Part 2: Cells Flashcards
Light microscopes
Compound microscopes, used to study stained/living cells, magnify up to 1000x
Cells
Most basic unit of life
Electron microscopes
Used to study detailed structures of cells that can’t be seen under light microscopes
Scanning-uses electron beam to scan surface and project 3D image back
Transmission-cross section of cell
Eukaryotic cells
Membrane-enclosed organelles
Large (for cells)
Linear DNA-in nucleus
Fungi/protists/plants/animals
Prokaryotic cells
Circular DNA- floats freely in cell
No membrane enclosed organelles
Cell wall
Bacteria and archae
Plasma membrane
Phospholipid bilayer with embedded proteins
Regulates movement of substances in and out of the cell- semipermeable
Peripheral proteins
Loosely associated with bilayer, on inner or outer surface of membrane
Integral proteins
Firmly bound to plasma membrane, amphipathic
Transmembrane proteins don’t extend all the way through
Fluid-mosaic model
Membrane phospholipids are fluid, proteins make it a mosaic
Adhesion proteins
Form junctions between adjacent cells
Receptor proteins
Docking sites for ECM or hormones
Transport proteins
Pumps that use ATP to actively transport solutes across membrane
Channel proteins
Allow for passage of select molecules or ions across membrane
Recognition and adhesion proteins
Play a role in cell recognition and adhesion
Carbohydrate side-chains
Part of ECM, found attached to some proteins
Cholesterol
Stabilize membrane fluidity in animal cells, keeps it from being greatly influenced by temperature
Chromosomes
Organized DNA
Used in cell division
Nucleolus
Site of RNA synthesis and ribosome assembly
Ribosomes
Sites of protein synthesis
Free or bound
Endoplasmic reticulum
Continuous channel that extends into the cytoplasm
Rough- studded with ribosomes, site of protein synthesis
Smooth- detox, makes lipids
Golgi body
Packaging and shipping
Package things in vesicles
Produce lysosomes
Mitochondria
Powerhouses of the cell
Convert energy from organic molecules int useful energy (ATP)
Site of cell resp.
ATP
Adenine triphosphate
Energy currency of the cell
Lysosomes
Carry digestive enzymes, used to break down old organelles/debris/ingested particles
Centrioles
Small, paired cylindrical structures found within microtubule organizing centers (mtocs)
Produce microtubules during cell division
In animal, but not plant cells
Vacuoles
Fluid-filled sacs that store water, food, waste, salt, and pigments
Peroxisomes
Break down substances
Hydrogen peroxide is byproduct
Cytoskeleton
Network of fibers that determine shape of cell
Microtubules
Made of protein tubulin
Centrioles, cilia, flagella
Cilia and flagella
Aid in cell movement in watery environments
Euglena
Classic example of organism with flagella
Paramecium
Classic example of organism with cilia
Cell wall
Protective, rigid outer covering of plant cells, fungi cells, protist cells and prokaryotes
Chitin
Modified polysaccharide that makes up fungi cell walls
Chloroplasts
Organelles involved in photosynthesis
Contain chlorophyl - gives plants green color
Cell sap
Contained in vacuole of mature plant cells
Passive transport
Substance moves down the concentration gradient and diffuses through the membrane (or proteins in the membrane)
Osmosis
Diffusion of water
Solutes
Dissolved substances
Channel proteins
Proteins embedded in the plasma membrane that help lipid-insoluble substances move across the membrane
Facilitated diffusion
Diffusion is aided by carrier or channel proteins, but no energy is used (still diffusion)
Active transport
The transport of substances against the concentration gradient, requires energy (ATP)
Sodium-potassium pump
Example of active transport carrier protein
Endocytosis
For extremely large particles, part of the cell forms a pocket around the substance, pinches it in, and forms a vesicle that contains the substance
Pinocytosis
Cell drinking, small gulps
Phagocytosis
Cell eating, very large particles
Receptor-mediated Endocytosis
Ligand starts process in which receptor with ligand bound to it is brought into the cell: cell folds in and forms vesicle around ligand, carries it to interior of cell
Bulk flow
One-way movement of fluids brought about by pressure
Blood flow, xylem/phloem fluids
Dialysis
Diffusion of solutes across a selectively permeable membrane
Exocytosis
Cell releasing waste products or specific secretion products
Intercellular junctions
Connections between cells that involve plasma membranes and other components
Desmosomes
Animal cells, like a rivet
Gap junctions
Channels between cells- cells share cytoplasm
Tight junctions
Cells pressed up tightly against one another, connected by proteins in ECM
Plasmodesmata
Gap junctions of plant cells
