High School Biological Transmembrane Transport 50, High School Biological Transmembrane Transport

Because cell membrane components contain lipids, and glycerol is a soluble lipid of lipids, glycerol can diffuse freely into cells. Calcium ions, on the other hand, are charged and need to be transported against the concentration, which can only be actively transported.

Free diffusion: A simple mode of transport from the side with a high concentration to the side with a low concentration. The diffusion of glycerol is free and does not require a vehicle and ATP to enter the cell along the concentration gradient.

It can also be said that the substances are similar and have compatibility, and the glycerol and phospholipids in the cell membrane are both non-polar structures that are miscible with each other, so they can enter the cell and diffuse freely.

Active transport refers to the process by which substances are transported into or out of the cell membrane under the action of ATP with the assistance of a carrier against the concentration gradient. Plasma Na+, K+, and Ca2+ do not freely pass through the phospholipid bilayer, and they are transported from the low-concentration side to the high-concentration side, inversely on the concentration gradient, with the assistance of carrier proteins, and at the same time need to consume the energy released by intracellular chemical reactions.

Glycerol is because of its similar solubility, so it does not need to be actively transported, while substances such as calcium ions need to be actively transported.

The main component of the membrane is phospholipids, and glycerol is also a lipid, so it does not need to be actively transported because of its similar compatibility.

Ca+ is an important trace element, regardless of the external concentration, the cell always needs it, so it should be actively transported.

The lipophilic part of the middle part of the phospholipid bilayer does not allow the passage of charged substances.

Active transport, passive transport, which also depends mainly on the concentration difference between the inside and outside of the membrane.

One is ionic and the other is lipid on the cell membrane.

Is the membrane made up of lipids? What is glycerol? Think about it, do you understand?

In high school organisms, not all ions are transported across membranes that require energy. Free diffusion and assisted diffusion do not consume energy, and active transport consumes ATP.

Active transport involves the input and output of substances to cells and organelles (membrane structures) and is capable of inverting concentration gradients or electrochemical gradients.

Active transport refers to the process by which substances are transported into or out of the cell membrane under the action of carrier proteins and energy against the concentration gradient.

Plasma Na+, K+, and Ca2+ do not move freely through the phospholipid bilayer, and they are transported from the low-concentration side to the high-concentration side, with the assistance of carrier proteins, and at the same time, they also need to consume the energy released by intracellular chemical reactions, which is called active transport. It can be divided into primary active transportation and secondary active transportation.

Yes, because the transport of ions is all active transport. The transport of moisture is not required because it is free to diffuse.

Biofilm ion channels are pathways for the passive transport of various inorganic ions across membranes. There are two ways of transmembrane transport of inorganic ions by biofilms: passive transport (cision concentration gradient) and active transport (inverse ion concentration gradient). The pathway of passive transport is called the ion channel, and the actively transported ionophore is called the ion pump.

The permeability of biofilm to ions is closely related to a variety of life processes, free diffusion and assisted diffusion do not consume energy, and active transport consumes ATP

Energy is not necessarily required for ion transport across membranes.

In most cases, the transmembrane transport of ions is active and requires the assistance of a carrier to consume ATP, which is generally inverse to the concentration gradient (and also para-concentration gradient).

However, ions transported through ion channels (e.g., sodium influx when nerve cells generate action potentials) do not require energy, but rather are passively transported along the concentration gradient (see ion channels in the figure above).

Active transport, passive transport, assisted diffusion, active transport requires energy.

Energy is required for active transport.

free diffusion of steroids and fatty acids; protein endocytosis; Amino acids are actively transported.

Free diffusion Assisted diffusion: High concentration Low concentration.

Active transport: Low concentration High concentration (high concentration low concentration in special cases) free diffusion does not require a carrier, assisted diffusion and active transport requires a carrier (carrier protein). Free diffusion and assisted diffusion do not consume energy, and active transport consumes ATP.

Animals are generally actively transported, plants are generally polar transported, and steroids and fatty acids are freely diffused.

free diffusion of steroids and fatty acids;

protein endocytosis;

Amino acids are actively transported.

PS: Hormones are divided into.

The first category is steroids, such as adrenocorticosteroids (cortisol, aldosterone, etc.), sex hormones (estrogen, progesterone, androgens, etc.).

The second category is amino acid derivatives, including thyroxine, adrenal medullary hormone, pineal hormone, etc.

The structure of the third type of hormones is peptides and proteins, such as thalamic hormones, pituitary hormones, gastrointestinal hormones, insulin, calcitonin, etc.

The fourth category is fatty acid derivatives, such as prostaglandins.

Both assisted diffusion and active transport in the transmembrane transport of substances are related to the fluidity of the cell membrane.

Analysis: Transmembrane transport can be divided into passive transport and active transport, of which passive transport can be divided into free diffusion and assisted diffusion.

Free diffusion does not require a carrier, but both assisted diffusion and active transport require the participation of carrier proteins in the cell membrane, and therefore the fluidity of the cell membrane, that is, the selective permeability of the cell membrane.

Therefore, the selective permeability of the cell membrane is also a sign of cell activity, or that only the active cell membrane can be actively transported and assisted in diffusion, and the inactive cell membrane can only be freely diffused.

Energy is not necessarily required for ion transport across membranes.

In most cases, ions are transported across membranes by active transport.

The assistance of the vector is required to consume ATP, which is generally an inverse concentration gradient (there is also a panicle nucleus proximity concentration gradient).

However, ions transported through ion channels (e.g., nerve cells.

Action potentials are generated.

does not require energy consumption, but is a cautious passive transport process along the concentration gradient (see ion channels in the figure above).