Cell bio lab5 cell membrane transport

How does coupled transport allow a molecule to be transported against the electrochemical gradient? a) A co-transported molecule travels down an electrochemical gradient in either direction b) It uses energy from light c) Another molecule binds to one side of the transporter driving a conformational change d) It uses energy from ATP

a) A co-transported molecule travels down an electrochemical gradient in either direction

Which of these options is not a mechanism to control the opening and closing of ion channels? a) ATP binding (ATP gated) b) Changes in membrane potential (voltage gated) c) Distortion of the cell membrane (mechanically gated) d) Ligand binding (ligand gated)

a) ATP binding (ATP gated)

These channel and carrier proteins mainly transport molecules passively. Active transport, on the other hand, needs energy. Why does active transport require energy? a) It transports molecules against an electrochemical gradient b) The transporters need to open wider because it transports bigger molecules c) It is faster than passive transport d) It transports molecules that are repelled by the membrane

a) It transports molecules against an electrochemical gradient

Why do we need to label the membrane? a) To visualize the cargo molecules using the fluorescent microscope b) To visualize the cell membrane using the fluorescent microscope c) To visualize the transport proteins using the fluorescent microscope d) To check whether the synthetic cells have a membrane

b) To visualize the cell membrane using the fluorescent microscope

Are the molecules able to cross the membrane? a) No, because there is yellow fluorescence in the cells b) Yes, because there is green fluorescence in the cells c) No, because there is red fluorescence in the cells d) Yes, because there is red fluorescence in the cells

b) Yes, because there is green fluorescence in the cells

The composition of the cell membrane allows some molecules to cross it more easily than others. This is called "relative permeability." Which type of molecule is least able to cross the membrane without transporters? There's a poster in this room that will help you. a) Large uncharged polar molecules b) lons c) Small hydrophobic molecules d) Small uncharged polar molecules

b) lons

Hacker: The cell membrane makes the cell a compartment separate from the extracellular environment. What is the other main function of the cell membrane? a) Compartmentalizing organelles within the cell b) Facilitating the migration of the cell through the body c) Providing a rigid structure that gives the cell shape d) Controlling the transport of substances in and out of the cell

d) Controlling the transport of substances in and out of the cell

Certain scorpions produce a toxin that inhibits the Na+ channel closing. Now that you have identified the role of Na+ channels in nerve cells, can you predict the effect of the scorpion toxin on neuronal function? Remember that you can lower the LabPad to take another look at the wall screen. a) Less Na+ is pumped out of the cell, slowing down return to the resting state b) Hypo-excitability: more Na+ flows into the cell, causing neurons not to fire as readily c) Na+ is toxic to nerves d) Hyper-excitability: more Na+ flows into the cell, causing neurons to fire more readily

d) Hyper-excitability: more Na+ flows into the cell, causing neurons to fire more readily

Clearly, the health of the cells has improved! Compared to the situation when you entered the lab, how has adding the transporter proteins contributed to healthier cells? a) The cells now have different types of lipids b) The cell now lets molecules through non-selectively c) The cell is now a separate compartment d) The cell membrane is now a selective barrier

d) The cell membrane is now a selective barrier

As you can see, an aquaporin has now appeared in the cell membrane. Which types of molecules are transported by aquaporins ? a) All of these molecules b) Bulky molecules c) Charged molecules d) Water

d) Water