Facilitated Diffusion

The model below depicts the movement of several ions and molecules across a cell membrane. For each ion or molecule, the relative concentration on each side of the membrane is shown.

Which of the following statements accurately describes one of the movements shown in the model?

• Cl− is transported out of the cell by active transport.

• Na+ movement into the cell requires ATP hydrolysis.

• Na+ is transported out of the cell by active transport.

• CO2 movement out of the cell requires ATP hydrolysis.

Tags

NGSS.HS-LS1-3

The model below shows how glucose, sodium ions

Na+, and potassium ions K+ move between the intestinal lumen, an epithelial cell, and the blood in the small intestine. The relative concentrations of glucose, Na+, and K+ inside and outside the epithelial cell are indicated.

Based on the model, which of the following movements does not require an input of energy?

• K+ moving out of the blood into an epithelial cell

• Na+ moving out of an epithelial cell into the blood

• glucose moving out of an epithelial cell into the blood

• glucose moving out of the intestinal lumen into an epithelial cell

Which of the following is true regarding the proteins involved in facilitated diffusion?

• Channel and carrier proteins transport materials at different rates.

• Ions such as sodium, potassium, and calcium can move across the membrane through the use of channel proteins.

• Channel and carrier proteins allow molecules to diffuse passively against their concentration gradients.

• Aquaporins are a type of carrier protein.

Which of the following statements about passive transport is true?

• Substances move from areas of high concentration to areas of low concentration.

• Passive transport refers only to the movement of water molecules

• The input of ATP is required in order to facilitate transportation.

• Membrane proteins are always needed in order for it to take place.

ome substances such as sugars, amino acids, and ions move across the cell membrane from an area of high concentration to an area of low concentration using special proteins embedded in the membrane.

Which of the following terms applies to this type of cell transport?

• Facilitated diffusion

• Endocytosis

• Osmosis

• Passive transport

Which of the following describes the function of the sodium-potassium pump?

• After ATP hydrolysis occurs, the phosphate group attaches to the pump before the sodium ions.

• Potassium cannot attach to the pump until the sodium ions detach from the pump.

• Sodium and potassium ions bind to the pump at the same time, and then sodium is released.

• The sodium-potassium pump process begins when potassium attaches to the pump, which hydrolyzes ATP

Tags

NGSS.HS-LS1-3

How can substances be transported across a membrane against their concentration gradient?

• The plasma membrane is fully hydrophobic.

• Some membrane proteins are ATP-dependent carrier molecules.

• The membrane is permeable to these substances

• Some membrane proteins act as channels

Which of the following is an example of active transport?

• Water moving out of the small intestine

• Sodium being reabsorbed in the kidney

• Carbon dioxide exchanging between muscle cells and red blood cells

• Oxygen exchanging between red blood cells and liver cells