The parasite Trypanosoma brucei, which causes sleeping sickness, uses proline as an energy sourceduring one stage of its life cycle. The properties of this proline-specific transporter wereinvestigated in a series of experiments. L-hydroxyproline inhibited the transporter. D-proline didnot inhibit the transporter. Na*, K*, and pH changes did not affect the transporter. Which of thefollowing is a reasonable hypothesis based on this data?The proline transporter is a Na+-K+ ion pump.The proline transporter cleaves amide bonds.The proline transporter is stereospecific.The proline transporter requires metal-ion catalysis.The proline transporter has an essential ionizable histidine residue,

A transport mechanism that works to facilitate the movement of substances in and out of the cell…

Answered: The parasite Trypanosoma brucei, which…

Biochemistry

9th Edition

ISBN:9781319114671

Author:Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.

Publisher:Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.

Chapter1: Biochemistry: An Evolving Science

Section: Chapter Questions

Problem 1P

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Similar questions

During an investigation on membrane transport, a researcher exposed bacterial cells to different concentrations of two different solutes: A and B. The rate of transport of each solute into cells isrepresented in the graphSolute ASolute BSolute ConcentrationWhich of the following best explains the greater rate of transport for solute A than for solute B at higher solute concentrations?A Solute A is being transported by simple diffusion, which does not rely on membrane proteins to control the rate of transportSolute A is being transported by active transport, which uses ATP and has higher rates of transport than passive transportSolute A is being transported by facilitated diffusion, which uses membrane proteins to increase the rate of transportRate of Transport
Here is a chloride cell in the gill epithelium of a fish. For reference, NKA = Na+/K+ ATPaseNKCC = Na+/K+/Cl- cotransporter. CFTR allows for movement of Cl- from inside the cell out into the water down a concentration gradient. Which of the following would be true of CFTR? A. It is a primary active transporter. B. It is a symporter. C. It is a secondary active transporter. D. It is a channel that allows for facilitated diffusion.
"Transporters saturate at high concentrations of the transported molecule when all their binding sites are occupied; channels, on the other hand, do not bind the ions they transport and thus the flux of ions through a channel does not saturate." is true or false.
the sodium channel exchanger NCX transports sodium into and calcium out of cardiac muscle cells. Describe why this itransporter is classified as secondary active transport?
Cells of Escherichia coli transport lactose via lac permease,glucose via the phosphotransferase system, and maltose viaan ABC-type transporter. For each of these sugars describe:(1) the components of the transport system and (2) the sourceof energy that drives the transport event.
Uniporters and ion channels support facilitated transport across cellular membranes. Although both are examples of facilitated transport, the rates of ion movement via an ion channel are roughly 104 - to 105 -fold faster than the rates of molecule movement via a uniporter. What key mechanisticdifference results in this large difference in transport rate?What contribution to free energy (ΔG) determines the direction of transport?
Which statements are true? Explain why or why not.1 Transport by transporters can be either active orpassive, whereas transport by channels is always passive.2 Transporters saturate at high concentrations ofthe transported molecule when all their binding sites areoccupied; channels, on the other hand, do not bind theions they transport and thus the flux of ions through achannel does not saturate.3 The membrane potential arises from movementsof charge that leave ion concentrations practically unaf-fected, causing only a very slight discrepancy in the num-ber of positive and negative ions on the two sides of themembrane.
only in cell biology...... Which ones of the following are examples of passive transporters? i. Na+-K+ pump ii. Glucose Transporter iii. Ca++ Pump iv. Na+ Channel v. H+ Pump
Uniporters and ion channels support facilitated transport across cellular membranes. Although both are examples of facilitated transport, the rates of ion movement via an ion channel are roughly 104- to 105-fold faster than the rates of molecule movement via a uniporter. What key mechanistic difference results in this large difference in transport rate? What contribution to free energy (ΔG) determines the direction of transport?
Inhibition of the Na,K-ATPase might reasonably result in which of the following: a.) gradual cellular accumulation of K+ b.) gradual decrease in cytoplasmic Na+ c.) cell shrinkage d.) hyperpolarization of the membrane potential e.) reduced activity of many secondary active transporters
The cell membranes of mammalian red blood cells are permeableto urea. If red blood cells are dropped into a solution of urea thatis identical in osmotic pressure (isosmotic) to the cytoplasm ofthe cells, although the cells do not swell and burst as quickly aswhen they are dropped simply into pure water, they eventuallyswell and burst. Explain. Also discuss how you would designa solution into which red cells could be placed without everswelling. (Hint: Think about whether urea will stay on theoutside of the cells and the implications for osmotic pressures.)
Below find the structures for ibogaine and cocaine. Ibogaine and cocaine inhibit the dopamine active transporter (DAT). This transporter is a secondary active transporter, and depends on the primary active transporter Na+/K+ ATPase. Ibogaine had a Kι = 2 μM, and cocaine a Kι = 0.64 μM respectively. (a) Define secondary active transport. (b) Is ibogaine an effective treatment for cocaine based on DAT binding?

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