Unit 2 - Cells Flashcards
All other forms of life - have a membrane bound nucleus
Eukaryotic Cell
Bacteria/ archea
Prokaryotic Cell
Phospholipids from a two-layer sheet in the membrane
Phospholipid Bilayer
Face outward and are exposed to water
Hydrophilic heads
Face inward and are shielded from water
Hydrophobic Head
Proteins embedded in the phospholipids and can drift about in the phospholipids
Fluid Mosaic (Membranes)
Attach the extracellular matrix on the outside of the cell as well as span the membrane to attach to the cytoskeleton
Integrins
Cross membrane easily (I.e. CO2 and O2)
Nonpolar molecules
Do not cross membrane easily (i.e. Glucose and other sugars)
Polar molecules
A process in which particles spread out evenly in available space
Move from high to low concentrations, eventually particles reach equilibrium
Diffusion
Diffusion across a cell membrane and does not require energy
Passive Transport
Water moves across a membrane in response to a solute concentration inside and outside of the cell by a process called
Osmosis
Osmosis will move across a membrane down its [blank] until the concentration of solute is equal on both sides of the membrane
Concentration Gradient
Describes the ability of a solution to cause the cell to gain or lose water
Tonicity
Concentration of solute is same on both sides, equilibrium
Isotonic
Concentration of Solute is higher outside of the cell
Hypertonic
Concentration of solute is higher inside the cell
Hypotonic
The ability of organisms to maintain water balance within their cells by a process called
Osmoregulation
Specific transport proteins that transport necessary substances across the membrane
Aquaporins
Used to export bulky molecules such as proteins or polysaccharides (out of the cell)
Exocytosis
Used to import substances useful for the livelihood of the cell (in the cell)
Endocytosis
Engulfment of a particle by wrapping the cell membrane around it, forming a vacuole (cell eating)
Phagocytosis
Fluids are taken into small vesicles (cell drinking)
Pinocytosis
Receptors in a receptor-coated pit interact with a specific protein; will not close until receptors are full
Receptor-Mediated Endocytosis
Potential Energy bc of energy available for release in a chemical reaction
Chemical Energy
A chemical reaction that releases energy - comes from breaking bonds
Exergonic Reaction
The measure of the disorder/randomness of energy
Entropy
Requires an input of energy and yields products rich in potential energy
Endergonic Reaction
All your Exergonic and endergonic reactions combined within you
Metabolism
A series of chemical reactions that either break down a complex molecule or build up a complex molecule
Metabolic Pathway
Three types of cellular work
Chemical work
Transport work
Mechanical work
Driving endergonic reactions
Chemical work
Pumping substances across membranes
Transport work
Beating of a cilia
Mechanical Work
To accomplish work, a cell must manage energy sources. It does so by
Energy Coupling
The immediate source of energy that powers most forms of cellular work - energy currency of cells
ATP - Adenosine Triphosphate
When energy is released in an Exergonic reaction, such as the breakdown of glucose, the energy is used in an endergonic rxn to generate ..
ATP
When the plasma membrane controls the movement of molecules into and out of the cell - based on the structure of the membrane w/it’s component molecules
Selective Permeability
