Molecular Transport

What is diffusion?

• Process by which molecules move from areas of lower concentration to areas of Higher concentration

• Process by which molecules move from areas of lower concentration to areas of higher concentration with the help of a membrane.

• Process by which molecules move from areas of higher concentration to areas of lower concentration.

• Process by which molecules move from areas of higher concentration to areas of lower concentration with the help of a membrane

Why is osmosis a form of diffusion?

• Osmosis is the diffusion of water across a membrane

• Osmosis moves from areas of lower concentration to higher concentrations

• Osmosis use a membrane to transport water

Molecules that are soluble in lipids tend to move across cell membranes more quickly than those that are not. Based on this information, what could you conclude about the structure of the cell membrante?

• That the cell membrane is made of lipids

• That the cell membrane is selectively permeable

• That the cell membrane has a hydrophobic tail and hydrophilic head.

• All answers are right

The red blood cell contains a higher concentration of K+ ions than does the liquid that surrounds it. Are k+ ions most likely to be move across the membrane by facilitated diffusion or active transport?

• Facilitated diffusion

• Active Transport

Which is an example of active transport?

• Diffusion

• Osmosis

• Endocytosis

• Facilitated diffusion

Facilitated diffusion is a form of active transport

• True

• False

The movement of water through the membrane in order to reach equilibrium is ________

• osmosis
• facilitated diffusion
• concentration gradient
• active transport

__________ uses ATP to power protein channels moving molecules into a hypertonic solution. 

• active transport
• facilitated diffusion
• passive diffusion
• ATP moleculase

When a membrane only allows certain molecules through, it is called ______

• selectively permeable
• passive diffusion
• equilibrated
• singly permeable

Which of the following molecular movements is due to osmosis or diffusion?

• Cells of the pancreas secrete insulin into the bloodstream.

• A plant cell is placed in concentrated NaCl solution and water moves out of the cell.

• Sodium potassium pump pumps 3 Na⁺ ions out of the cell for every 2 K⁺ ions it moves in.