1.4a MHS IB Bio

The function of glycoproteins is

• protein production

• cell recognition

• cell replication

• decrease cell fluidity

True/False: Diffusion requires an input of energy.

• True

• False

The rate of diffusion of a substance across a membrane can be maximized by creating a

• large concentration gradient.

• small surface area to volume ratio.

• long length of diffusion pathway.

Diffusion is the movement of _____________ across the membrane, while osmosis is the movement of _____________ across the membrane.

• water; particles

• energy; particles

• particles; water

• particles; energy

True/False: Diffusion, osmosis, and facilitated diffusion are all passive processes because movement is occurring along the concentration gradient.

• True

• False

Generally, when polar molecules are traveling with the concentration gradient, they travel by

• diffusion.

• osmosis.

• facilitated diffusion.

• active transport.

The name of the specialized protein used to transport water is

• aquaporin.

• hydroprotein.

• water pore.

• Protein McProteinface.

The difference between diffusion and facilitated diffusion is

• diffusion occurs directly across the membrane while facilitated diffusion occurs through a protein pore or channel.

• diffusion occurs through a protein pore or channel while facilitated diffusion occurs directly across the membrane .

Why is facilitated diffusion used if water can move by simple diffusion?

• because ATP is needed to drive the process

• to slow down movement of water across the membrane

• to speed up and help regulate water balance

Any molecule traveling against the concentration gradient will move by

• diffusion

• facilitated diffusion

• osmosis

• active transport