BSC 1005 chapter 5

Which of the following molecules spontaneously form membranes when mixed in water and most likely were one of the first organic compounds formed on Earth?

Phospholipids

A rock on the top of a mountain contains ________ energy.

potential

Humans convert approximately ________ of the energy stored in food to useful work.

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. Which is the correct order of balloon volumes at equilibrium, from largest to smallest?

A < B < C < D

The figure below shows that ________.

ATP can perform cellular work when it releases a phosphate group

Which one of the following is TRUE?

Enzymes catalyze specific reactions.

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

chemical energy into kinetic energy

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 hypotonic to the protozoan

Diffusion ________.

proceeds until equilibrium is reached

Osmosis can be defined as ________.

the diffusion of water across a selectively permeable membrane