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(a) Identify the most likely mode of transport across the membrane for substance L. Explain how information provided helps deter

Viefleur [7K]

Active transport occurs against the electrochemical gradient. It needs energy to move molecules from the lower concentration side to the higher concentration side. The mode of transport is active transport. 

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There are three main different types of transport across the membrane

Simple diffusion ⇒ Does not need energy to occur
Facilitated transport ⇒ Does not need energy to occur
Active transport ⇒ Needs energy to occur

Active transport is the transport of molecules that move against the electrochemical gradient, so it does need energy to happen.

Molecules move from the lower concentration side to the higher concentration side of the membrane.

Carrier proteins are in charge of active transport. The needed energy might proceed from the ATP molecules or the membrane's electric potential.

In the exposed example, a scientist wants to determine how substance L enters a cells in a culture.

The cells maintain a 120 mM intracellular concentration of substance L.

Varying external concentrations of substance L (10 to 100 mM) in culture medium (Table 1).

Table 1. Rate of entry of substance L into mammalian cells in culture

External concentration of substance(mM) Rate of entry of substance L

10 5%

20 25%

30 45%

40 65%

50 80%

60 90%

70 95%

80 100%

90 100%

100 100%

Now, we need to identify the most likely mode of transport across the membrane for substance L, and explain how information provided helps determine the most likely mode of transport.

We know that the intracellular concentration is 120mM.

As we can see, this concentration exceeds all of the culture media concentrations. Yet, the substance keep moving into the cell.

As the concentration inside the cell is always higher than the concentration outside, we can assume that this is not passive transport because the molecule transport is going against its concentration gradient.

Hence, the remaining option is active transport. And as said before, we can see it because the substance keeps crossing the membrane toward the cell interior despite its concentration being higher in the interior of the cell than in the exterior.

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6 0

3 years ago

How has shark skin been used to inspired materials that slide faster through the water?

sergey [27]

Answer:

Shark skin has been used by many cultures as sandpaper. It's kept shipmates safe in slippery-when-wet conditions. Swimsuits modeled on shark skin are said by Speedo to reduce drag by up to 4 percent. Now, research by two separate groups could lead to synthetic shark skin that would make ships and submarines faster and less expensive to operate.

3 0

3 years ago

How many divisions will it take for a cell to create at least 50 cells?

ella [17]

I think the answer is 2

6 0

3 years ago

object forms when a supergiant runs out of fuel?a red giant a black hole a white dwarf a neutron star

LenKa [72]

ANSWER:

When a supergiant runs out of fuel, the object formed is either a black hole or a neutron star.

EXPLANATION:

Supergiant are very large stars in the galaxy that end their lives very quickly.

When a supergiant star loses its fuel, it blows itself by a supernove explosion.

When supernove explosion happens, the supernova outshines other stars in the galaxy and then slowly faded away leaving a dense object called black hole or neutron star.

This black hole or neutron star is surrounded by a mass of very hot gas and the elements of the supergiant star get scattered into the space.

5 0

3 years ago

Read 2 more answers

Which is NOT part of the cell theory?

atroni [7]

Answer:

B.

Explanation: Hope this helps! ^^

8 0

3 years ago