Membrane & Solution Concentrations
Transport Mechanisms
100
Which major macromolecule makes up the cell membrane? Proteins, carbohydrates, lipids, or nucleic acids?
Lipids - specifically phospholipids
100
What is the difference between active and passive transport?
Active transport requires energy (ATP) to move molecules against their concentration gradient
Passive transport doesn't require ATP and molecules move down their concentration gradient
200
What is the fluid mosaic model?
Model that describes the cell membrane as mosaic since it is made up of various different components/proteins/molecules. The 'fluid' portion shows how the cell membrane is constantly moving and is never static.
200
What are the 2 kinds of passive transport?
1. Simple diffusion: molecules move down their concentration gradient without the help of any protein channels - they move through the membrane
2. Facilitated diffusion: molecules move down their concentration gradient using protein channels to help them go through the membrane
300
Define hypertonic, isotonic, and hypotonic solution.
Hypertonic: a solution that is high in solute concentration relative to a cell.
Isotonic: a solution that is balanced in solute concentration relative to a cell.
Hypotonic: a solution that is low in solute concentration relative to a cell.
300
What type of transport is demonstrated in the figure? Endocytosis or exocytosis? Define this process.
Endocytosis: the process of molecules entering the cell by using the cell membrane to form a vesicle around the molecule.
ex. Cholesterol is picked up by liver cells using endocytosis
hint: endo = inside/within
400
Using this figure, where will the water move? What is this process called?
Water will go down its concentration gradient so into the right side of the tube through osmosis.
water likes to go where the party is.
400
What transport mechanism is illustrated in the figure below? Endocytosis or exocytosis? Describe this process.
Exocytosis: when the cell releases molecules by forming a vesicle around the molecules, which will fuse into the membrane and exit the cell.
ex. neurons release chemical signals called neurotransmitters using exocytosis so that they can communicate with other neurons/cells
500
What happens if I placed a cell in a hypertonic, isotonic, and hypotonic solution?
Hypertonic: cell shrinkage
Isotonic: cell is stable
Hypotonic: cell swelling and bursting (lyse)
500
1. ________ is the process by which the cell engulfs water (liquid).
2. ________ is the process by which the cell engulfs solid objects such as a pathogen, also known as 'cell eating'
1. Pinocytosis
2. Phagocytosis