Most meteorites contain iron and nickel and are therefore

A) Compare and contrast diffusion, passive transport (diffusion & facilitated), primary active transport and secondary activ

zheka24 [161]

Answer:

Passive transport: It does not need any energy to occur. Happens in favor of an electrochemical gradient. Simple diffusion and facilitated diffusion are kinds of passive transport.

Simple diffusion: molecules freely moves through the membrane.

Facilitated diffusion: molecules are carried through the membrane by channel proteins or carrier proteins.

Active transport needs energy, which can be taken from the ATP molecule (Primary active transport) or from a membrane electrical potential (Secondary active transport).

Explanation:

Diffusion: This is a pathway for some small polar hydrophilic molecules that can freely move through the membrane. Membrane´s permeability depends on the size of the molecule, the bigger the molecule is, the less capacity to cross the membrane it has. Diffusion is a very slow process and to be efficient requires short distances and pronounced concentration gradients. An example of diffusion is osmosis where water is the transported molecule.

Facilitated diffusion: Refers to the transport of hydrophilic molecules that are not able to freely cross the membrane. Channel protein and many carrier proteins are in charge of this passive transport. If uncharged molecules need to be carried this process depends on concentration gradients and molecules are transported from a higher concentration side to a lower concentration side. If ions need to be transported this process depends on an electrochemical gradient. The glucose is an example of a hydrophilic protein that gets into the cell by facilitated diffusion.

Simple diffusion and facilitated diffusion are passive transport processes because the cell does not need any energy to make it happen.

Active transport occurs against the electrochemical gradient, so it does need energy to happen. Molecules go from a high concentration side to a lower concentration side. This process is always in charge of carrier proteins. In primary active transport the energy needed comes from the ATP molecule. An example of primary active transport is the Na-K bomb. In secondary active transport, the energy comes from the membrane electric potential. Examples of secondary active transport are the carriage of Na, K, Mg metallic ions.

7 0

3 years ago

Lincoln is a 27-year-old man who has been experiencing strange medical symptoms over the past year. He knows something is wrong,

Amanda [17]

I'm not sure, but it could possibly be diabetes

7 0

3 years ago

A/An ___ is an acute, life-threatening condition with hemorrhage into a vessel wall resulting from a longitudinal tearing of the

pogonyaev

Answer:

Aortic dissection

Explanation:

7 0

2 years ago

position vs time for two cars which statements best describe the motion of car a and car b check all that apply

jekas [21]

Answer:

Option 1, 2, 5

Explanation:

Options for the question

car a and car b are both moving toward the origin.
car a and car b are moving in opposite directions.
car a is moving faster than car b.
car a and car b started at the same location.
car a and car b pass each other at the crossover point on the graph. time (s)

Solution -

The motion of any object is represented by position-time In such graphs the position of an object is fixed for any starting point on the y-axis and time on the x-axis.

The slope of such curves determine the velocity of the object at all its position within the graph. The steeper the slope is, the faster the the object is moving.

Hence, the following statements are correct

Option 1, 2, 5

3 0

3 years ago

Genetic drift is change in the allele frequency of a population due to

svp [43]

Answer:

Genetic drift is change in allele frequencies in a population from generation to generation that occurs due to chance events. To be more exact, genetic drift is change due to "sampling error" in selecting the alleles for the next generation from the gene pool of the current generation.Explanation:

7 0

3 years ago