Homework - Biological Membranes and Membrane Transport

What is the primary composition of biological membranes?

• Nucleic acids and lipids

• Proteins and carbohydrates

• Lipids and proteins

• Carbohydrates and nucleic acids

Which function of biological membranes involves controlling the entry and exit of substances?

• Barrier function

• Signal transduction

• Cell communication

• Transport

What type of proteins span the membrane and can function as channels?

• Transport proteins

• Receptor proteins

• Integral proteins

• Peripheral proteins

What is the role of cholesterol in biological membranes?

• Increases membrane thickness

• Facilitates cell communication

• Acts as a transport protein

• Modulates fluidity and stability

Which model describes membranes as a fluid structure with a mosaic of proteins?

• Phospholipid model

• Static model

• Fluid-mosaic model

• Lipid raft model

What is the primary characteristic of passive transport?

• Occurs along the concentration gradient

• Involves transport proteins

• Moves molecules against their gradient

• Requires energy input

Which type of transport involves the use of ATP to pump ions against their gradients?

• Primary active transport

• Secondary active transport

• Facilitated diffusion

• Simple diffusion

What is the effect of temperature on membrane fluidity?

• Fluidity is constant regardless of temperature

• Higher temperatures decrease fluidity

• Temperature has no effect

• Higher temperatures increase fluidity

What are lipid rafts enriched in?

• Nucleic acids and lipids

• Cholesterol and sphingolipids

• Proteins and carbohydrates

• Phospholipids and proteins

Which of the following is a characteristic of carrier-mediated transport?

• It does not require transport proteins

• It is independent of substrate concentration

• It has a maximum transport rate (Vmax)

• It is always passive