Cell Biology

6 years ago

Refer to Figure 3.1. Which level of structure is being maintained by the disulfide bond?

Refer to Figure 3.1. Which level of structure is being maintained by the disulfide bond?
A) primary
B) secondary
C) tertiary
D) quaternary

pkclary 32 1 Reply

6 years ago

Which term best describes the protein in Figure 3.1?

Which term best describes the protein in Figure 3.1?
A) peripheral
B) external
C) internal
D) integral

Dugg 65 1 Reply

6 years ago

The aquaporin family of proteins plays a major role in the transport of water all over the body. ...

The aquaporin family of proteins plays a major role in the transport of water all over the body. During the folding process of these proteins, α-helices start forming as
A) part of the primary structure of the protein.
B) part of the secon

pkclary 62 1 Reply

6 years ago

Which of the following answers best describes the above metabolic pathway?

Which of the following answers best describes the above metabolic pathway?
A) Anabolic; endergonic
B) Catabolic; endergonic
C) Anabolic; exergonic
D) Catabolic; exergonic

pkclary 44 1 Reply

6 years ago

Which aspect of phospholipids is most important to the formation of bilayers?

Which aspect of phospholipids is most important to the formation of bilayers?
A) They are amphipathic.
B) Their size is large, relative to cholesterol.
C) Their size is small, relative to fats.
D) Their hydrocarbon tails can consi

dracko 86 1 Reply

6 years ago

Which of the following increases the strength of the hydrophobic interactions in lipid bilayers and ...

Which of the following increases the strength of the hydrophobic interactions in lipid bilayers and thus makes them less permeable to polar molecules?
A) the presence of double bonds
B) increasing temperature
C) removing cholesterol

dracko 62 1 Reply

6 years ago

Which of the following crosses lipid bilayers the fastest?

Which of the following crosses lipid bilayers the fastest?
A) a sodium ion
B) a small, polar molecule like water
C) a large, polar molecule like glucose
D) a small, nonpolar molecule like oxygen (O2)

ceybe 44 1 Reply

6 years ago

Which of the following crosses lipid bilayers the slowest?

Which of the following crosses lipid bilayers the slowest?
A) a sodium ion
B) a small, polar molecule like water
C) a large, polar molecule like glucose
D) a small, nonpolar molecule like oxygen (O2)

dracko 46 1 Reply

6 years ago

Why does cholesterol lower membrane permeability?

Why does cholesterol lower membrane permeability?
A) It is polar.
B) It fills gaps in membranes and increases hydrophobic interactions.
C) It participates in hydrogen bonding in the membrane interior.
D) It is small relative to mo

ceybe 57 1 Reply

6 years ago

You have a planar bilayer with equal amounts of saturated and unsaturated phospholipids. After ...

You have a planar bilayer with equal amounts of saturated and unsaturated phospholipids. After testing the permeability of this membrane to glucose, you increase the proportion of unsaturated phospholipids in the bilayer. What will happen to the memb

pkclary 49 1 Reply

6 years ago

You have a planar bilayer at a relatively warm temperature. After testing the permeability of this ...

You have a planar bilayer at a relatively warm temperature. After testing the permeability of this membrane to glucose, you increase the quantity of cholesterol in the bilayer. What will happen?
A) You can't predict the outcome. You simply

dracko 48 1 Reply

6 years ago

The text states that ribonucleotides can diffuse through some types of liposomes. It's likely that ...

The text states that ribonucleotides can diffuse through some types of liposomes. It's likely that the lipids present early in chemical evolution had short chains. Would liposomes formed from these types of lipids be more or less permeable to ri

pkclary 64 1 Reply

6 years ago

What will happen to a red blood cell (rbc), which has an internal ion concentration of about 0.9 ...

What will happen to a red blood cell (rbc), which has an internal ion concentration of about 0.9 percent, if it is placed into a beaker of pure water?
A) Nothing.
B) The cell would shrink because the water in the beaker is hypotonic relativ

dracko 76 1 Reply

6 years ago

Under what circumstances does membrane transport always require energy?

Under what circumstances does membrane transport always require energy?
A) whenever molecules are moved that are too large to pass through the phospholipid bilayer membrane
B) whenever a solute needs to be moved from low concentration to hi

ceybe 59 1 Reply

6 years ago

What is the most important factor in explaining why diffusion occurs spontaneously?

What is the most important factor in explaining why diffusion occurs spontaneously?
A) It leads to an increase in entropy.
B) It leads to a decrease in entropy.
C) The process is exothermic.
D) The process is endothermic.

dracko 61 1 Reply

6 years ago

What is the most important factor in explaining why osmosis occurs spontaneously?

What is the most important factor in explaining why osmosis occurs spontaneously?
A) It leads to an increase in entropy.
B) It leads to a decrease in entropy.
C) The process is exothermic.
D) The process is endothermic.

dracko 50 1 Reply

6 years ago

Which of the following is not true of osmosis?

Which of the following is not true of osmosis?
A) It is a special case of diffusion.
B) It is an energy-demanding or "active" process.
C) Water moves from areas of high water concentration to areas of low water concentration.

pkclary 74 1 Reply

6 years ago

Suppose some blood cells were in an isotonic solution. What would happen to them?

Suppose some blood cells were in an isotonic solution. What would happen to them?
A) They would shrink.
B) They would expand.
C) They would remain the same size.
D) The outcome is not predictable.

ceybe 88 1 Reply

6 years ago

The cell membrane is often referred to as asymmetrical or "mosaic". This means that

The cell membrane is often referred to as asymmetrical or "mosaic". This means that
A) both layers of the phospholipid bilayer are not identical in terms of protein type or number and phospholipid type.
B) only certain substances

ceybe 95 1 Reply

6 years ago

What is the name of the currently accepted model of membrane structure, and where does it place ...

What is the name of the currently accepted model of membrane structure, and where does it place membrane proteins?
A) fluid-mosaic; on the surfaces of the membrane only
B) fluid-mosaic; embedded within the membrane and on the surfaces of th

pkclary 45 1 Reply

6 years ago

Which of the following observations made with freeze-fracture electron microscopy provides evidence ...

Which of the following observations made with freeze-fracture electron microscopy provides evidence for the fluid-mosaic model of membrane structure?
A) The middle of the membrane viewed under the electron microscope was smooth and regular.

dracko 60 1 Reply

6 years ago

Integral membrane proteins stay in membranes because of

Integral membrane proteins stay in membranes because of
A) osmotic pressure from proteins outside the cell.
B) diffusion of proteins from the cytoplasm to the membrane.
C) the locations of their polar and nonpolar amino acids.
D)

Dugg 105 1 Reply

6 years ago

Where would you most likely find an integral membrane protein?

Where would you most likely find an integral membrane protein?
A) on the inside surface of the cell membrane
B) on the outside surface of the cell membrane
C) floating freely in the cytoplasm
D) spanning the cell membrane, with pa

Dugg 96 1 Reply

6 years ago

To determine if membrane proteins affect membrane permeability, you could isolate the proteins from ...

To determine if membrane proteins affect membrane permeability, you could isolate the proteins from the lipid components of the membrane by using detergents. Then you could separate the individual proteins and test each of them in a planar bilayer. W

Dugg 138 1 Reply

6 years ago

Which of the following means of transport would most likely be used for moving a medium-sized ...

Which of the following means of transport would most likely be used for moving a medium-sized molecule (like a monosaccharide or an amino acid) from a low concentration on the outside of a cell to a high concentration on the inside of a cell?
A)

pkclary 62 1 Reply

6 years ago

Amoeba move by crawling over a surface (amoeboid movement). Which one of the following processes is ...

Amoeba move by crawling over a surface (amoeboid movement). Which one of the following processes is part of amoeboid movement?
A) polymerization or extension of actin filaments to form bulges in the plasma membrane
B) setting up microtubule

dracko 59 1 Reply

6 years ago

What is the function of keratin, an important intermediate filament?

What is the function of keratin, an important intermediate filament?
A) imparts impermeability to the skin and the ability to withstand mechanical stress
B) reinforces moveable joints
C) enables the heart to contract as a unit
D)

pkclary 49 1 Reply

6 years ago

Researchers tried to explain how vesicular transport occurs in cells by attempting to assemble the ...

Researchers tried to explain how vesicular transport occurs in cells by attempting to assemble the transport components. They set up microtubular tracks along which vesicles could be transported, and they added vesicles and ATP (because they knew the

dracko 56 1 Reply

6 years ago

How is the structure of kinesin related to its function?

How is the structure of kinesin related to its function?
A) Kinesin has two intertwined polypeptides that make up the stalk and enable it to contract and shorten.
B) Kinesin has a tail region that binds to vesicles and two heads that can at

pkclary 110 1 Reply

6 years ago

Motor proteins require energy in the form of ATP. ATP hydrolysis results in a conformational change ...

Motor proteins require energy in the form of ATP. ATP hydrolysis results in a conformational change that allows the protein to move along microtubular tracks (pathways). What structural component of the motor protein contains the ATP binding site and

pkclary 88 1 Reply

6 years ago

Flagella and cilia bend or move, imparting mobility to cells. How do these structures move?

Flagella and cilia bend or move, imparting mobility to cells. How do these structures move?
A) The basal body at the base of the structure hydrolyzes ATP, causing a conformational change that results in movement of the cilium or flagellum.

dracko 114 1 Reply

6 years ago

Flagella are found in both eukaryotic cells and prokaryotic cells. Despite the functional ...

Flagella are found in both eukaryotic cells and prokaryotic cells. Despite the functional similarities of all flagella, scientists suspect that eukaryotic and prokaryotic flagella have evolved independently. Why don't they think there is a commo

pkclary 99 1 Reply

6 years ago

To what does the 9 + 2 arrangement of microtubules, typical of cilia and eukaryotic flagella, ...

To what does the 9 + 2 arrangement of microtubules, typical of cilia and eukaryotic flagella, refer?
A) the arrangement of dynein arms with respect to each microtubule
B) the arrangement of microtubules within the axoneme
C) the length

pkclary 80 1 Reply

6 years ago

Asbestos is a material that was once used extensively in construction. One risk from working in a ...

Asbestos is a material that was once used extensively in construction. One risk from working in a building that contains asbestos is the development of asbestosis. The asbestos fibers can be inhaled. Cells will phagocytose the foreign material but ar

dracko 65 1 Reply

6 years ago

Spherocytosis is a defect associated with a defective cytoskeletal protein in red blood cells. What ...

Spherocytosis is a defect associated with a defective cytoskeletal protein in red blood cells. What do you suspect is one consequence of defective cytoskeletal proteins in red blood cells?
A) abnormal cell shape
B) insufficient energy suppl

dracko 110 1 Reply

6 years ago

Which of the following is a basic structural difference between plant cells and animal cells?

Which of the following is a basic structural difference between plant cells and animal cells?
A) Plant cells contain chloroplasts, but animal cells do not.
B) Animal cells contain lysosomes, but plant cells do not.
C) Plants have cell

pkclary 73 1 Reply

6 years ago

You are sitting in lecture and you decide to leave the room for a minute. When you return, the ...

You are sitting in lecture and you decide to leave the room for a minute. When you return, the professor is describing a cytoskeletal component and states that these fibres are thin and consist of two rows of protein subunits wound around each other

pkclary 79 1 Reply

6 years ago

One characteristic of life and living systems is that they are able to adapt. Toward this end, cells ...

One characteristic of life and living systems is that they are able to adapt. Toward this end, cells interact with other cells and their environment through the action of their
A) plasma membrane and extracellular matrix.
B) microtubular tr

pkclary 53 1 Reply

6 years ago

Plant cells are typically exposed to a hypotonic environment. Therefore, you would expect

Plant cells are typically exposed to a hypotonic environment. Therefore, you would expect
A) a microscopic space between the plasma membrane and the cell wall.
B) occasional contact between the plasma membrane and the cell wall.
C) the

ceybe 56 1 Reply