2.2 Cell Membranes

• The fluid mosaic model describes the cell membrane as a rigid, unmoving structure.

  False
• What factors affect the stability and fluidity of cell membranes?

  Protein composition
• Cholesterol stabilizes membrane fluidity
• The phospholipid bilayer forms the structural framework
• Proteins embedded within the cell membrane can act as channels
• Increased temperature always increases membrane permeability.


  True
• Glycolipids play a role in cell recognition.


  True
• Match the cell membrane component with its role:

  Proteins ↔️ Facilitate transport

  Carbohydrates ↔️ Cell recognition

  Phospholipids ↔️ Structural framework
• The fluid mosaic model emphasizes the dynamic nature of the cell membrane
• Match the cell membrane component with its role:

  Phospholipids ↔️ Structural framework

  Proteins ↔️ Transport and signaling

  Carbohydrates ↔️ Cell recognition
• What is the role of glycolipids and glycoproteins in the cell membrane?

  Cell recognition and adhesion
• What is the primary molecule that moves during osmosis?

  Water
• What type of membrane is necessary for osmosis to occur?

  Semi-permeable
• Secondary active transport uses a pre-existing ion gradient as an energy source to transport another substance
• What is the main structural component of the fluid mosaic model?

  Phospholipid bilayer
• Proteins embedded within the phospholipid bilayer can function as channels, receptors, or enzymes
• Diffusion requires energy to move substances across the cell membrane.

  False
• Membrane fluidity increases as temperature increases.


  True
• A higher proportion of saturated fatty acids in the lipid composition decreases membrane permeability.


  True
• Ion channel receptors open ion channels upon ligand binding
• What are cell membranes and what is their primary function?

  Selective barriers
• Arrange the following membrane transport mechanisms based on their reliance on energy:

  1️⃣ Diffusion

  2️⃣ Osmosis

  3️⃣ Facilitated diffusion

  4️⃣ Active transport
• What is the structural framework of the cell membrane described by the fluid mosaic model?

  Phospholipid bilayer
• What does selective permeability allow cell membranes to control?

  Molecular transport
• Why do hydrophobic tails of phospholipids face inward in the bilayer?

  To create a barrier
• What are proteins embedded within the cell membrane responsible for?

  Transport and communication
• What drives the movement of molecules in diffusion?

  Random molecular motion
• The components of the cell membrane work together to maintain structure and facilitate essential functions.


  True
• Facilitated diffusion uses membrane proteins as channels or carriers to transport molecules across the cell membrane without energy
• What form of energy is required for active transport?

  ATP
• What factors influence membrane stability and fluidity?

  Phospholipid composition, cholesterol, temperature
• The fluid mosaic model describes the cell membrane as static and unchanging.

  False
• Membrane transport mechanisms are crucial for cell survival.


  True
• Match the type of active transport with its energy source:

  Primary active transport ↔️ ATP

  Secondary active transport ↔️ Ion gradient
• Match the factor with its effect on membrane stability:

  Saturated fatty acids ↔️ Stabilizing

  Unsaturated fatty acids ↔️ Fluidizing
• Steps in cell signaling:

  1️⃣ Signaling molecule binds to membrane receptor

  2️⃣ Receptor initiates intracellular events

  3️⃣ Cell responds to the signal
• Membrane receptors allow cells to sense and respond to external signals.


  True
• Cell membranes protect the cell's contents.


  True
• The fluid mosaic model allows for efficient signaling between cells.


  True
• Osmosis is the diffusion of water