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2 years ago

When nerve cells establish a voltage across their

Biology

1 answer:

svp [43]2 years ago

6 0

Answer:

The answers are:

The sodium potassium pump transports 2 potassium ions (K+) inside the cell and 3 sodium ions (Na+) outside the cell by the hydrolysis of ATP into ADP. The break down of ATP occurs because it generates an inorganic phosphate. This inorganic phosphate is crucial for the phosphorylation of the Na+/K+ pump to activate it.
The sodium potassium pump cannot be classed as co-transporter because the Na+/K+ pump transports both the ions against the concentration gradient whereas, a cotransporter transports one substance down the concentration gradient and the other against.
An regulated proton transport would never develop a proton gradient. This would hamper processes like the synthesis of ATP and sucrose co-transport that require a H+ gradient.

Explanation:

Working of Sodium/Potassium Pump (NA+/K+) Pump:

The sodium potassium pump is a transmembrane transport channel that actively transports Na+ and K+ ions in and out of the cell to develop a concentration gradient.
The NA+/K+ pump contains the enzyme Na+/K+ ATPase that hydrolyses (breaks down in presence of water) ATP into ADP and inorganic phosphate (Pi).
The inorganic phosphate phosphorylates the transport proteins causing a change in conformation.
This energy (in the form of inorganic phosphate) is used to actively transport 2 potassium ions inside the cell and 3 sodium ions outside. This maintains a concentration gradient of the two ions at rest. This unbalanced charge maintains the resting membrane potential on the membrane of the neuron.
A reversal of the membrane potential i.e. more K+ outside and more Na+ inside the cell generates an action potential on the membrane.
This action potential is the nerve impulse that travels throughout the nervous system.

Co-transporter:

A co-transporter is a sub-class of transport channels that transports two substances at the same time, one down its concentration gradient and the other against.
Symporters and uniporters are types of co-transporters.
A Na+/K+ pump cannot be classed as a co-transporter as it transports both sodium and potassium ions against their concentration gradient by the break down of ATP.

Proton (H+) Gradient:

A proton gradient is essential for the production of ATP by the process of cellular respiration.
The enzyme responsible for ATP generation, ATP synthase is a molecular motor that couples the proton gradient generated by proton transporters and the energy produced by the break down of ATP into ADP to produce more ATP.

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these types of cells are found in the reproductive organs and are called [germ/ somatic ]cells

Leto [7]

Answer:

Germ

Explanation:

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3 years ago

(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

PLEASE HELP ME!!

Kaylis [27]

It would be the first one m.

3 0

2 years ago

Read 2 more answers

To correctly document the pulse that is palpated behind the knee, the healthcare practitioner would document this as the pulse o

Roman55 [17]

To correctly document the pulse that is palpated behind the knee, the healthcare practitioner would document this as the pulse of the popliteal artery. The popliteal artery extends from the femoral artery and is located in the knee, at the back of the leg.

5 0

3 years ago

Proteins are one of the three macronutrients found in the diet and important structural molecule organisms. Proteins help provid

xxTIMURxx [149]

Answer:

The human body is able to synthesize them: proteins, fats

Contains nitrogen in the amine group : proteins

Made according to instructions from DNA: proteins

Explanation:

The cells of the human body synthesize proteins from the transcription and translation processes.

Fats and carbohidrates are ingested in the diet and metabolized by the body. However some types of fat such as cholesterol is synthesized by the human body. Same as phospholipids that are part of the membranes.

Proteins are formed by hydrogen, oxygen, nitrogen and carbon. Amino acids are characterized for owning a carboxyl group (- COOH) and an amino group (-NH2)

3 0

3 years ago