Admin Table of Contents
- 1 What process moves molecules from low to high concentration?
- 2 What structure allows molecules to move from low to high concentration across the membrane?
- 3 What is the name of the process by which molecules move from a high concentration to a lower concentration without using up any energy?
- 4 What types of molecules are shown moving across the membrane?
- 5 When molecules move down their concentration gradient they move from where they are?
- 6 How are molecules transported across the cell membrane?
- 7 How are water molecules cross the plasma membrane?
What process moves molecules from low to high concentration?
Key terms
| Term | Meaning |
|---|---|
| Osmosis | The net movement of water across a semipermeable membrane from an area of lower solute concentration to an area of higher solute concentration |
| Tonicity | The ability of an extracellular solution to make water move into or out of a cell by osmosis |
What structure allows molecules to move from low to high concentration across the membrane?
Passage through a channel protein allows polar and charged compounds to avoid the hydrophobic core of the plasma membrane, which would otherwise slow or block their entry into the cell. Image of a channel protein, which forms a tunnel allowing a specific molecule to cross the membrane (down its concentration gradient).
Which process allows the movement of molecules that are too large to pass in through a cell membrane?
ENDOCYTOSIS AND EXOCYTOSIS: MOVEMENT OF LARGE PARTICLES It is possible for large molecules to enter a cell by a process called endocytosis, where a small piece of the cell membrane wraps around the particle and is brought into the cell. If the particle is solid, endocytosis is also called phagocytosis.
What is it called when molecules move from high to low concentration through a carrier protein?
No expenditure of energy is required. As its names suggests, diffusion is still important in this mechanism. Molecules, like sugars, reach the carrier proteins in the membrane by diffusion and are then moved across the membrane from a region of high concentration to a region of low concentration.
What is the name of the process by which molecules move from a high concentration to a lower concentration without using up any energy?
Diffusion
Simple Diffusion One example of passive transport is diffusion, when molecules move from an area of high concentration (large amount) to an area of low concentration (low amount). Molecules are said to naturally flow down their concentration gradient. This type of diffusion proceeds without an input of energy.
What types of molecules are shown moving across the membrane?
What types of molecules are shown moving across the membrane? Small nonpolar or small polar molecules.
What molecules are too big for diffusion?
Glucose molecules are too big to diffuse through the cell membrane easily, so they are moved across the membrane through gated channels. In this way glucose diffuses very quickly across a cell membrane, which is important because many cells depend on glucose for energy.
Where do molecules move in active transport?
In active transport, the particles move across a cell membrane from a lower concentration to a higher concentration. Active transport is the energy-requiring process of pumping molecules and ions across membranes “uphill” – against a concentration gradient.
When molecules move down their concentration gradient they move from where they are?
When molecules move down their concentration gradient, they move from where they are more concentrated to where they are less concentrated. Diffusion across a biological membrane is called passive transport.
How are molecules transported across the cell membrane?
1 Diffusion. Diffusion is a process of passive transport in which molecules move from an area of higher concentration to one of lower concentration. 2 Osmosis. 3 Tonicity. 4 Facilitated transport. 5 The Role of Passive Transport. 6 Primary Active Transport. 7 Electrochemical Gradient.
How does osmosis work to transport water across a membrane?
Osmosis is the movement of water through a semipermeable membrane according to the concentration gradient of water across the membrane, which is inversely proportional to the concentration of solutes.
How does a molecule move down the concentration gradient?
A molecule moves down its concentration gradient using a transport protein in the plasma membrane. This is an example of Nice work! You just studied 71 terms! Now up your study game with Learn mode.
How are water molecules cross the plasma membrane?
Water can cross the plasma membrane through the process of facilitated diffusion. However, water molecules can also cross the lipid bilayer directly. The sodium-potassium pump uses energy from ATP to move sodium ions out of the cell, and potassium ions into the cell.