Cell Energy Prep
This structure surrounds every cell and controls movement into and out of it.
Plasma membrane
Molecules moving from high concentration to low concentration without ATP are using this general type f transport
Passive transport
Particles are more concentrated outside a cell than inside. If they were allowed to cross the membrane freely, their net movement would be in this direction.
Into the cell
A difference in concentration of a substance across a membrane is called this
Concentration gradient
ATP is useful to cells because it can transfer this to cellular processes
Energy
These structures build proteins using instructions carried from DNA
Ribosomes
A molecule moves down its concentration gradient through a membrane protein. Name the process.
Facilitated diffusion
A cell is placed in a hypotonic solution. Predict what happens to its volume.
It increases
When ions are unevenly distributed across a membrane, both concentration and charge can effect their movement. Together these make this type of gradient.
Electrochemical gradient
A membrane suddenly becomes freely permeable to H+. What will happen to the existing H+ gradient?
This organelle modifies and packages proteins for transport
Golgi apparatus
Water moving across a selectively permeable membrane is called this
Osmosis
A cell is placed in an isotonic environment. Predict the net movement of water.
Zero
Moving ions against their electrochemical gradient requires an input of this
Energy
A cell keeps pumping H+ to one side of a membrane, but the H+ immediately leaks back across. What would be the result in potential energy?
None would accumulate
This organelle will become especially important when we study how cells extract usable energy from glucose
The mitochondrion
A cell moves Na+ from low concentration to high concentration. Name the type of transport.
Active transport
A membrane is permeable to K+ but not to large negatively charged proteins. K+ is more concentrated inside the cell. Which way will K+ initially move, and what effect will that have on charge inside the cell?
K+ moves out, making the inside more negative
A cell uses ATP to pump H+ ions to one side of a membrane. What type of energy has it stored?
Potential energy
A membrane pump uses ATP to move H+ against its gradient. What happens to the energy from ATP?
It is stored as potential energy in the H+ gradient
Both mitochondria and chloroplasts contain many internal membranes. Explain one advantage of having extensive membrane surface area.
Providing more space for membrane-bound reactions, space for electrochemical gradients
A cell has much higher Na+ concentration outside than inside. Na+ enters through a channel, and the energy released by that movement is uesd to move glucose into the cell against its gradient. What type of transport is this?
Secondary active transport
H+ is more concentrated outside a cell than inside, but the inside of the cell is positively charged. Why can you not predict H+ movement by concentration alone?
Both the concentration gradient and the electrical gradient affect ion movement
H+ was pumped across a membrane using energy. It later flow back down its concentration gradient through a protein. Explain how this movement could do work for the cell.
The stored potential energy of the gradient can be transferred to another process.
When two atoms share electrons unequally, what property determines which atom pulls the shared electrons more strongly?
Electronegativity