Chapter 5 final review

The beaker in the illustration contains two solutions of salt with different concentrations (measured by molarity, M). The two solutions are separated by a membrane that is permeable to water but not to salt.

diffusion of water from A to B but no diffusion of salt

The random movement of molecules within a solution is referred to as:

diffusion.

The interior region of a phospholipid bilayer is characterized as:

hydrophobic.

A cell has a mutation that prevents it from breaking down unwanted proteins present in vesicles. Which cellular structure is most likely to be disrupted by this mutation?

lysosome

In which eukaryotic organelle are various macromolecules broken down and destroyed?

lysosome

Some diseases, such as Tay-Sachs, are caused by defects in the breakdown of cellular components. Which organelle could be defective with such a disease?

lysosome

The beaker in the illustration contains two solutions of salt with different concentrations (measured by molarity, M). The two solutions are separated by a membrane that is permeable to both salt and water. What will occur in this container?

net diffusion of water from A to B and of salt from B to A

RNA molecules are transported from the nucleus to the cytoplasm in eukaryotes through:

nuclear pores.

Which lipid composition option has the least membrane fluidity?

phospholipids with long-chain, saturated fatty acids

Which choice is considered an integral membrane protein?

a protein with its amino-terminus in the cytoplasm and its carboxy-terminus in the extracellular space Score: 0 of 1

Why does active transport of molecules across a membrane require ATP?

An input of energy is needed to allow the movement of molecules from an area of low concentration to one of higher concentration.

Which statement is true about the presence or absence of plasma membranes?

All cells have a plasma membrane.

How do eukaryotic plant and animal cells differ from one another?

Animal cells do not have chloroplasts and cell walls, and plant cells do.

Prokaryotes absorb their nutrients from the environment. However, many prokaryotes have cell walls. What can you conclude from this information?

Cell walls are permeable, allowing nutrients to pass through.

Some lipid rafts are characterized by an accumulation of cholesterol. What does this mean for the fluidity of the lipid raft?

Cholesterol decreases the fluidity of the membrane at normal temperatures.

How can lysosomal enzymes that work best at a pH of 5 be fully functional if the pH of the cytoplasm is 7?

Lysosomal enzymes are separated from the cytoplasm by the membrane surrounding the lysosome

__________ is not a cellular function of microfilaments.

Movement of motile cilia

_________ is not a cellular function associated with microtubules.

Muscle contraction

Considering the amino acids that are found in various domains of transmembrane proteins, which statement would be true?

Nonpolar amino acids would be prevalent in the transmembrane domain, in contact with the environment of the inner membrane

Molecular oxygen (O2), which is required for the production of ATP by mitochondria, must pass through at least three membranes to get to the enzymes where it is used. O2 is also produced in chloroplasts and must pass through at least four membranes to be released from the plant. How does O2 move across biological membranes?

O2 is nonpolar and very small, so it can move by simple diffusion across the membrane.

Researchers seldom find prokaryotic cells that are greater than 100 micrometers in diameter. Why would the size of prokaryotic cells be restricted?

Prokaryotic cells must absorb all of their nutrients from their environment and therefore require a high surface area to volume ratio.

magine that you have two blades of grass. One is from a normal plant, and the other is from a mutant plant that cannot absorb water into its vacuoles. How will the structures of these two blades of grass compare?

The grass blade from the mutant plant will appear limp compared to that from the normal plant.

A beaker contains two solutions of salt dissolved in water. The two solutions have different concentrations of salt (measured by molarity, M) and are separated by a membrane that is permeable to both salt and water. The salt and water will move through the membrane by diffusion. Which statement is true about the diffusion of these solutions?

There will be a net movement of salt from side B to side A and net movement of water from side A to side B

A bacterial cell, a plant cell, and an animal cell have which structure in common?

a cytoplasm

In response to seasonal changes in temperature, many organisms must alter the composition of their plasma membranes to maintain the proper degree of fluidity. Which change in the fatty acids of phospholipids would be most effective in maintaining membrane fluidity in a colder environment?

a decrease in phospholipid fatty acid side chain length and a decrease in side chain saturation

A cell's plasma membrane contributes to homeostasis by:

acting as a selective barrier.

The plasma membranes of some plant cells use transport proteins to move protons out of the cell against their concentration gradient. This is an example of:

active transport

In order for phospholipids to form bilayers spontaneously in an aqueous environment, the pH should be

approximately neutral

What would be found in the cells of a blade of grass but not in the cells of an insect feeding on that grass?

chloroplasts

An amphipathic molecule is one that:

contains both polar and nonpolar regions.

Which component of a phospholipid is found in the interior of a lipid bilayer?

fatty acids

Which molecules can easily diffuse across a plasma membrane?

gases like O2 and CO2

Disorders of which organelle are often associated with defects in transport from compartment to compartment, resulting in poor sorting of protein components within the cell?

the Golgi apparatus

Which eukaryotic cell structure plays a role in protein trafficking and sorting?

the Golgi apparatus

Which of the structures are part of the endomembrane system of a eukaryotic cell?

the Golgi apparatus and the endoplasmic reticulum

Which part of a cholesterol molecule is polar?

the OH group

Phospholipids spontaneously form a variety of structures in aqueous solution. Which choice best describes this property?

the ability of vesicles to bud off from the plasma membrane (endocytosis) , formation of lipid bilayers, the ability of vesicles to fuse with the plasma membrane (exocytosis), the first cells

The term homeostasis refers to:

the active maintenance of a constant environment within the cell

In which eukaryotic organelle are some macromolecules broken down to obtain useful energy for the cell in the form of ATP?

the mitochondria

Which of the structures are part of the endomembrane system?

the nuclear envelope

The process of diffusion requires:

the random movement of molecules.transport proteins.

Turgor pressure is the result of:

water accumulation within a cell.