Studied by 4 people
Anton van Leeuwenhook
Father of Microbiology. discovered cells with microscope
Surface Area : Volume ratio
Surface area must be larger than volume so material can pass through the cell membrane
Matthias Scheliden and Theodor Schwann
hypothesized cells have a life of their own (cell theory)
cell theory
all living things are made of cells, cells are the basic unit of life, cells arise from pre-existing cells, hereditary info is passed from cell, all cells have basic chemical composition, energy flow occurs within cells
3 main parts of a cell
cell membrane, nucleus, cytoplasm
cytosol
mix of water, ions, protons, and sugar. organelles are suspended in this substance
defining characteristic of eukaryotes
nucleus
cytoplasm
collective of cytosol, organelles, and all other cellular components
eukaryotes have this structure, but prokaryotes do not.
nucleus
ribosomes
smaller and simpler in prokaryotes, synthesize proteins
plasmids
freely floating DNA in prokaryotes
nucleoids
cluster of DNA, nucleus-like structure
cell membrane
regulates what passes through the cell
cell wall
rigid, provides protection, encloses cell membrane
capsule
provides protection, sticky layer of proteins, helps bacteria stick to surfaces
pili
protein filaments, helps movement and sticking to surfaces, used for conjugation/reproduction
flagella
long slender cellular projections, used for motion like a propeller
functions of the nucleus
store DNA
chromatin
tightly packed DNA with specific proteins bound together
nucleoplasm
fluid inside nucleus, chromatin suspended here
nucleolus
dense region of protein and nucleic acids; ribosomes made here
Nuclear envelope
membrane that surrounds nucleus, made of lipid bilayer
components of nucleus
DNA, chromatin, nucleoplasm, nucleolus, nuclear envelope
endomembrane system
modifies, transports, and packages proteins and lipids in the cell
organelles in the endomembrane system
vesicles, endoplasmic reticulum, golgi body
vesicles
sacs formed by budding; cell taxi
endoplasmic reticulum (ER)
made from nuclear envelope. ribosomes give it a rough appearance. cell taxi
golgi body
"finishing touches" on proteins and lipids from ER. makes membrane proteins/lipids, protein for secretion, enzymes
organelles
cell organ system
exocytosis
moving something inside the cell to the outside
mitochondria
breaks the sugar bonds to make ATP
chloroplasts
specific type of plastid; photosynthesis
plastid
organelle in plants and algae that help with photosynthesis, storage, and pigmentation
cytoskeleton
interconnected protein filaments that reinforce, organize, and move cell structures
microtubules
hollow cylinders; movement and shape
microfilaments
support plasma membrane and movement
intermediate filaments
stable framework; structure and strength
motor proteins
activated by ATP, move materials throughout cell
cilia
short hair-like structures projecting from cell
pseudopods
temporary stretched lobe, moves and grabs prey
cell junctions
structures that connect a cell to other cells and the environment
tight junctions
animal cells. fasten cell membranes of adjacent cells together, keep bodily fluid contained
adhering junctions
animal cells. make up cardiac muscles and skin
Gap junctions
animal cells. closable channels between cells; let substances flow quickly between cells
plasmodesmata
plant cells. open channels between cytoplasm of two cells, similar to gap junction in animal cells.
