Passive transport into cells is driven by a concentration gradient; a greater concentration of molecules on one side of the membrane. Which direction would oxygen move across a cell membrane if there was a greater concentration of oxygen molecules on the inside of the
membrane?

A. It would continue to concentrate inside the cell.
B. The random diffusion of oxygen would balance and have no net effect.
C. Towards the outside of the cell.
D. None of the above.

The influenza virus cause the flu, but not other diseases. why?

Mouse liver cells were homogenized and the homogenate subjected to equilibrium density-gradient centrifugation with sucrose gradients. fractions obtained from these gradients were assayed for marker molecules (i.e., molecules that are limited to specific organelles). the results of these assays are shown in the figure. the marker molecules have the following functions: cytochrome oxidase is an enzyme involved in the process by which atp is formed in the complete aerobic degradation of glucose or fatty acids; ribosomal rna forms part of the protein-synthesizing ribosomes; catalase catalyzes decomposition of hydrogen peroxide; acid phosphatase hydrolysis monophosphoric esters at acid ph; cytidylyltransferase is involved in phospholipid biosynthesis; and amino acid permease aids in transport of amino acids across membranes. a) name the marker molecule and give the number of the fraction that is most enriched for each of the following cell components: lysosomes; peroxisomes; mitochondria; plasma membrane; rough endoplasmic reticulum; smooth endoplasmic reticulum.

Why reason best illustrates why hershey and chase chose to use viruses in their experiment?