Cell membrane transport Revision PT1

In what way do the membranes of an eukaryotic cell vary?

• some membranes have hydrophobic surfaces exposed to the cytoplasm, while others have hydrophilic surfaces facing the cytoplasm.

• certain proteins are unique to each membrane

• only certain membranes are constructed from amphipathic molecules

• phospholipids are found only in certain membranes

According to the fluid mosaic model of membrane structure, proteins of the membrane are mostly

• confined to the hydrophobic core of the membrane

• embedded in a lipid bilayer

• randomly oriented in the membrane, with no fixed inside-outside polarity

• free to depart from the fluid membrane and dissolve in the surrounding solution

Which of the following factors would tend to increase membrane fluidity?

• a greater proportion of unsaturated phospholipids

• a greater proportion of relatively large glycolipids compared with lipids having smaller molecular masses

• a relatively high protein content in the membrane

• a greater proportion of saturated phospholipids

What type of transport requires energy?

• Diffusion

• Osmosis

• Active transport

• Facilitated diffusion

Which type of transport is responsible for moving large particles into a cell?

• Passive transport

• Osmosis

• Active transport

• Diffusion

What type of transport involves the movement of water across a semipermeable membrane?

• Diffusion

• Osmosis

• Endocytosis

• Exocytosis

Which term describes the movement of molecules from an area of high concentration to an area of low concentration?

• Endocytosis

• Exocytosis

• Diffusion

• Active transport

What is the term for the process by which large molecules are engulfed by the cell membrane and brought into the cell?

• Diffusion

• Osmosis

• Endocytosis

• Exocytosis

Which term describes the process by which large particles exit the cell?

• Diffusion

• Osmosis

• Endocytosis

• Exocytosis

What is the name of the temporary organelle formed during endocytosis?

• Nucleus

• Mitochondria

• Vesicle

• Chloroplast