2.5.1 Membrane structure

• Biological membranes are selectively permeable barriers that surround and compartmentalize cellular components
• What is the role of biological membranes in substance transport?

  Regulates molecule movement
• Biological membranes contain cholesterol and carbohydrates, each contributing to the membrane's structure and function
• Biological membranes consist of a phospholipid bilayer with embedded proteins
• Biological membranes facilitate communication between cells through cell signaling.

  True
• Match the biological membrane component with its function:

  Phospholipids ↔️ Provide a selectively permeable barrier

  Proteins ↔️ Transport molecules and act as receptors

  Cholesterol ↔️ Stabilizes membrane structure
• The fluid mosaic model describes the biological membrane as a rigid, unchanging structure.

  False
• Biological membranes regulate substance transport by controlling the movement of molecules in and out of the cell
• The fluid mosaic model describes the biological membrane as a phospholipid bilayer with embedded proteins, cholesterol, and carbohydrates
• Match the type of membrane protein with its description:

  Integral Proteins ↔️ Span the entire phospholipid bilayer

  Peripheral Proteins ↔️ Attached to the surface of the membrane
• Peripheral proteins are embedded within the phospholipid bilayer.

  False
• Biological membranes consist of a phospholipid bilayer with embedded proteins
• What are the main components of biological membranes?

  Phospholipids, proteins, cholesterol, carbohydrates
• Cholesterol stabilizes the membrane structure and modulates fluidity.


  True
• Carbohydrates in the membrane mediate cell-cell recognition and signaling
• What does the fluid mosaic model describe?

  Biological membrane structure
• What do integral proteins do in the fluid mosaic model?

  Transport, act as receptors
• Match the protein type with its functions:

  Integral Proteins ↔️ Transport molecules across the membrane

  Peripheral Proteins ↔️ Provide structural support to the membrane
• Carbohydrates in the membrane act as markers identifying cell types
• What is the lipid distribution like in the phospholipid bilayer?

  Asymmetric distribution
• What type of lipids are predominantly found in the inner leaflet of the membrane?

  Phosphatidylserine, phosphatidylethanolamine
• How does the fluid mosaic model maintain homeostasis?

  Selective permeability
• Carbohydrates in the membrane mediate cell-cell recognition and communication for immune response.


  True
• Arrange the steps involved in maintaining membrane homeostasis:

  1️⃣ Formation of a selective barrier by phospholipids

  2️⃣ Transport of essential molecules by integral proteins

  3️⃣ Facilitation of cell signaling by peripheral proteins

  4️⃣ Modulation of fluidity by cholesterol
• Carbohydrates attached to proteins or lipids on the outer surface of the membrane mediate cell-cell recognition and signaling
• Arrange the components of the fluid mosaic model in order of their primary function:

  1️⃣ Phospholipid bilayer: Forms a flexible barrier

  2️⃣ Integral proteins: Transport molecules

  3️⃣ Cholesterol: Stabilizes membrane fluidity

  4️⃣ Carbohydrates: Mediate cell recognition
• What is the primary role of phospholipids in biological membranes?

  Form a permeable barrier
• The lateral movement of membrane components allows the membrane to be both fluid and dynamic.


  True
• Integral proteins embedded within the bilayer act as receptors for cell signaling
• What are the two types of carbohydrates commonly found in biological membranes?

  Glycolipids and glycoproteins
• Phospholipids in biological membranes have hydrophilic heads and hydrophobic tails.


  True
• Phospholipids form the bilayer structure with hydrophilic heads and hydrophobic tails
• What are the functions of proteins embedded in the biological membrane?

  Transport, receptors, enzymes, structure
• The components of biological membranes work together to regulate substance transport and compartmentalize cellular processes.


  True
• The phospholipid bilayer forms a flexible barrier regulating substance transport
• The lateral movement of components within the fluid mosaic model enables membrane fluidity.


  True
• What is the primary role of carbohydrates in the membrane?

  Cell recognition
• Carbohydrates are essential for cell communication, immune response, and membrane stability.


  True
• The outer leaflet of the membrane is predominantly composed of phosphatidylcholine and sphingomyelin
• The asymmetric distribution of lipids is crucial for the membrane's selective permeability and fluidity.

  True