Science C2 Flashcards
describe the cell as an open system
it exchanges matter and energy within its environment so that it may acquire nutrients, excretes wastes and other cellular products. This is controlled by the cell membrane
describe tonicity; hypertonic, isotonic, and hypotonic solutions and their effects on the movement of materials through membranes (water), including those of cells.
in a hypertonic- water would move out of the cell
the membrane is
selectively permeable to maintain equilibrium/homeostasis
the membrane contains
a phospholipid bilayer and proteins
passive transport
uses kinetic energy, particle movement from an area of higher concentration to an area of lower concentration. Also the movement of substances through the cell membrane without the use of cellular energy.
Active Transport
requires energy to move particles (ATP) which is created through cellular respiration. Particles move from areas of low to high concentration.
Concentration Gradient
A difference in concentration of molecules. No extra energy (ATP) is required to move molecules down (with) a gradient; from an area of high to low concentration. Energy is required to move molecules up (against) a gradient; from an area of low to high concentration.
Diffusion
Type of passive transport; movement of particles from an area of higher concentration to an area of lower concentration through vesicles. Diffusion continues until all particles are evenly spread out; are in equilibrium. The rate of diffusion can be increased by adding energy and increasing molecular movement. (heating or stirring)
Osmosis
the diffusion of water across a membrane that is
permeable to water, but not the solute (semi-permeable). (high to low), (Passive transport).
Tonicity
refers to the concentration of a solution in comparison
to that of another.
Isotonic
= same as cell (Doesn’t change the shape of a cell) equal salt and water concentration
Hypotonic
= less solute, more water (turgid). Causes cell to swell through osmosis.
Hypertonic
= more solute, less water. Causes cell to shrink
Facilitated diffusion
the movement from higher to lower concentration, but with proteins facilitating the movement. (Water-soluble
substance need assistance in the form of a protein channel or carrier protein in order to move across the cell membrane.) (Doesn’t need energy).
Active Transport with Carrier Proteins (protein pump)
Similar to facilitated diffusion, but requiring energy to move molecules from a low to a high concentration.
May bring needed entities into the cell or expel materials from the cell.
Endocytosis
Process by which a cell takes in material by forming a vacuole/membrane around it. Require energy from ATP for the rearrangement of the cell membrane.
Types of Endocytosis: Phagocytosis and Pinocytosis
Phagocytosis involves the intake of larger molecules (cell eating). Pinocytosis is the engulfment of liquid and dissolved molecules (cell drinking).
Exocytosis
Active transport that uses vesicles to remove wastes and cell products from a cell. Requires energy from ATP for the rearrangement of the cell membrane.
Transport Protein
Used to help substances enter or exit cell membrane
Carrier protein
transport protein that changes shape when a particle binds with it. Pump that helps move materials from low to high con.
Channel protein
Transport protein that provides a tube-like opening in the plasma membrane through which particles can diffuse.
Protein pump
capable of pumping out compounds that could pose a threat to the cell.
Phospholipid
Made of a phosphate head and a fatty tail. The head loves water, tail hates water.
(READ) If a cell wants to move a substance from an area with a LOW concentration to an area of HIGH concentration, it needs to use ENERGY to PUMP the substance AGAINST its CONCENTRATION GRADIENT.
This is called active transport and uses carrier proteins and ATP (energy)
Peritoneal dialysis (membrane tech)
Peritoneal dialysis uses the peritoneal membrane to remove/filter out solutes and water from the body fluids of patients with end-stage renal disease.
Observation from iodine and starch lab
The bag is permeable to iodine, but not to the starch. Starch is a bigger molecule while iodine isn’t so iodine is more permeable
Observation from egg lab
The syrup solution was more concentrated so the egg shrunk. The water solution was less concerned and had more water so the egg expanded
