How can you tell if it s active transport or free spread?

First of all, it is mainly by judging the concentration difference, free diffusion is transported from high concentration to low concentration (i.e., along the concentration difference), and active transport is transported against the concentration difference.

In addition, active transport requires energy consumption (ATP) and also requires the help of membrane proteins, but free diffusion can be formed spontaneously and does not require the participation of energy** and carrier proteins.

Finally, it is safest to remember some common types of material transport: small molecules such as oxygen, carbon dioxide, glycerol, hydrolipids (mostly gases) or hydrophilic and lipophilic substances can be transported by free diffusion; For example, potassium ions, sodium ions and other inorganic salt ions (which play an important role in maintaining the osmotic balance of cells, and can also cause nerve impulses in nerve cells to transmit information) or hydrogen ions, and some amino acid molecules are all actively transported across the membrane.

If it is a larger molecule or substance (silica particles, invading bacteria and viruses, etc.), it is achieved by endocytosis and exocytosis.

1. Look at the direction of transportation, low to high is active, and high is free diffusion.

2. Look at the carrier, the one with the carrier is active, 3, look at the energy, the one who wants energy is the active, 4, remember several common ones, ions, amino acids active, water, gas, fat-soluble molecules diffuse freely.

Free diffusion is an autonomous diffusion from low to high concentrations (e.g. water, oxygen, carbon dioxide, glycerol, ethanol) that does not require a carrier or energy

Active transport requires carriers and energy, generally from high to low concentrations (e.g., inorganic salt ions) to assist in diffusion, and only one is glucose uptake by small intestinal epithelial cells.

Please, give me some points.

As mentioned in the biology book, cells such as lipids, gases, and macromolecular substances do not have to be free diffusion, and K+, amino acids, etc., must be actively transported. Active transport requires carrier proteins, which require energy to take place.

Don't look at the rest, just look at whether the energy consumption and the need for the carrier should be the concentration to a certain extent affect the transportation speed.

What requires energy and carriers is active transport!

Assist in proliferationand free diffusion is passive transport, which is carried out along the concentration gradient of substances without consuming cellular metabolic energy (ATP); Active transportationis active, regardless of concentration.

Assisted diffusion, free diffusion, and cytocytocytosis do not consume energy, and active transportation requires a certain amount of energy to be consumed.

Peculiarity. Active transport is not only to borrow the middle hand with the help of the mosaic in the cell membrane.

The specific delivery of protein molecules on the ground (i.e., each substance is transported by a specialized carrier) and must also be done by consuming the energy produced by cellular metabolism.

First, carrier proteins.

Energy is obtained from the energy released by ATP water and converted into an activation carrier, which combines with substances inside or outside the membrane to form a complex called an ion pump or proton pump.

Assisted diffusion generally refers to facilitated diffusionThe transmembrane transport of substances through the membrane is mediated by special proteins (including carriers and channels) on the membrane, and the paraelectro-chemical gradient is carried out. There are two main modes of transport: one is carrier-mediated facilitated diffusion; The second is channel-mediated facilitated diffusion.

Facilitated diffusion belongs to passive transport, and the main characteristics of passive transport are: the process of transporting substances does not need to consume energy, and it is a "passive" process with the "help" of special proteins on the cell membrane to carry out transmembrane transport along the concentration gradient or potential gradient.

Channels to assist in diffusion:

Different channels have different permeability to different ions of the finger bonds, i.e., ion selectivity, which is determined by the structure of the channel, allowing only ions with a specific ion radius and charge to pass through.

According to the different ion selectivity, the channels can be divided into sodium channels, calcium channels, potassium channels, chlorine channels, etc. However, the ion-selectivity of the channel is only relative rather than absolute, for example, sodium channels are permeable to ammonia ions in addition to being mainly permeable to sodium ions, and even slightly permeable to potassium ions.

Active Transport, Free Proliferation and Assisted Proliferation? The concept must be understood, otherwise it is useless to give more examples. Active transport refers to the process by which a substance is transported into or out of the cell membrane under the action of energy with the assistance of a carrier against the concentration gradient (moving from low to high concentration).

Such as potassium, proton transport, amino acids, nucleotides, polysaccharides, peptides, and even proteins. Generally speaking, it is a substance with a larger molecule and fewer ions in the cell. Free diffusion means that substances are transported from the high side through the cell membrane to the side with low concentration, such as O2, CO2, N2, glycerol, ethanol, benzene and other substances, which can be transported from the side with high concentration to the side with low concentration, and this mode of transport does not require energy.

Generally, they are small molecules and fatty substances. Gas: CO2O2 Lipids:

Glycerol, fatty acids (similarly compatible) Small molecule organics: ethanol, benzene, urea

Assisted diffusion, also known as facilitated diffusion, refers to a mode of transportation in which non-fat-soluble substances or hydrophilic substances, such as amino acids, sugars and metal ions, enter the membrane without consuming ATP with the help of membrane proteins on the cell membrane. This is not energy-consuming, and is much faster than free diffusion because of the help of protein, so it is more orderly and faster. Such as calcium, iron ions, Na+, NH4+, 3,

Facilitated diffusion. It is membrane protein-mediated passive diffusion. That is, facilitated diffusion.

The main features are:

1. Facilitated diffusion requires the help of membrane proteins.

2. The facilitated diffusion with the help of membrane proteins can reach the maximum, and when the transmembrane concentration difference of the solute reaches a certain level, the speed of facilitated diffusion no longer increases.

3. In facilitated diffusion, transport proteins have a high degree of selectivity. For example, transport proteins can help glucose.

Fast shipping, but does not help in the transportation of sugars that are structurally similar to glucose.

4. The facilitated diffusion of transport proteins will also be inhibited in various ways.

1. Different directions: copy

1. Free diffusion: substance.

Transport from the side with high concentration through the cell membrane to the side with low concentration.

2. Active transport: the transport of substances along the inverse chemical concentration gradient (i.e., the movement of substances from the low concentration area to the high concentration area).

Second, the situation of the need for the carrier is different:

2. Free diffusion: no carrier required.

2. Active transport: with the help of a specific transport protein molecule embedded in the cell membrane as a carrier (that is, each substance is transported by a special carrier).

3. The energy consumption is different:

3. Free diffusion: It does not need to consume the energy released by intracellular metabolism, and is a simple mode of transportation;

2. Active transport: It needs to consume the energy generated by cellular metabolism to complete.

Fourth, the process is different:

1. Free diffusion: the substances that are selected to be absorbed enter and exit the cell from the high concentration side through the cell membrane to the low concentration side;

2. Active transport: First, the carrier protein obtains energy from the energy released by ATP hydrolysis and converts it into an activated carrier, which combines with substances inside or outside the membrane to form a complex called an ion pump or proton pump.

Fifth, both ways are important for cells.

1. Free diffusion is one of the ways for substances to enter and exit cells through the plasma membrane, and the free diffusion speed of substances is related to the degree of lipid solubility of the substance, the difference in solute concentration between the two sides of the membrane, the size of the solute molecule and the properties of the charge.

2. The way of actively transporting this substance in and out of the cell can ensure that the living cells can actively choose and absorb the nutrients they need according to the needs of life activities, and discharge the waste products produced by metabolism and the substances harmful to the cells.

The material transport mode of the cell membrane is co-du

There are two categories: passive transportation.

zhi (free diffusion and co-dao assisted proliferation) version; Active transportation (sovereign transportation).

Here passive transport refers to the transmembrane transport of cells from high to low concentration, and active transport refers to from low to high concentration. (Methods to distinguish between free diffusion and assisted diffusion: carrier proteins are required for free diffusion, and assisted diffusion is not.)

PS: Carrier proteins are also required for active transport).

Among them, passive transportation requires energy consumption, and active transportation does not require it.

There are three types of substances that can diffuse freely: water, gas molecules such as carbon dioxide, oxygen; To assist in diffusion in the high stages, just remember that glucose enters red blood cells; There are two types of substances that are actively transported: small molecule substances that cells need such as glucose, amino acids, and ions that cells need.

Macromolecules enter the cell: endocytocytosis (macromolecules: proteins, polynucleotides, particles formed by cholesterol and lipoproteins, etc.).

In fact, it is very important for cells, and without any part of the cell's vital activities can not be carried out normally (as can be seen from the various transported substances).

I hope it helps, and if you have any questions, you can ask me.

The power of free diffusion comes from inside and outside the cell membrane.

The difference in permeability, the concentration of the substance in the membrane and the outside of the DAO is the genus of the pressure difference.

The difference is that the matter is transported through free diffusion, which is characterized by the osmotic pressure difference, no energy is consumed, and no carrier is required.

The power of active transport comes from the energy consumption of the cell, which requires the carrier proteins above and inside the cell membrane to assist in transport, even if there is a concentration difference, it can be transported from low concentration to high concentration, and active transport is characterized by energy consumption, which requires carrier proteins, and has nothing to do with the concentration difference.

This is what we learned in biochemistry, and animal physiology also has some related content, I hope it can help you.

High school involves the transmembrane attack of the substance.

There are two main categories of transportation, with a total of three types of bai

Mode: Passive transport (common du is the degree of the concentration gradient, no energy required) is not the same point as: free diffusion:

For example, the main substance of the cell membrane is lipids (phospholipids), so fat-soluble substances such as glycerol are diffused through this pathway; Assisted diffusion: Proteins are required as carriers, but no energy, such as glucose into red blood cells, is required for transport.

Active transport against the concentration gradient, which requires ATP energy provided by organelles such as mitochondria, chloroplasts, or cytoplasmic matrix for transport, requires a carrier.

There are three types of material transport in cell membranes: active transport, passive transport, and free diffusion. Active transport requires carrier and ATP, passive transport requires carrier, and free diffusion does not require carrier and ATP. The various transport and transport substances are different, and they are all important.

There are three differences:

1. Free diffusion, from high concentration to low concentration; Active transport, is low to high concentration.

2. Free diffusion: no carrier required. Active transport, carriers are required.

3. Free diffusion, no energy consumption; Active transportation, which requires energy consumption.

Free diffusion is a biological term that refers to the transport of substances from the side with high concentration through the cell membrane to the side with low concentration, such as O2, CO2, N2, glycerol, ethanol, benzene and other substances, which can be transported from the side with high concentration to the side with low concentration. The way this substance enters and exits the cell is called free diffusion. Free diffusion does not require the consumption of energy released by intracellular metabolism and is a simple mode of transportation.

This method is called passive transportation in contrast to active transportation.

Active transport refers to the process of transporting substances into or out of the cell membrane under the action of energy with the assistance of a carrier 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, requiring the assistance of carrier proteins and consuming the energy released by intracellular chemical reactions. The range of high school exams is not very wide, and it is enough to remember a few special ones.

One needs a carrier, the other doesn't.

Both free diffusion and assisted diffusion are passive transport, and substances can only be transported from a high-concentration area to a low-concentration area, and no energy is required in the process. The difference between the two is that free diffusion does not require a carrier, while assisted diffusion requires the participation of a carrier.

Active transport requires not only the assistance of a carrier, but also the consumption of energy, and the substance can be transported against the concentration gradient.

Free diffusion does not consume energy, nor does it require the assistance of carrier proteins, relying on the concentration difference between the inside and outside of the cell membrane, from high concentration to low concentration, mainly the transfer mode of some small molecules.

Assisted diffusion does not require energy, but requires carrier proteins, which also rely on the concentration difference between the inside and outside of the cell membrane, from high concentration to low concentration.

Active transport requires energy and carrier proteins, which can be transported from low to high concentrations by reversible concentration gradients.

Answer 1: The substances transported are different: the substances that are actively transported, assisted diffusion, and freely diffused are all ionic and polymer substances; Whereas, endocytosis and exocytosis are the transportation of macromolecular substances. 2. The way in which substances enter and exit the cell is different:

Assisted diffusion and free diffusion are passive transports, which are carried out along the concentration gradient of substances without consuming cellular metabolic energy (ATP); Active transport is active, regardless of concentration; The current mode of transportation of endocytosis is controversial and cannot be judged as active or passive transportation. 3. Whether it needs to consume energy is different: assisted diffusion, free diffusion and endocytocytosis do not consume energy, and active transportation requires a certain amount of energy.