Exam 5: Membranes

In individuals with normal blood sugar levels, glucose is reabsorbed into the bloodstream in the kidney by members of the GLUT transporter family, which form an aqueous pore across the membrane through which glucose can move passively.As a result, no glucose is excreted in urine.However, in people with untreated diabetes mellitus, blood sugar levels are high and glucose is often present in the urine.What can explain this occurrence?

Turgor pressure is observed when a plant cells environment is ________________.

Tetrodotoxin is a potent poison, produced by some newts, pufferfish, and blue-ringed octopus that affects sodium transport involved with the voltage gates in neurons.A friend swimming in the Caribbean is pricked by a pufferfish and gets very sick.The most likely action the poison takes is

The actual transport of protons by the proton pump is mediated by a transmembrane protein which undergoes a change in its

A dehydrated runner drinks a lot of water after a race.They rehydrate because

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

In bacteria, fungi, and plants the high internal pressure generated by osmosis is counteracted by the mechanical strength of their

If you were a very thirsty cell, which process would you use to take in some nutrients secreted by one of your neighbors?

Matt is studying how the protein transferrin enters cells.He examines cells that have taken up transferrin, and finds clathrin-coated vesicles.What mechanism was used to take transferrin into the cell?

How can freeze-fracture be used to determine the orientation of a protein in a membrane?

An individual is constipated.They take magnesium salts to help loosen the stool.Why does this work?

The movement of substances to regions of lower concentration is called

Which of the following protein classes are not found as membrane proteins?

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?

If a cell has a normal osmotic pressure of 4500 mmHg and is placed into a solution with an osmotic pressure of 3500 mmHg, what will happen to the cell?

The solution in the container is hypertonic to which egg?

The process often referred to as "cellular eating" is

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

While water continually orients phospholipids into a lipid bilayer, it does not fix the lipids permanently into position.Thus, the bilayer is considered to be _______.

Which type of proteins is embedded in the cell membrane in both active transport and facilitated transport?