Cell Membrane Structure and Function

Which characteristic of phospholipids is most responsible for their spontaneous assembly into bilayers?

The two leaflets of the plasma membrane always maintain a symmetrical distribution of phospholipids to ensure uniform membrane properties.

Briefly explain how the presence of cholesterol affects the fluidity of an animal cell membrane at different temperatures.

In plant cells, the structural strength provided in addition to the plasma membrane is from a carbohydrate-based cell __________.

Match the following lipids with their primary function or characteristic within cell membranes:

Which of the following factors contributes most significantly to the formation of lipid rafts within the plasma membrane?

Saturated fatty acid tails in phospholipids increase membrane fluidity due to their inability to pack tightly together.

Explain how the asymmetric distribution of phospholipids in the plasma membrane leaflets contributes to cell signaling.

The presence of a cis double bond in the unsaturated fatty acid tail of a phospholipid introduces a __________ in the tail, enhancing membrane fluidity.

How do plant cells compensate for the lack of cholesterol in their plasma membranes to maintain membrane integrity?

Which of the following is the MOST direct consequence of amphotericin B and nystatin binding to ergosterol in fungal cells?

The endoplasmic reticulum (ER) membrane is initially asymmetric, and this asymmetry is directly inherited by the plasma membrane.

Briefly explain how the amphiphilic nature of phospholipids drives the self-assembly of lipid bilayers in aqueous environments.

In the fluid mosaic model, the 'fluid' aspect refers to the ability of membrane components to move _________ within the plane of the membrane.

Match each antifungal drug with its mechanism of action:

Which of the following lipid components is predominantly found in the outer leaflet of the plasma membrane?

The presence of cholesterol in the plasma membrane always decreases membrane fluidity, regardless of temperature.

Describe a specific function of membrane proteins that contributes to cell communication or interaction with the external environment.

The conversion of a symmetric ER membrane into an asymmetric plasma membrane involves the action of enzymes called _________ that selectively transfer specific phospholipids to different leaflets.

Which of the following BEST explains why ergosterol is an effective target for antifungal drugs?

Which of the following characteristics distinguishes integral membrane proteins from peripheral membrane proteins?

What is the primary function of cellulose in the plant cell wall, and what property does it provide?

The structural rigidity of the plant cell wall allows for the generation of a large internal pressure known as ______ pressure.

Match the following components of the plant cell wall with their primary function:

What would happen to a plant cell without a cell wall when placed in a hypotonic solution?

Which of the following is NOT a component of the plant cell wall?

Animal cells possess a cell wall that provides structural support and prevents them from bursting in hypotonic environments.

Describe the role of turgor pressure in plant cell expansion, especially during growth.

Which lipid type is most abundant in plasma membranes?

The presence of a cis double-bond in the hydrocarbon tail of a phospholipid decreases membrane fluidity.

What is the structural characteristic that defines a molecule as amphipathic?

In animal cell membranes, the major sterol present is ________.

What is the primary function of sterols, such as cholesterol, in the plasma membrane?

How do plant cells differ from animal cells regarding membrane sterols?

Saturated hydrocarbon tails in phospholipids generally increase membrane fluidity compared to unsaturated tails.

Which of the following molecules would you expect to diffuse freely through the plasma membrane?

Why is ergosterol a useful target for antifungal drugs?

Amphotericin B and nystatin inhibit ergosterol synthesis, blocking fungal cell growth.

Describe how the amphiphilic nature of phospholipids contributes to the self-assembly of lipid bilayer membranes.

According to the fluid mosaic model, the plasma membrane is considered a fluid because of the ability of its components to move ________ within the membrane.

What is the origin of asymmetry in the plasma membrane?

Match the membrane lipid with its location:

Which of the following is NOT a key function provided by membrane proteins?

Describe how the asymmetric distribution of lipids in the plasma membrane contributes to cell function. Provide a specific example.

Which type of membrane protein is embedded within the lipid bilayer, potentially spanning both leaflets?

What is the main component of the plant cell wall that provides tensile strength?

In plant cells, turgor pressure is generated due to the influx of water via ______.

Match the following membrane structures with their descriptions:

Animal cells rely on turgor pressure for structural rigidity, similar to plant cells.

Which component of the plant cell wall provides waterproofing and is often found in woody tissues?

Explain how turgor pressure contributes to plant cell growth.

The tensile strength of cellulose in the plant cell wall is comparable to ______.

Explain how the amphipathic nature of phospholipids contributes to the formation of the plasma membrane's bilayer structure.

Why do unsaturated fatty acids increase membrane fluidity?

How would a plasma membrane adapt to maintain its fluidity in colder temperatures?

What is the role of sterols, such as cholesterol, in the plasma membrane?

Predict what would happen to a cell if its plasma membrane suddenly lost its selective permeability.

What are lipid rafts and how do they contribute to the function of the plasma membrane?

Explain why the distribution of phospholipids is asymmetric in the plasma membrane.

Contrast the main function of the plasma membrane in animal cells versus the function of the plant cell wall in plant cells.

Explain why the amphiphilic nature of phospholipids is crucial for the self-assembly of biological membranes, and what would happen if phospholipids were purely hydrophobic?

How does the 'fluid mosaic' model describe the structure of the plasma membrane, and what components contribute to its fluidity and mosaic nature?

Describe how the asymmetry of the plasma membrane is established, starting from the symmetric ER membrane, and provide one functional implication of this asymmetry.

Based on the information provided, how do antifungal drugs like amphotericin B and miconazole target fungal cells, and why are these drugs relatively safe for animal cells?

Outline the various functions that membrane proteins carry out within the plasma membrane, giving at least three distinct examples.

Imagine a cell needs to increase its membrane fluidity in response to colder temperatures. Describe two specific changes it could make to the lipid composition of its plasma membrane to achieve this.

If a researcher introduces a protein that disrupts lipid rafts within a cell membrane, what potential effects might this have on cellular processes, and why?

Explain how the structure of a transmembrane protein determines its integration into the lipid bilayer, and what types of amino acids would be most likely found within the region of the protein that spans the membrane?

Describe two distinct ways integral membrane proteins can interact with the lipid bilayer.

Briefly describe the composition of the plant cell wall.

Explain how turgor pressure is generated in plant cells and why it is important.

How does the plant cell wall prevent a plant cell from bursting in a hypotonic environment?

What role does cellulose play in the plant cell wall, and what property does it provide?

Explain how the arrangement of cellulose and pectin contributes to the overall strength and flexibility of the plant cell wall.

Explain why animal cells do not have turgor pressure like plant cells.