Starch molecules are too large to pass through the

(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

Amylase increases the rate at which starch is broken down into glucose. What kind of molecule is amylase?

Aleksandr [31]

I think it's B. Enzymes

6 0

3 years ago

Read 2 more answers

Biology pls help!!!!! Will give brainlest

myrzilka [38]

Answer:

Organism with AABBCCDD genotype will produce only one type of gamete, ABCD and the organism having the genotype AaBbCcDd will produce 16 types of gametes.

This is a percentage of 3.1%

Explanation:

8 0

2 years ago

Abiotic factors in the environment are all _________. A. Easily measured B. Living C. The same as the dead things D. Non living

Ede4ka [16]

Answer:

the answer is d. non living

8 0

3 years ago

Which molecule prevents a muscle contraction from occurring when the muscle is at rest?

AysviL [449]

Troponin-tropomyosin molecules prevents a muscle contraction from occurring when the muscle is at rest.

<h3>What is muscle contraction?</h3>

The activation of tension-producing regions within muscle cells results in muscular contraction. Because muscle tension can be created without changes in muscle length, such as when holding something heavy in the same position, muscle contraction does not always imply muscle shortening in physiology. Muscle relaxation, or the return of the muscular fibers to their low tension-generating state, occurs after a muscle contraction has finished.

Both length and tension can be used to characterize muscle contractions. If the muscle tension varies but the muscle length doesn't, the muscle contraction is said to be isometric. A muscle contraction is isotonic, however, if the tension in the muscle remains constant during the contraction.

To learn more about muscle contraction with the help of given link:

brainly.com/question/10115123

#SPJ4

5 0

1 year ago