Exam 5: Membranes

To test for the presence of starch,iodine can be used.A positive reaction results in a black color.A dialysis bag filled with starch solution and secured on both ends is placed in iodine solution.After 30 minutes the dialysis bag appears black.Based on this information,what most accurately describes what happened?

Cholesterol functions in the plasma membrane to

Cholesterol is a structural component of cell membranes.Amount of cholesterol present can affect membrane stability and permeability.What is the role of cholesterol in a membrane?

One day during the summer you and some friends make ice cream using an electric ice cream maker.To get the ice cream to form,a mixture of salt and ice is packed around the ice cream maker.A few days later you notice a yellow circle of dead grass where the ice cream maker had been placed.You hypothesize that some of the salt and ice mixture spilled onto the grass and ________.

The type of movement that is specific and requires carrier molecules and energy is

Cyclodextrins are a group of compounds capable of removing cholesterol from membranes.The effect most likely to have a large impact on cells as a result of cyclodextrin treatment would be

Facilitated diffusion is an important method for cells in obtaining necessary molecules and removing other ones.Requirements for facilitated diffusion include

The fluid mosaic model proposed by Singer and Nicolson in 1972 explained that

The diagram shows the rate of diffusion into a cell using carrier proteins. McGraw-Hill Education -If Na⁺ levels were depleted in the extracellular fluid,rate of glucose movement would

A scientist performs an experiment in which they create an artificial cell with a selectively permeable membrane through which only water can pass.They inject a 5M solution of glucose into the cell and then place the cell into a beaker of water.After an hour,what effect do you expect to observe?

The rate of diffusion of molecules would be fastest in a cell with an

If ATP production is blocked,decreased transport of material across a membrane occurs.Which type of transport is affected? Choose all that apply.

Incubation of cells at 20°C blocks the release of proteins from the trans-Golgi.Under such conditions,you would expect to see

A novice gardener notices that many plants in his garden look wilted.What osmotic solution would you suggest the novice gardener use to best return the plants to full health?

If a cell has the same concentration of dissolved molecules as its outside environment,the cell's condition is referred to as being

A dehydrated runner drinks a lot of water after a race.He or she rehydrates because

The diagram shows the rate of diffusion into a cell using carrier proteins. McGraw-Hill Education -The rate of diffusion will increase as

Membrane fluidity is affected by

The fluid nature of the membranes is attributed to a lateral movement of

A phospholipid molecule has a polar and a nonpolar end.Because of this,water molecules form