energy is used to drive a transport protein that pumps a solute across a gradient)

What materials are found in molecule of ATP?

- An organic molecule called adenosine plus three phosphate groups (This is the primary structure of adenosine triphosphate)

An enzyme is a protein that ______.

- Changes the rate of a metabolic reaction without being consumed by the reaction (All catalysts, including enzymes, work by accelerating the rates of chemical reactions by lowering the activation energy. Catalysts accelerate the rates of the reactions they catalyze without being consumed by the reaction. This permits enzyme molecules to be used repeatedly)

Molecules of food have a special form of potential energy called _______.

- Chemical energy (Energy is stored in food molecules by arrangment of atoms)

The passive movement of molecules from an area of higher concentration to an area of lower concentration is called ______.

- Diffusion (In diffusion, molecules move down the concentration gradient)

What describes a laboratory technique that scientists might use to mimic a natural genetic process of cells?

- Directed evolution (This laboratory method mimics the natural evolution of enzymes to produce artifical enzymes with new functions)

Calories are units of ______.

- Energy (A calorie is the amount of energy required to increase temperature of 1 gram of water by 1 degree C. Calories can refer to any type of energy, not just heat)

What statment about energy is correct?

- Energy cannot be created or destroyed (The law of conservation of energy states that energy cannot be created or destroyed)

How do some inhibitors slow down metabolic pathways when the products of the pathways are not needed but still allow a pathway to proceed when the products are needed?

- Feedback regulations (Feedback regulations prevents cells from wasting resources that could be put to better use)

In osmosis, water always moves towards the ______ solution, that is, toward the solution with the _____ solute concentration.

- Hypertonic......greater (Water moves by osmosis from the hypotonic solution toward the hypertonic solution)

An animal cell placed in a hypertonic solution will ______.

- Lose water by osmosis and shrivel (The hypertonic solution has a higher concentration of solutes. The causes water to diffuse out of the cell and shrivel)

Entropy means that _______.

- The quality of usable energy declines with each energy transformation (In almost all situations, a significant percentage of the energy involved in a transformation is converted to heat)

What best explains the observation that enzymes are selective in the reactions they catalyze?

- There is a precise compatibility between an enzyme's active site and the substrate molecule (The chemistry and shape of a substrate molecule fit precisely within the enzyme's active site)