Ch. 4 Tour of the Cell Flashcards
Plasma Membrane
Thin layer of lipids and proteins that sets a cell off from its surroundings and acts as a selective barrier to the passage of ions and molecules into/out of the cell
- consists of phospholipid bilayer
Cytoplasm
Everything inside a cell b/w the plasma membrane and nucleus; semi fluid medium and organelles
Organelle
A structure with specialized function in cell. Membrane bound.
Light Microscope
An optical instrument with lenses that refract (bend) visible light to magnify images and project them
- only up to 1000 times
- magnification and resolving power
Micrograph
Photograph thru microscope
Magnification
Increase in apparent size of an object
- multiply ocular by objective lens
Resolving Power
Clarity of an image
- distinguish one object from another
Cell Theory
All living things are composed of cells and all cells come from other cells
Electron Microscope
An instrument that focuses on a electron beam thru/onto a specimen
- electromagnets and beam of electrons
- dead organisms due to vacuum
- 2 types: Scanning and Transmission
Scanning Electron Microscope
Studies the details of the cell’s outer surface
Transmission Electron Microscope
Studies the details of internal cell structures
What does cell size vary upon?
Function. It also relates to surface area to volume ratio.
- Big enough for cytoplasm, DNA, and needed molecules
Prokaryotic Cell
A type of cell lacking a membrane enclosed nucleus/organelles
- Bacteria/Archaea
- small/primitive
- lack ability to make internal membranes (thus organelles)
Nucleoid Region
Region with concentrated mass of DNA (direct contact with cell contents)
Ribosomes
Organelle of RNA and protein that functions as a protein synthesis site
Bacterial Cell Wall
Rigid cell wall surrounding plasma membrane to protect cell/maintain shape
Capsule
Sticky layer that surrounds bacterial cell wall
- protects and glues cell to surfaces
Pili
Short projections on cell surface that attach to others
Prokaryotic Flagella
Long cell surface projection ion that propels cell thru liquid environment
Eukaryotic Cells
Cell with membrane enclosed nucleus and other organelles (eukarya)
- compartmentalization
Cellular Metabolism
Chemical activities of cells occurs in fluid w/in organelles so multi-tasking possible
- needs homeostasis
Nucleus
Genetic control center of a eukaryotic cell
- surrounded by nuclear envelope
Function: DNA synthesis, RNA synthesis, assembly of ribosomal units
Chromatin
Combo of DNA and proteins that constitute eukaryotic chromosomes (long fibers)
Chromosome
Thread-like, gene-carrying structure most visible in mitosis/meiosis
Nuclear Envelope
Double membrane, perforated with pores, that encloses the nucleus and separates it from the rest of the eukaryotic cell
Nucleolus
Structure in nucleus where RNA is made and assembled with proteins
Endomembrane System
Network of membranous organelles that partition the cytoplasm of eukaryotic cells into functional compartments
Endoplasmic Reticulum
Extensive membranous network continuous w/ outer nuclear membrane and composed of rough/smooth regions
- manufacture/package
Rough ER
Network of interconnected membranous sacs in a eukaryotic cell’s cytoplasm studded with ribosomes that make membrane proteins
Function: Synthesis of membrane protein, secretory protein, hydrolytic enzymes; formation of transport vesicles
Secretory Protein
Protein secreted from the cell (ex. antibody)
Smooth ER
Network of interconnected membranous tubules in cell’s cytoplasm
Function: Lipid synthesis, carbohydrate metabolism in liver cells, detoxification, calcium ion storage
Golgi Apparatus
Organelle consisting of stacks of membranous sacs that modify, store, and ship products of the endoplasmic reticulum
Function: Modification, temporary storage, transport macromolecules, formation of lysosomes/transport vesicles
Lysosome
Digestive organelle in eukaryotic cells; contains hydrolytic enzymes that digest cell’s food/waste.
- only animals
Function: Digestion of nutrients/bacteria/damaged organelles; destruction of cells
Vacuoles
Membrane enclosed sac (in endomembrane system) with various functions
Central vacuole
Membrane enclosed sac occupying most of the interior of a plant cell with diverse role in reproduction, growth, and development
Chloroplasts
Organelle found in plants and photosynthetic protists; enclosed by two concentric membranes; site of photosynthesis
- stroma, thylakoids, grana
Function: Light energy to chemical energy of sugars
Mitochondria
An organelle in eukaryotic cells where cellular respiration occurs; enclosed by 2 concentric membranes, it is where cell’s ATP is made from sugars
- inter membrane space and mitochondrial space
Function: Chemical energy to ATP
Cristae
fold of inner membrane of a mitochondrion; enzymes embedded in it to make ATP
Cytoskeleton
Framework of fine fibers that extend thru cytoplasm that function as structure/shape
- microfilaments, intermediate filaments, microtubules
Function: Shape, anchor organelles, movement of cell/organelles, signal transmission
Microfilaments
Thinnest of 3 protein fibers of cytoskeleton; a solid helical rod composed of globular protein actin; help some cells chance shape/move by assembling at one end and disassembling at another
- cell contraction
Intermediate filaments
An intermediate sized protein fiber that is one of of 3 making up cytoskeleton; rope like, made of fibrous proteins
- reinforcing for tension, anchoring organelles
Microtubules
Thickest of 3 fibers making up cytoskeleton; straight hollow tube made of globular proteins called tubulins; basis of structure and movement of cilia/flagella
- disassembled/reused
- anchoring/tracking movement of organelles
Cilia
Short, numerous appendages that propel protists
Flagella
Long, generally less numerous appendages on other protists (9:2 ratio)
Cell Junctions
A structure that connects tissue cells to one another
Plasmodesmata
An open channel in a plant cell wall, through which strands of cytoplasm connect form adjacent walls (allows cells to pass molecules)
Extracellular Matrix
A substance in which the cells of an animal tissue are embedded consists of protein/polysaccharides
- helps hold cells in tissues w/ protection/support
Tight Junctions
Junction that binds tissue cells together in a leakproof sheet
Anchoring Junctions
Junction that connects tissue cells to each other and allows materials to pass from cell to cell.
Communicating Junctions
Channel b/w adjacent tissue cells through which water and other small molecules pass freely
What are the 4 categories of Eukaryotic cell organelles?
1) Manufacture
2) Breakdown/Recycle
3) Energy Processing
4) Support/Movement/Communication
