Passive Transport
No.
Does active transport require energy?
Yes.
What molecule is moving in/out of cells in osmosis?
Water
What macromolecule makes up most of the cell membrane?
Lipids/phospholipids
Define osmosis.
Water moving into/out of cells.
In passive transport, molecules always move (toward/away) from crowded spaces.
Away
In active transport, molecules move from areas of __________ (High/low/equal) concentration to areas of ___________ (High/low/equal) concentration.
Low, high
What happens when a cell is placed in a hypertonic solution?
It shrinks as water leaves it.
Phospholipids are made of a _____________ (hydrophobic/hydrophilic) head and ____________ (hydrophobic/hydrophilic) tails.
Hydrophilic, hydrophobic
What is facilitated diffusion?
Passive transport requiring a transport protein.
What kind of macromolecule does facilitated diffusion use to move large molecules into/out of cells?
Proteins
What is the name of the energy molecule used in active transport?
What happens when cells are put in an isotonic solution?
Nothing. It stays the same size.
What kinds of molecules can diffuse through the cell membrane without help?
Small, nonpolar
What is concentration?
The amount of "stuff" in a space.
When something is moving "down" a concentration gradient, it is moving from an area of ____________ (higher/lower/equal) concentration to one with a ____________ (higher/lower/equal) concentration.
Higher, lower
What is the difference between endocytosis and exocytosis?
Endocytosis = brings things into the cell, exocytosis = pushes things out of the cell
A freshwater plant is suddenly placed into a container filled with seawater. What will happen to its cells? Tell me if its hypo/hyper/isotonic.
Hypertonic (water rushes out)
What is the name of the model we use to describe the cell membrane?
Fluid mosaic
What is phagocytosis?
Cell eating. Cells engulf stuff.
Red blood cells carry oxygen through your body and deliver it to cells in need. When oxygen arrives to a cell, it needs to pass through the membrane in order to get inside. If this molecule is nonpolar, will it enter through simple diffusion or facilitated diffusion?
Facilitated diffusion
A cell has a lot of K+ inside it. When put in a solution with low K+, the cell expands as K+ enters. A student adds a chemical, and K⁺ uptake stops. The K+ is unchanged, so the chemical isn't doing anything to the potassium. What is the chemical probably doing?
Stopping ATP/sapping away the energy.
An athlete is trying to stay hydrated and drinks lots of water. His coach tells him to make sure he gets plenty of electrolytes (a type of salt). He doesn't listen and gets water intoxication, which means his blood salt levels are very low due to the amount of water he drank. Why did this happen? I.e. did water move into or out of his cells?
His cells are hypotonic, because there is more salt in his cells than in his blood. Water rushes in.
When the membrane pinches off to make a mini-membrane that carries food and other materials, it is called a ___________
Vesicle
Define dynamic equilibirum.
Equal concentrations both inside and outside the cell, but the molecules continue to move in and out.