Cell Structure
This boundary surrounds every cell and regulates exchange with its surroundings.
What is the plasma membrane?
Oxygen moves through a membrane from higher to lower concentration without a transport protein.
What is simple diffusion?
A plant cell gains water, and its contents push more firmly against the cell wall. Name the resulting pressure.
What is turgor pressure?
Name the ratio used to compare a cell’s exchange surface with the amount of material inside it.
What is surface area to volume ratio?
A cell makes large amounts of protein for export. These tiny structures attached to its endoplasmic reticulum assemble the proteins.
What are ribosomes?
Water crosses a membrane through a specialized channel. Name the channel.
What is an aquaporin?
An animal cell is placed in a solution with a higher concentration of nonpenetrating solute than its cytoplasm. Predict its change in size.
What is shrinking? (smaller)
A cube has 24 mm² of surface area and 8 mm³ of volume. Give its surface area to volume ratio.
What is 3:1 (or 3 mm⁻¹)?
A protein destined for secretion has left the rough ER. This organelle modifies, sorts, and ships it.
What is the Golgi apparatus?
Glucose moves down its concentration gradient through a carrier protein without cellular energy input.
What is facilitated diffusion?
A plant cell loses water until its plasma membrane pulls away from its cell wall.
What is plasmolysis?
Two similar shaped cells have radii of 2 µm and 6 µm. How many times greater is the larger cell’s surface area?
What is 9 times?
A digestive enzyme enclosed in a membrane bound compartment helps break down worn cell parts. Name the compartment.
What is a lysosome?
A membrane protein moves ions from low concentration to high concentration using energy from ATP.
What is active transport?
Two solutions have different water potentials, Solution A has −4 bars and Solution B has −11 bars. State the direction of net water movement.
What is from side A (−4) bars toward side B (−11) bars?
A large cell develops many membrane folds without a comparable increase in volume. What happens to its surface area to volume ratio?
A cell can run different chemical reactions in separate internal spaces. Name this organizational advantage of membrane bound organelles.
What is compartmentalization?
A drug stops ATP production, yet a molecule continues moving down its gradient through a protein channel. Explain why movement can continue.
What is movement by facilitated diffusion, which does not require ATP?
Tissue pieces show no net mass change in a particular sucrose solution. What does that tell you about the water potentials of the tissue and solution at that point?
What is that their water potentials are equal?
What is −7 bars?