Case Study 1
Answers
1.) The PHOSPHOLIPIDS form a lipid bilayer, which acts as a semipermeable membrane. A semipermeable membrane can transit some compounds but not others. “Some things can pass, others cannot!” shows this.
2.) The aquaporin’s allow the H2O molecules to go through the phospholipid bilayer. Aquaporin’s are a transmembrane protein that acts as a channel that allows H2O to pass through. H2O can also enter the cell by diffusion through the membrane but is not as sufficient.
3.) The transmembrane proteins that give transport to these molecules across the membrane are specific for these molecules, or ones very similar to them.
4.) No, because the small compounds enter or leave the cell only through diffusion.
5.) The lungs (respiratory system) and their perfusion of blood (circulatory system) together show physiological gas exchange. All cells that require oxygen supply and carbon dioxide disposal undergo this gas exchange with extracellular environment. Considering the small size of the molecules involved and the large surface area, this is probably the best method.
6.) During the great dehydration the stomach virus somehow raised the tonicity of the extracellular environment, activating the movement of water from the inside the cell to outside to balance solute concentrations across the membrane. The electrolytes in sports drinks are meant to enter into the cell, raise the tonicity relative to the outside. This would cause water retention inside the cell keeping it hydrated, therefore the opposite of dehydration.
7.) Cellular respiration is a long and complicated reaction network but is simplified by a simple combustion reaction. Glucose combines with oxygen to exothermically produce carbon dioxide and waste.
8.) The sodium-potassium pump is a transmembrane protein that transfers sodium and potassium ions against their concentration gradient to establish goal concentrations on either side of the membrane. These concentrations imply a
1.) The PHOSPHOLIPIDS form a lipid bilayer, which acts as a semipermeable membrane. A semipermeable membrane can transit some compounds but not others. “Some things can pass, others cannot!” shows this.
2.) The aquaporin’s allow the H2O molecules to go through the phospholipid bilayer. Aquaporin’s are a transmembrane protein that acts as a channel that allows H2O to pass through. H2O can also enter the cell by diffusion through the membrane but is not as sufficient.
3.) The transmembrane proteins that give transport to these molecules across the membrane are specific for these molecules, or ones very similar to them.
4.) No, because the small compounds enter or leave the cell only through diffusion.
5.) The lungs (respiratory system) and their perfusion of blood (circulatory system) together show physiological gas exchange. All cells that require oxygen supply and carbon dioxide disposal undergo this gas exchange with extracellular environment. Considering the small size of the molecules involved and the large surface area, this is probably the best method.
6.) During the great dehydration the stomach virus somehow raised the tonicity of the extracellular environment, activating the movement of water from the inside the cell to outside to balance solute concentrations across the membrane. The electrolytes in sports drinks are meant to enter into the cell, raise the tonicity relative to the outside. This would cause water retention inside the cell keeping it hydrated, therefore the opposite of dehydration.
7.) Cellular respiration is a long and complicated reaction network but is simplified by a simple combustion reaction. Glucose combines with oxygen to exothermically produce carbon dioxide and waste.
8.) The sodium-potassium pump is a transmembrane protein that transfers sodium and potassium ions against their concentration gradient to establish goal concentrations on either side of the membrane. These concentrations imply a