Help me please i need to pass

(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. 

-------------------------------------------------

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.

-------------------------------------------------------------

6 0

3 years ago

What characteristic do protozoa and fungi share?

Nadusha1986 [10]

Answer:

<h2>letter A</h2>

Explanation:Whittaker placed bacteria in their own kingdom, Monera, because of fundamental organizational differences between prokaryotic bacterial cells, which lack membrane-enclosed nuclei and organelles , and the eukaryotic cells of other organisms that possess internal membranes. Plantae, Fungi, and Animalia consist of complex, multicellular eukaryotic organisms that differ from each other in details of cell structure and in how they secure and process energy. Protista is a collection of single-celled eukaryotic organisms and simple multicellular forms, some animal-like, some plantlike.

<h2>letter b</h2>

Molecular evidence, particularly from ribosomal ribonucleic acid (RNA), suggests that the five-kingdom scheme is also too simple. Some biologists believe that Protista should be partitioned into three or more kingdoms. Similarly, kingdom Monera contains two very biochemically distinct groups of prokaryotes: archaebacteria, and eubacteria. A proposed system acknowledges this ancient evolutionary split by creating a higher level of classification, domain, above kingdom. This system distinguishes three domains: Archaea, Eubacteria, and Eukarya (containing protists, plants, fungi, and animals).

7 0

3 years ago

Which fruit has one seed with grooves on it?

Ronch [10]

The answer is c. peach or nectarine

A peach has only one seed. Its seeds have grooves around it.

Banana has many seeds although very small to notice. A cherry has one or two seeds but it does not have grooves on it. An orange seed has grooves on it but there are a lot of them in one fruit.

6 0

3 years ago

Name the subunits that make up each of the macromolecules

Eddi Din [679]

The sub units that make up Macromolecules are proteins, lipids, nucleic acids, and carbohydrates.

3 0

3 years ago

Read 2 more answers

Where does the water in lakes come from? Select the three correct answers.

baherus [9]

D: Surface-water runoff from rain

7 0

3 years ago

Read 2 more answers