1.1.5 Movement Across Cell Membranes

• What is the function of the phospholipid bilayer in the cell membrane?

  Forms basic structure
• Which type of protein transports larger molecules like sugars across the cell membrane?

  Carrier proteins
• Active transport requires ATP to move substances against their concentration gradient.

  True
• Osmosis requires a semi-permeable membrane for water to move across.


  True
• Facilitated diffusion is selective for specific substances.


  True
• Both sodium-potassium pump and vesicular transport require ATP.


  True
• Active transport is essential for regulating the cell's internal environment.


  True
• Does passive transport require ATP?

  No
• What is the driving force behind diffusion?

  Concentration gradient
• What energy source is required for active transport?

  ATP
• What is the role of selective permeability in the cell membrane?

  Regulate substance concentrations
• The cell membrane is a barrier that surrounds the cell, controlling what enters and exits
• Channel proteins in the cell membrane allow specific substances to pass through their pores
• The cell membrane is selectively permeable, allowing all substances to pass through freely.

  False
• Which process is an example of active transport?

  Vesicular transport
• What type of substance is moved during osmosis?

  Water
• What is the primary function of the sodium-potassium pump?

  Maintains ion balance
• What is active transport?

  Movement against concentration gradient
• What is the cell membrane composed of?

  Phospholipid bilayer
• Substances in passive transport move with the concentration gradient
• Osmosis is the movement of water across a semi-permeable membrane
• Steps of the sodium-potassium pump

  1️⃣ ATP binds to the pump

  2️⃣ Shape changes to release Na+

  3️⃣ K+ binds, shape reverts, releasing K+ inside
• The movement of substances across the cell membrane is crucial for maintaining the cell's internal environment
• Phospholipid molecules have a hydrophilic head and hydrophobic tail.


  True
• Passive transport moves substances across the membrane without using energy
• Diffusion is the movement of particles from an area of high concentration to an area of low concentration
• Facilitated diffusion uses channel proteins to help specific substances cross the membrane
• Vesicular transport uses membrane-bound vesicles to transport larger molecules
• The sodium-potassium pump uses ATP to pump sodium ions out of the cell and potassium ions into
• The phospholipid molecules in the cell membrane arrange with hydrophilic heads facing outwards and hydrophobic tails facing inwards
• Active transport moves substances against their concentration gradient.


  True
• Match the feature with the correct transport process:

  Diffusion ↔️ Moves particles from high to low concentration

  Osmosis ↔️ Moves water across a semi-permeable membrane
• Passive transport ensures precise substance regulation within the cell.

  False