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Some substances, such as fructose molecules, need a little assistance to enter and exit cells.
Proteins imbedded in the cell membrane lightly bind to these substances and then change shape to allow the substance to move across the cell membrane.
This process is called facilitated diffusion.
In facilitated diffusion, substances are moved from an area of high concentration to an area of lower concentration.
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∙ 14y ago
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∙ 12y agoThey are assisted by specific proteins in the membrane called carrier proteins.
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∙ 13y agonon-polar molecules like fatty acids and retinol are transported through facilitated diffusion
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∙ 13y agoUsually water is diffused although other simple nutrients can be passed through as well.
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∙ 9y agoWhite blood cells
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∙ 14y agosugar
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∙ 10y agopills
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∙ 11y agoglucose
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Substances that move across a cell membrane without using energy?
by simple diffusion, facilitated diffusion, and osmosis.
How does CO2 cross the cell membrane?
No, carbon dioxide does not need a transport protein to cross the cell membrane. It can pass through a membrane by diffusion.
When a substance moves across the plasma membrane along a concentration gradient at a rate faster than would be expected by simple diffusion alone but without the expenditure of metabolic energy?
It is called facilitated diffusion. It is a type of passive transport.
What is a transport process by which gases move through a membrane?
Simple Diffusion
What moves small or lipid soluble solutes through the membrane?
The unassisted diffusion of solutes through the plasma membrane is called simple diffusion. Solutes transported this way are either lipi-soluble (fats, fat-soluble vitamins, oxygen, carbon dioxide) or small enough to pass through the membrane pores (some small ions such as chloride ions, for example).
What happens in simple diffusion?
In simple diffusion, a substance passes through a membrane without any outside intermediary. The rate of diffusion is based on the force exerted..
Oxygen crosses the plasma membrane by?
Simple diffusion process, i.e. from high pressure to low pressure
Which substance may enter a cell membrane by simple diffusion?
Water, certain ions, air and glucose molecules.
How can oxygen cross the membrane?
By the process of simple diffusion.
Substances that move across a cell membrane without using energy?
by simple diffusion, facilitated diffusion, and osmosis.
How does CO2 cross the cell membrane?
No, carbon dioxide does not need a transport protein to cross the cell membrane. It can pass through a membrane by diffusion.
How does nitric oxide cross the plasma membrane?
Simple Diffusion
Where in the eukaryote membrane do simple diffusion take place?
Cytoplasm
How simple diffusion can be distinguished from facilitated diffusion?
simple diffusion transports smaller molecules like oxygen and water while facilitated diffusion transports larger molecules like glucose and requires energy
What determines whether carbon dioxide is absorbed or released by blood?
The rate at which carbon dioxide enters the cell is determined by the concentration of carbon dioxide on each side of the membrane. Carbon dioxide crosses the plasma membrane by simple diffusion.
How the terms in each pair differ in meaning of osmosis and diffusion?
Osmosis is the diffusion of water through a selectively permeable membrane. Diffusion refers to the simple property of moving from an area of high concentration to an area of low concentration so that the concentration of the total area will be equal and balanced (at equilibrium). Diffusion can occur with any substance and does not require but can involve a permeable membrane.
The process by which simple sugar passes through a membrane is called?
diffusion
