Biology Chapter 5

________ occurs when a white blood cell engulfs a bacterium. Diffusion Phagocytosis Exocytosis Osmosis

Phagocytosis

A boulder at the top of a hill contains ________ energy. kinetic no potential conserved

Potential

Which of these types of cellular transport require(s) energy? active transport facilitated diffusion and active transport osmosis facilitated diffusion

active transport

Substances that plug up an enzyme's active site are enzyme ________. substrates catalysts products inhibitors

inhibitors

Diffusion is an example of ________. active transport phagocytosis passive transport endocytosis

passive transport

Which of these molecules spontaneously form membranes when mixed in water and most likely were one of the first organic compounds formed on Earth? RNA DNA enzymes phospholipids

phospholipids

Directed evolution is a relatively new way to engineer enzymes. Previously, scientists tried to design proteins by using computer models to try to predict how specific changes in genetic sequences might result in altered enzyme structure and function. Why is one of these approaches more efficient than the other? 1. Although the computer modeling method is slower and requires more information about the enzyme's genetic sequence 2. Generating high numbers of random mutations and subsequently screening for desired function means that directed evolution requires little prior knowledge of enzyme structure. 3. Because directed evolution produces many genetic sequences that do not lead to improved activity 4. Computer models can produce many possible changes in genetic sequences in a short period of time

2. Generating high numbers of random mutations and subsequently screening for desired function means that directed evolution requires little prior knowledge of enzyme structure.

You have a 2-kg bottle of liquid water at 0°C. About how many Calories are needed to heat up the water to 100°C? 200 Calories 100 Calories 2000 Calories 10000 Calories

200 calories

Humans convert approximately ________ of the energy stored in food to useful work. 55% 99.9% 22% 34%

34%

On a lab bench, there are four balloons filled with identical volumes of different salt solutions: 0% (balloon A), 5% (balloon B), 10% (balloon C), and 15% (balloon D). There are also four beakers each filled with identical volumes of a 10% salt solution. The balloons are semi-permeable; that is, only water can enter and exit the balloon. All four balloons are placed in separate beakers at the same time and are allowed to come to equilibrium. At equilibrium, which is the correct order of balloon volumes from largest to smallest? D C B A A B C D D B A C All balloons will be of equal volume at equilibrium.

A B C D

Which environments would be best for the functioning of animal and plant cells? A hypotonic environment for animal cells and an isotonic environment for plant cells. No option applies A hypotonic environment for plant cells and an isotonic environment for animal cells. An isotonic environment for both plant and animal cells.

A hypotonic environment for plant cells and an isotonic environment for animal cells.

Which process could result in the net movement of a substance into a cell, if the substance is more concentrated in the cell than in the surroundings? osmosis facilitated diffusion diffusion active transport

Active transport

Which statement about enzymes is TRUE? Enzymes catalyze specific reactions. Enzymes are the reactants in a chemical reaction. Enzymes' functions require inhibitors. Enzymes are the products in a chemical reaction.

Enzymes catalyze specific reactions.

You are riding on your bike and stop pedaling, coasting along the road. Eventually, your bike slows down and stops. What happened to the energy of your motion when your bike stopped? It was released as heat. It was converted back to chemical energy. It was used to chemically break down the tires. It was returned to the bicycle.

It was released as heat.

A balloon contains a 10% glucose solution. The balloon is permeable to water but not to glucose. A beaker contains a 5% glucose solution. What will happen when the balloon is submerged in the beaker? The amount of glucose in the beaker will increase. The volume of water in the beaker will increase. The amount of glucose in the beaker will decrease. The volume of water in the beaker will decrease.

The volume of water in the beaker will decrease.

Active transport ________. is a type of facilitated diffusion can involve the transport of ions moves solutes with their concentration gradient does not use ATP as an energy source

can involve the transport of ions

Glucose molecules provide energy to power the swimming motion of sperm. In this example, the sperm are changing ________. kinetic energy into chemical energy chemical energy into potential energy chemical energy into kinetic energy kinetic energy into potential energy

chemical energy into kinetic energy

If someone at the other end of a room smokes a cigarette, you may breathe in some smoke. The movement of smoke is similar to what type of transport? osmosis diffusion active transport facilitated diffusion

diffusion

What molecules are scientists currently trying to use to generate power for nanotechnology devices, such as microscopic robots? cell membranes enzymes lipids DNA

enzymes

Specialized cells that line the stomach synthesize a digestive enzyme and secrete it into the stomach. Which process could be responsible for its secretion? exocytosis endocytosis phagocytosis passive transport

exocytosis

When a person cries, tears are exported from cells. Which category of transport most precisely matches this process? endocytosis exocytosis facilitated diffusion active transport

exocytosis

Some protozoans have special organelles called contractile vacuoles that continually eliminate excess water from the cell. The presence of these organelles tells you that the environment ________. is hypertonic to the protozoan contains a higher concentration of solutes than the protozoan is hypotonic to the protozoan is isotonic to the protozoan

is hypotonic to the protozoan

A cell that neither gains nor loses a net amount of water at equilibrium when it is immersed in a solution is ________. isotonic to its environment hypertonic to its environment hypotonic to its environment metabolically inactive

isotonic to its environment

The sum total of all the chemical reactions that occur in organisms is called ________. conservation of energy metabolism cellular synthesis kinetic energy

metabolism

Diffusion ________. is the result of an energy transformation requires an input of cellular energy occurs when particles spread from areas where they are less concentrated to areas where they are more concentrated proceeds until a dynamic equilibrium is reached

proceeds until a dynamic equilibrium is reached

An enzyme's function is most dependent on its ________. temperature activation energy size shape

shape

Osmosis can be defined as ________. the diffusion of any small molecule across a selectively permeable membrane the diffusion of water across a selectively permeable membrane the diffusion of a solute across a selectively permeable membrane active transport across a selectively permeable membrane

the diffusion of water across a selectively permeable membrane

Facilitated diffusion across a biological membrane requires ________ and moves a substance ________ its concentration gradient. energy; down transport proteins; against energy and transport proteins; against transport proteins; down

transport proteins; down