Cell Membranes and Membrane Transport Flashcards
What kind of molecule can diffuse directly through the phospholipid bilayer?
Small and nonpolar molecules
How are molecules moved against the concentration gradient?
Using a carrier protein / pump (active transport) that consumes ATP
What happens to ATP once it is used?
It becomes ADP and releases a phosphate group
Animal cells in a hypotonic solution are called
Lysis, once they burst
Plant cells in a hypotonic solution are called
Turgid
Animal cells in a hypertonic solution are called
Crenated
Plant cells in a hypertonic solution are called
Plasmolyzed
Cells in an isotonic solution are called
Normal
What are the ideal environments for plant and animal cells?
Animal: isotonic (normal)
Plant: hypotonic (turgid)
When a cell is in a hypertonic solution, water moves
Out
When a cell is in a hypotonic solution, water moves
In
How do cells move large materials into the cell?
Endocytosis (vesicle transport)
How do cells move large materials out of the cell?
Exocytosis (vesicle transport)
What organelle controls vesicle transport?
Golgi apparatus
What is the main pump function in a nerve cell?
Sodium-potassium pump – 3 sodium ions out for each 2 potassium ions in
“Cell eating”
Phagocytosis
“Cell drinking”
Pinocytosis
When moving along the concentration gradient, which direction requires no energy input?
Down
What are the three types of passive transport?
Diffusion (across the bilayer), facilitated diffusion (through channel proteins), and osmosis (water through an aquaporin)
What are lipid-soluble molecules?
Nonpolar molecules
Which proteins are attached to only one side of the membrane?
Peripheral proteins
Which proteins span the bilayer?
Integral proteins
What are glycolipids, and what are their function?
Glycolipids are lipids with a carbohydrate attached that regulate cell recognition (like a fingerprint).
What are glycoproteins, and what are their function?
Glycoproteins are proteins with a carbohydrate attached that help the immune system and are involved in recognition and communication
What is the function of cholesterol in the cell membrane?
Cholesterol (a lipid) strengthens the cell membrane and makes it more stable
What are the three main types of membrane transport?
Passive (channel proteins, no energy required), active (carrier proteins, ATP required), and vesicle transport (for large molecules)
Receptor protein
Receives signal molecules and creates a response
Enzymatic protein
“catalyzes biochemical reaction at the membrane”
How do lipid-soluble molecules move through the cell membrane?
Through the bilayer
How do polar molecules move through the cell membrane?
Through integral proteins
