IB Biology B2.1 Membranes and membrane Transport

Which property makes phospholipids capable of forming a bilayer?

• Complete hydrophobicity

• Amphipathic nature

• Total water solubility

• Ionic bonding

What is the primary function of aquaporins in cell membranes?

• Blocking water movement

• Facilitating water molecule transport

• Generating electrical potential

• Protein synthesis

In the fluid mosaic model, what does 'fluid' specifically refer to?

• Liquid inside the cell

• Membrane proteins moving laterally

• Water passing through membrane

• Constant membrane motion

Which molecules can typically diffuse directly through the plasma membrane?

• Charged ions

• Large polar molecules

• Small non-polar molecules

• Complex proteins

What distinguishes active transport from passive transport?

• Direction of molecular movement

• Molecular size

• Energy requirement

• Membrane protein type

What role do glycoproteins play in cell membranes?

• Structural rigidity

• Cell recognition

• Enzyme catalysis

• Membrane breakdown

Which molecule provides energy for active transport?

• ADP

• ATP

• GTP

• CTP

What makes the phosphate head of a phospholipid hydrophilic?

• Negative charge

• Positive charge

• Neutral configuration

• Hydrophobic interactions

What type of protein spans the entire lipid bilayer?

• Peripheral protein

• Integral protein

• Surface protein

• Transmembrane protein

What prevents protons from moving through aquaporins?

• Negative charge

• Positive charge

• Size restriction

• Hydrophobic interactions