Unit 2 Flashcards
Chapters 6+7
Light Microscopes
Allow for images of living processes in which light is passed through a stained specimen
Electron Microscopes
Can get a detailed and much more magnified image as electrons are traveling through the unstained speciman
Cell Fractionation
The process that deconstructs cell parts (organelles) by separating them by force
Centrifuge
The machine that spins the specimen being fractionated
Supernatant
The liquid separated from the dense pellet after cell fractionation. This part contains the cell parts not being studied
Eukaryotic Cells
Cells that have compartmentalized sections (organelles) that carry out specific processes, a nucleus, and are often multicelled organisms
Prokaryotic Cells
Cells that are much smaller, contain no organelles or nucleus, and usually exist as a unicellular organism
Nucleoid
The unbound region in a prokaryotic cell where DNA is stored
Flagella/Cilia
Extracellular expenditures that are responsible for cellular movement in prokaryotes (and select eukaryotes)
Nuclear Envelope
The membrane that separates the nucleus from the cytoplasm
Nuclear Pores
Microscopic pores on the nucleus that regulates which substances exit and enter the nucleus, most commonly mRNA
Nuclear Lamina
The fluid area between the double membrane of the nucleus that helps maintain its shape
Nucleolus
The dense area within the nucleus responsible for rRNA synthesis
Ribosomes
Non-membrane bound structures that are responsible for protein synthesis in all cells
Endomembrane System
The collection of organelles that regulate protein traffic (Nuclear envelope, ER, Golgi, Lysosome, Vauole, Plasma Membrane)
Vesicle
Membrane-bound proteins that transport materials across the cell
Glycoproteins
Proteins covalently bonded to carbohydrates used for cell signaling
Golgi Apparatus
The membrane-bound organelle that modifies ER products and sorts them into transport vesicles
Lysosome
Organelle found in animal cells that uses hydrolytic enzymes to break down large macromolecules
Phagocytosis
The process in which the cell engulfs another cell, forming a food vacuole. The lysosome then fuses with the food vacuole to digest the molecules inside
Autophagy
When lysosomes digest and recycle organelles that aren’t being used by the cell by breaking them down
Vacuole
Large vesicles originating from the ER/Golgi that are used for storage
Mitochondria
Double membrane-bound organelles that carry out cellular respiration and contain their own proteins, ribosomes, and DNA
Chloroplasts
Double membrane-bound organelles found in plants where photosynthesis occurs. They contain chlorophyll, thylakoids, ribosomes, DNA, and stroma
Endosymbiont Theory
This theory proposes that mitochondria and chloroplasts were once their own prokaryotic cells that were engulfed by a larger eukaryotic cell. This theory is supported by the fact that mitochondria and chloroplasts have a double-membrane, contain free ribosomes and DNA, and grow and reproduce (split) independently within the cell
Plastids
Name given to organelles specific to plants
Peroxisomes
Specialized oxidative organelles that monitor hydrogen peroxide (H2O2) levels by decomposing H2O2 into water and oxygen
Cytoskeleton
The network of fibers throughout the cytoplasm that organizes organelles (fits them in place) and provides structural support for the cell
Microtubules
Hollow rods that shape the cell and place organelles on tracks to be anchored in place. They also are responsible for chromosome separation during cell division
Centrosome
Where microtubules grow out of in animals cells
Centrioles
Compose the centrosome, made of 3 triplets of microtubules arranged in a ring
Microfilaments
The solid rods arranged in a twisted double chain made of actin subunits that bear tension within the cell
Pseudopodia
Extracellular extensions that allow cells to “crawl” across a surface
Cytoplasmic Streaming
The flow of cytoplasm within the cell which is important for the distribution of materials and nutrients
Intermediate Filaments
Permanent fixtures that support cell shape and fix organelles in place
Cell Wall
The extracellular surrounding layer in plant cells and prokaryotes that protects the cell from its environment and allows for increased water intake
Extracellular Matrix (ECM)
The system made of glycoproteins in animal cells that regulate cellular behavior by communicating with other cells
Integrins
Receptor proteins found in the membrane of animal cells
Cell Junctions
The cellular communication (by adhering/interacting) through direct physical contact via tight junctions, desmosomes, and gap junctions
Amphipathic
When a molecule contains both hydrophobic and hydrophilic regions
Fluid Mosaic Model
States that the cell membrane is made up of various parts that contribute to its fluidity (proteins, carbohydrates, cholesterol)
Cholesterol
Type of lipid that can stabilize membrane fluidity when temperatures change
Peripheral Proteins
Proteins bound to the surface of the membrane either on the extracellular side or the cytoplasmic side
Integral Proteins
Membrane proteins embedded in the phospholipid bilayer
Transmembrane Protein
Membrane proteins that stretch the entire width of the phospholipid bilayer (poking out at each end)
Channel Proteins
Transport proteins with a hydrophilic channel that allow for the straight passage of charged particles
Carrier Proteins
Transport proteins with hydrophilic bonding sites that change shape when bonded and “push” the molecule through the phospholipid bilayer
Aquaporins
Channel proteins specific for the facilitation of water across the membrane
Diffusion
The tendency for molecules to spread out evenly in order to maintain an equal concentration
Dynamic Equilibrium
When concentrations across a membrane are equal yet molecules keep diffusing, just in equal ratios
Passive Transport
Diffusion of a substance across a membrane with NO outside energy expended by the cell
Facilitated Diffusion
Passive transport assisted by a transmembrane protein
Osmosis
The diffusion of water
Water Potential
The potential energy/probability of water movement from one solution to another due to solute potential and pressure potential. Water always flows to an area of lower water potential
Tonicity
The ability solutions to cause water loss or gain within the cell
Isotonic
When the solute concentration of a solution equals the solute concentration of the cell and there is no net movement
Hypertonic
When the solute concentration of a solution is greater than the solute concentration of the cell and diffusion occurs in favor of the higher solute conc (the solution)
Hypotonic
When the solute concentration of a solution is less than the solute concentration of the cell and diffusion occurs in favor of the higher solute conc (the cell)
Plasmolysis
When the plasma membrane of a plant cell contracts away from the cell wall due to excessive water loss
Osmoregulation
The control of solute concentration to maintain water balance within a system, necessary for adaptation
Active Transport
The diffusion of substances against their concentration gradient in which extra energy is required
Membrane Potential
The voltage difference across a membrane. The cell is charged with a slight positive emphasis on its extracellular side and a slight negative emphasis on its cytoplasmic side
Electrochemical Gradient
The combination of chemical and electrical forces that drive the diffusion of ions across a membrane
Electrogenic (Proton) Pump
A transport protein that generates a voltage (pressure to push ions through)
Cotransport
Occurs when active transport of a solute indirectly drives the transport of another substance
Exocytosis
When vesicles fuse with the membrane to release its waste contents out of the cell
Endocytosis
When the cell takes in macromolecules by allowing for a membrane to fold inside
Pinocytosis
When a cell intakes fluid and nutrients from outside the cell via vesicle
Receptor-Mediated Endocytosis
When a cell acquires specific substances due to receptor proteins on the extracellular side of the plasma membrane that bind with the desired molecules before being engulfed
