Transport mechanisms

• What is the primary structure of the cell membrane?

  Phospholipid bilayer
• What are the two layers of the phospholipid bilayer composed of?

  Back to back phospholipids
• What components make up the cell membrane?

  Intrinsic & extrinsic proteins and cholesterol
• What are the main components of a phospholipid?

  Glycerol molecule, phosphate group, and fatty acids
• What charge does the phospholipid head carry?

  Positive charge
• How does the phospholipid head interact with water?

  It is hydrophilic and attracted to water
• What charge do the phospholipid tails have?

  Negative charge
• How do the phospholipid tails interact with water?

  They are hydrophobic and repel water
• What is the function of intrinsic proteins in the cell membrane?

  They span the whole length of the membrane
• What does a selectively permeable membrane allow?

  Specific substances to pass through
• What are extrinsic proteins associated with?

  Carbohydrate branches for cell signaling
• What are glycoproteins?

  Proteins associated with carbohydrate branches
• What role does cholesterol play in the cell membrane?

  Adds structural stability
• What is facilitated diffusion?

  Movement of large or charged molecules across the membrane
• What is required for facilitated diffusion?

  Intrinsic proteins as carrier proteins
• What is the direction of movement in facilitated diffusion?

  From high concentration to low concentration
• Is energy required for facilitated diffusion?

  No energy is required
• What is active transport?

  Movement from low concentration to high concentration
• What is required for active transport?

  Energy in the form of ATP
• What happens to ATP during active transport?

  ATP converts to ADP
• What does active transport produce?

  Energy to push molecules through the membrane
• What factors affect cell membranes?

  Temperature and solvents
• How does temperature affect the phospholipid bilayer?

  Increased temperature makes it more fluid
• What effect do solvents like alcohol have on the membrane?

  They disrupt membrane structure and increase permeability
• How do solvents affect proteins in the membrane?

  They denature proteins by disrupting bonds