In active transport,
molecules move across the plasma membrane against their concentration gradient.
A molecule moves down its concentration gradient using a transport protein in the plasma membrane. This is an example of
The sodium-potassium pump uses energy from ATP to move sodium ions out of the cell, and potassium ions into the cell. This is an example of
The plasma membrane forms a pocket that pinches inward, forming a vesicle that contains material from outside the cell. This describes the process of
"Conservation of energy" refers to the fact that _____.
energy cannot be created or destroyed but can be converted from one form to another
In your body, what process converts the chemical energy found in glucose into the chemical energy found in ATP?
An enzyme is considered a(n)____ because it speeds up a chemical reaction without being used up.
the ______between an active site and its substrate often strains bonds and helps the reaction proceed.
high temperatures or changes in pH can _____ an enzyme, causing it to lose its shape and biological activity.
What cannot pass directly through the phospholipids of the plasma membrane?
Charged atoms and molecules (ions)
You know that this cell is in a(n) _____ solution because it _____.
hypertonic solution ... lost water
The plasma membrane is selectively permeable. Which of the following can pass freely through the membrane with no assistance?
oxygen and carbon dioxide
In oil-based liquids, phospholipids are arranged so that their _____ face outward and their _____ are orientated inward.
hydrophobic tails ... hydrophilic heads
The movement of molecules from an area of higher concentration to an area of lower concentration is called _____.
When water moves toward the solution with the _____ solute concentration, the solution is _____.
greater ... hypertonic
Our cells require glucose to produce energy. Consider a cell where the external concentration of glucose has dropped to 5%, but the internal concentration is at 20%. How does the cell obtain more glucose?
Energy can be classified as either potential or kinetic. Which of the following is an example of kinetic energy?
a running child
Through an _____ reaction, ATP is hydrolyzed into ADP by _____ and _____ energy.
exergonic ... losing a phosphate group ... releasing
During enzymatic reactions, substrates are converted to products. A property of enzymes that facilitates this reaction is that they are catalysts and therefore _____.
change the rate of a reaction without being consumed by the reaction