Which of the following transport mechanisms utilizes energy? a) osmosis b) diffusion facilitated difusion d) endocytosis
Endocytosis is an active transport, a biological process in which molecules from outside the cell (proteins for example) are passed through the cell membrane and put into the cell. This process requires energy.
The other transport mechanisms, osmosis, diffusion and facilitated diffusion are processes that do not utilize energy.
Rocks do not have DNA
RNA has Uracil instead of adenine which is found in DNA
Active transport requires additional energy from ATP
The correct answer is B) Endocytosis.
Endocytosis can be defined as the uptake of large molecules by a cell that requires energy of the cell. Therefore, it is an energy consuming process.
Example- Ingestion of bacteria by macrophages is an energy consumig process and described under endocytosis.
On the other hand, osmosis ( diffusion of water), diffusion, and facilitated diffusion ( requiring carrier proteins) are all passive phenomenon that do not require energy.
The correct answer is option D
SECONDARY ACTIVE COUNTER-TRANSPORT
Explanation: Secondary active transport is a type of transport that involves molecules across the cell membrane utilizing or making use of energy in other forms than Adenosine Triphosphate (ATP).
The energy that is being made use of comes from the electrochemical gradient created by pumping ions out of the cell. This can be either via antiport or symport.
Antiport or Counter-transport means that 2 different molecules or ions are being transported at the same time but opposite directions. One of the species is allowed to flow from high concentration to a lower concentration (often Sodium) while the other species is transported simultaneously to the other side.
Example is Na+-H+ counter-transport, the example and advantage of this transporter is clearly seen in the proximal tubules of the kidneys. The mechanism for concentrating H+ is not nearly as powerful as Primary active transport, however it can transport extremely large numbers and thus making it a key in H+ homeostasis in the body.
ATP is usually used in processes and biochemical reactions in the body that would not occur spontaneously hence require energy to proceed them forward.
One such process is the transport of molecules against the concentration gradient. This is akin to climbing a hill. The channels that carry the molecule against concentration gradient require energy in carrying the molecule from the low concentration outside the cell to high concentration inside the cell. This is called active transport. Facilitated diffusion use membrane channels too, but no ATP energy is consumed because the molecules are moving down concentration gradient.
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D. secondary active counter-transport
The protien transporter on the T-tubule is a secondary active counter transporter.
As the Ca2+ ions are pumped out of the cell and the Na+ ions are entered in the cell by a transporter which is using the energy derived from the sodium gradient to fuel the exchange. Hence thisis secondary active counter-transport.
Secondary active counter transport.
Secondary active counter transport: It is an active transport from the biological membrane that plays a role in the movement of a couple of protein ions down. The movement of another ions uphills sides against an electrochemical gradient. Thus the energy will be stored in the ions. This energy is used for another solution against a electrochemical energy or gradient energy.
It is of two types
Co-transport Exchange transport.