7.3 Cell Transport

The movement of materials across the cell membrane without using cellular energy is called _______________.

• active transport
• sodium-potassium pump
• passive transport
• endocytosis

One of the most important functions of the cell membrane is to keep the cell’s internal conditions relatively constant. It does this by __________________________________.

• regulating the movement of molecules from one side of the membrane to the other side
• undergoing constant death and rebirth
• using protein pumps only
• heating and cooling

Tags

NGSS.HS-LS1-3

The cytoplasm of a cell is a solution of many different substances dissolved in water.

• True
• False

Tags

NGSS.MS-LS1-2

If the substance can cross the cell membrane, its particles will tend to move toward the area where it is less concentrated until it is evenly distributed.  This is called: 

• osmosis
• diffusion
• active transport
• facitated diffusion

When the concentration of the substance on both sides of the cell membrane is the same,____________  is reached.

• pressure
• solution
• diffusion
• equilibrium

Even when equilibrium is reached, particles of a solution will continue to  move across the membrane in both directions.  

• True
• False

Diffusion depends upon______________ .

• random particle movements
• energy from ATP
• movement of air
• all choices are correct

Cell membranes have _________ that act as carriers, or channels, making it easy for certain molecules to cross.

• lipid bilayers
• carbohydrates
• proteins
• ATP

Molecules that cannot directly diffuse across the membrane pass through special protein channels in a process known as _______________.

• diffusion
• endocytosis
• exocytosis
• facilitated diffusion

The inside of a cell’s lipid bilayer is hydrophobic—or “water-hating.” Because of this, water molecules have an easy time passing through the cell membrane.

• True
• False