Master Bio: The Working Cell Review 1

Which statement best describes phagocytosis? Cells use this process to export products such as insulin or thyroxine. A receptor on the plasma membrane binds to a molecule, and the cell engulfs both the receptor and the molecule. A cell engulfs a particle by wrapping pseudopodia around it and packaging it within a vacuole. Small droplets of extracellular fluid and all the dissolved solutes enter the cell by this process.

A cell engulfs a particle by wrapping pseudopodia around it and packaging it within a vacuole.

Which of the following statements regarding active transport is false?Active transport can move a solute against its concentration gradient. Active transport is driven by the concentration gradient. Active transport requires the cell to expend energy. Active transport uses ATP as an energy source.

Active transport is driven by the concentration gradient.

Green olives may be preserved in brine, which is a 20-30% salt solution. How does this method prevent contamination by microorganisms? Bacterial cell walls are shriveled up by salt, causing the cell to burst. High salt concentrations raise the pH, thus inhibiting the process of glycolysis. Bacteria can't survive in a hypertonic solution because they lose water. High salt concentrations lower the pH, thus inhibiting the process of glycolysis.

Bacteria can't survive in a hypertonic solution because they lose water.

Which of the following statements regarding diffusion is false?Diffusion is a result of the thermal energy of atoms and molecules. Diffusion occurs even after equilibrium is reached and no net change is apparent. Diffusion occurs when particles spread from areas where they are less concentrated to areas where they are more concentrated. Diffusion requires no input of energy into the system.

Diffusion occurs when particles spread from areas where they are less concentrated to areas where they are more concentrated.

Which of the following statements regarding membrane protein function is false? Membrane proteins act as receptors to molecules like hormones. Membrane proteins transfer genetic information to the cytoplasm. Membrane proteins form junctions between cells. Membrane proteins serve as enzymes.

Membrane proteins transfer genetic information to the cytoplasm.

Which of the following substances would have the most trouble crossing a biological membrane by diffusing through the lipid bilayer? O2 a small, nonpolar molecule such as butane (C4H10) CO2 Na+

Na+

Which of the following statements is true for all types of passive transport? Ions never cross the plasma membrane by passive transport. The concentration gradient is the driving force. Only small polar molecules are able to cross the plasma membrane. Proteins are needed to transport molecules across the membrane.

The concentration gradient is the driving force.

In the lab, you use a special balloon that is permeable to water but not sucrose to make an "artificial cell." The balloon is filled with a solution of 20% sucrose and 80% water and is immersed in a beaker containing a solution of 40% sucrose and 60% water. Which of the following will occur? Sucrose will leave the balloon. Sucrose will enter the balloon. Water will leave the balloon. Water will enter the balloon.

Water will leave the balloon.

Utah's Great Salt Lake has an average salinity seven times higher than that of the oceans. Very few multicellular organisms live in this harsh environment. An example is the brine shrimp, which must devote a large portion of its metabolic energy to osmoregulation. These brine shrimp must _____. actively pump salt back out of their cells to counter its inflow due to osmosis actively pump water back into their cells to counter its loss due to osmosis actively pump water back out of their cells to counter its inflow due to osmosis synthesize membranes that are impermeable to substances that upset osmotic balance

actively pump water back into their cells to counter its loss due to osmosis

Living systems decrease their entropy while increasing the entropy of the universe. violate the second law of thermodynamics. violate the first law of thermodynamics. are examples of a closed system.

decrease their entropy while increasing the entropy of the universe.

The movement of atoms, ions, or molecules from a region of higher concentration to regions of lower concentration is called _____. spontaneous combustion crenation active transport diffusion

diffusion

A plant cell placed in a(n) _______ solution will lose water and plasmolyze.

hypertonic

There is a net diffusion of water out of an animal cell when it is placed in a(n) ______ solution.

hypertonic

An animal cell placed in a(n) _______ solution will gain water, swell, and possibly burst.

hypotonic

The ideal osmotic environment for a plant cell is a(n) ______ environment.

hypotonic

1. The ideal osmotic environment for an animal cell is a(n) _________ environment.

isotonic

A plant cell surrounded by a(n) _______ solution will be flaccid (limp).

isotonic

When molecules move down their concentration gradient, they move from where they are _______ to where they are _______

more concentrated, less concentrated

Diffusion across a biological membrane is called __________.

passive transport

Most of the functions of a cell membrane, including transport and enzymatic function, are performed by glycolipids. proteins. phospholipids. cholesterol.

proteins

Overall, membranes seem to have a great deal in common, but on closer inspection it is revealed that membranes of different cells have unique properties. What is the primary component of membranes that gives membranes cell-specific properties? cholesterol phospholipids cytoskeleton proteins

proteins

Which of the following enables a cell to pick up and concentrate a specific kind of molecule? diffusion receptor-mediated endocytosis osmosis passive transport

receptor-mediated endocytosis osmosis

When placed in a hypotonic environment, where the solute concentration is below that of the cell, a houseplant will _____. remain standing upright die go limp and lifeless go brown at the edges of its leaves

remain standing upright

The lipids in a cell membrane are arranged _____. so that the nonpolar parts of two lipids point toward each other so that the hydrophilic components are arranged to face each other on either side of a single layer of protein between two layers of protein

so that the nonpolar parts of two lipids point toward each other

What controls the direction of a molecule, such as oxygen, involved in passive transport? the size of the oxygen molecule the amount of energy available to transport oxygen the direction of the oxygen concentration gradient the type of cell to or from which the oxygen molecule is moving

the direction of the oxygen concentration gradient

According to ________, energy cannot be created or destroyed. the first law of thermodynamics Aristotle's first principle the second law of thermodynamics the third law of thermodynamics

the first law of thermodynamics

Plasma membranes are selectively permeable. This means that anything can pass into or out of a cell as long as the membrane is intact and the cell is healthy. the plasma membrane allows some substances to enter or leave a cell more easily than others. glucose cannot enter the cell. plasma membranes must be very thick.

the plasma membrane allows some substances to enter or leave a cell more easily than others.