2.5.2 Transport mechanisms

• What are transport mechanisms in biology?

  Movement across biological membranes
• Passive transport requires energy in the form of ATP.

  False
• Active transport moves molecules against their concentration gradient.


  True
• What type of active transport engulfs extracellular substances by forming vesicles?

  Endocytosis
• Passive transport requires energy in the form of ATP.

  False
• Simple diffusion is the net movement of molecules from an area of high concentration to an area of low concentration.
• What type of molecules are typically transported by simple diffusion?

  Small, nonpolar molecules
• Passive transport does not require energy
• Arrange the following transport types under passive and active transport categories:

  1️⃣ Diffusion (Passive)

  2️⃣ Facilitated Diffusion (Passive)

  3️⃣ Osmosis (Passive)

  4️⃣ Active Transport (Active)

  5️⃣ Co-transport (Active)

  6️⃣ Endocytosis (Active)

  7️⃣ Exocytosis (Active)
• What is simple diffusion?

  Movement from high to low concentration
• Match the factor with its effect on the rate of simple diffusion:

  Temperature ↔️ Higher temperature increases rate

  Concentration Gradient ↔️ Steeper gradient increases rate

  Molecular Weight ↔️ Smaller molecules diffuse faster

  Membrane Surface Area ↔️ Larger area increases diffusion
• Carrier proteins have high binding specificity
• Osmosis involves the movement of water molecules across a semi-permeable membrane.

  True
• Osmosis allows water to move against its concentration gradient without energy expenditure.


  True
• Which type of molecules can be transported by simple diffusion?

  Small, nonpolar molecules
• How does temperature affect the rate of simple diffusion?

  Higher temperature increases it
• Smaller molecules diffuse faster than larger molecules.

  True
• Carrier proteins change shape to transport molecules, while channel proteins form pores
• What role does osmosis play in plant cells?

  Maintains turgor pressure
• Active transport moves molecules against their concentration gradient.


  True
• What is the key difference between active and passive transport?

  Energy requirement
• In phagocytosis, the cell engulfs large particles
• Passive transport moves substances against their concentration gradient.

  False
• Transport mechanisms fall under two main categories: passive transport and active transport.
• What energy source does active transport require?

  ATP
• Match the type of active transport with its description:

  Active Transport ↔️ Uses carrier proteins and ATP

  Co-transport ↔️ Moves two molecules together

  Endocytosis ↔️ Captures extracellular substances in vesicles
• Exocytosis releases intracellular substances by fusing vesicles with the membrane.
• What energy source is required for active transport to move molecules against their concentration gradient?

  ATP
• Simple diffusion requires the use of carrier proteins.

  False
• What are transport mechanisms in biology?

  Movement across biological membranes
• Active transport requires ATP energy to move molecules against their concentration gradient.


  True
• In passive transport, molecules move down their concentration gradient without energy input.


  True
• Simple diffusion requires no energy
• Facilitated diffusion requires energy input to move molecules across the membrane.

  False
• Arrange the steps involved in facilitated diffusion using carrier proteins:

  1️⃣ Carrier protein binds to the molecule

  2️⃣ Protein changes shape

  3️⃣ Molecule is released on the other side

  4️⃣ Protein returns to its original shape
• What is the driving force behind osmosis?

  Difference in water potential
• Passive transport requires no ATP
• Facilitated diffusion uses carrier proteins or channel proteins to aid molecule movement.

  True
• A steeper concentration gradient increases the rate of diffusion
• What type of transport is facilitated diffusion?

  Passive transport