Studied by 3 peopleunicellular
a single cell; bacteria, yeasts, tiny algae
multicellular
a group of a few to many cells; plants and animals
cell diversity
cells vary greatly in size and shape
cell theory
all organisms are made up of cells
the cell is the fundamental unit of life
cells come from preexisting cells
features of all cells
a cell membrane
an ability to store, use, and transmit information
the ability to transfer energy from the environment
cell membrane
also known as the plasma membrane, surrounds all cells and controls the exchange of material with the environment; maintains the conditions inside a cell
homeostasis
the active maintenance of stable internal conditions in the face of a changing external environment; requires energy
ribosome
a complex structure of RNA and protein that synthesizes proteins from mRNA
metabolism
the chemical reactions occurring within cells that convert one molecule into another and transfer energy in living organisms
ATP (adenosine triphosphate)
the molecule that provides energy in a form that all cells can readily use to perform the work of the cell; enables cells to carry out many functions, including growth, division, and moving substances into and out of the cell
Catabolism
part of metabolism; the set of chemical reactions that break down molecules into smaller units, and in the process, release energy in the form of ATP and heat
anabolism
another part of metabolism; the set of chemical reactions that build molecules from smaller units and require an input of energy, usually in the form of ATP
nucleus
the compartment of the cell that houses the DNA in chromosomes
cytoplasm
the region of the cell outside of the nucleus
prokaryotic cells
cells without a nucleus; archaeons and bacteria
eukaryotic cells
a cell that has a nucleus; animals, plants, fungi, and protists
domains
one of the three largest limbs of the tree of life: eukarya, bacteria, or archaea
prokaryotic cell features
no nucleus, small, has nucleoid, plasmids, cell wall, cell membrane, flagella (some)
simple and unicellular organisms
nucleoid
where the DNA of prokaryotes is; typically organized as one circular molecule of DNA arranged in many loops
cell wall (prokaryotes)
made of peptidoglycan, a complex polymer of sugars and amino acids
plasmids
smaller circular molecules of DNA; carries a few genes
eukaryotic cell features
has nucleus, linear DNA, nuclear membrane, and organelles
complex and multicellular organisms
has a cell membrane, cytoplasm, nucleus, ribosomes, mitochondria, cilia (some),
Differences between prokaryotes and eukaryotes
prokaryotes have no nucleus, eukaryotes have a nucleus
prokaryotes are typically much smaller than eukaryotes
eukaryotes have organelles
prokaryotes include bacteria and archaea, eukaryotes include animals, plants, fungi, and protists
surface area
the total area of the outside surface of an object
vesicles
a small membrane-enclosed sac that transports substances within the cell; transports proteins produced by the E.R. to the cell membrane, other organelles of the endomembrane system, or the cell exterior
endomembrane system
the interconnected membranes of the cell; present in eukaryotic cells; includes the cell membrane, nuclear envelope, endoplasmic reticulum, Golgi apparatus, lysosomes, and vesicles
cytosol
space outside the organelles
nuclear envelope
the two membranes, inner and outer, that define the boundary of the nucleus
nuclear pores
large protein complexes that regulate which molecules move into and out of the nucleus
endoplasmic reticulum
an organelle composed of a network of membranes that is involved in the synthesis of proteins and lipids; bound by a single membrane
golgi apparatus
further modifies and sorts proteins and lipids produced by the endoplasmic reticulum; often the next stop for vesicles that bud off the ER; major site where carbohydrates are added to proteins and lipids
glycosylation
occurs predominantly in the Golgi apparatus in which sugars are covalently linked to lipids or proteins
lysosomes
a vesicle derived from the Golgi apparatus that contains enzymes that break down macromolecules and excess materials; acidic environment for its enzymes
mitochondria
specialized organelles; site of cellular respiration in eukaryotic cells, harnesses energy from organic molecules such as carbohydrates to produce ATP; contains their own DNA
cellular respiration
a series of chemical reactions in which organic molecules are oxidized to carbon dioxide, converting the energy stored in organic molecules to ATP; oxygen is used to synthesize ATP, and carbon dioxide is released as a waste product
intermembrane space
the space between the inner and outer membranes
mitochondrial matrix
the space enclosed by the inner membrane
chloroplasts
organelles that capture the energy of sunlight to synthesize simple sugars aka photosynthesis (where carbon dioxide is consumed and oxygen is released as a waste product)
thylakoid
a flattened sac within the chloroplast that is bounded by membranes where the light-dependent reactions (calvin-cycle) of photosynthesis occur
cytoskeleton
an internal protein scaffold that helps cells to maintain their shape; helps determine cell shape
microfilaments
a cytoskeletal element that are thin, helical protein fibers and can be found just underneath the cell membrane, where they help to maintain cell shape
microtubules
a cytoskeletal element that are hollow tubes and radiate outward from the cell center, and help support the cell and provide tracks for vesicles and other organelles
cell wall
absent in animal cells, present in plants, algae, fungi, and bacteria; maintains cell size and shape; mainly made up of carbohydrates and proteins
turgor pressure
pressure within a cell resulting from the movement of water into the cell by osmosis
vacuole
absorbs water and contributes to turgor pressure
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