Term
| 4 things that all cells have |
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Definition
1. nucleic acids that store & transmit information
2. proteins that perform most of the cell's functions
3. carbohydrates that provide chemical energy, carbon, support, & identity
4. a plasma membrane which serves as a selectively permeable membrane barrier |
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Term
| 3 broad domains of organisms |
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Definition
1. bacteria
2. archaea
3. eukarya |
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Term
| the most prominent structure inside a bacterial cell is the _____ |
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Definition
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Definition
| segments of DNA that contain information for building functional RNAs, some of which may be used to mae polypeptides |
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| the location & structural organization of the circular chromosome in bacteria |
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Definition
| small, usually circular, supercoiled DNA molecules in bacteria |
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Term
| _____ are observed in all prokaryotic cells & are found throughout the cell interior |
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Definition
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Definition
| a membrane-bound compartment inside the cell that contains enzymes or structures specialized for a particular function |
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Term
| 4 tasks of bacterial organelles |
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Definition
1. storing calcium ions or other key molecules
2. holding crystals of the mineral magnetite which function like a compass needle to help cells sense a magnetic field & swim in a directed way
3. organizing enzymes responsible for synthesizing complex carbon compounds from carbon dioxide
4. sequestering enzymes that generate chemical energy from ammonium ions |
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Definition
| inside the membrane, all contents of the cell excluding the nucleus |
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Term
| cell wall (bacteria & archaea) |
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Definition
| tough, fibrous layer that surrounds the plasma membrane |
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Definition
| lipids that contain carbohydrate groups |
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Definition
| needlelike projections that extend from the plasma membrane of some bacteria & promote attachment to other cells or surfaces |
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Term
| bacteria/archaea VS eukaryotes: location of DNA |
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Definition
b/a: in nucleoid (not membrane bound); plasmids also common
e: inside nucleus (membrane bound); plasmids extremely rare |
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Term
| bacteria/archaea VS eukaryotes: internal membranes & organelles |
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Definition
b/a: extensive internal membranes only in photosynthetic species; limited types & numbers of organelles
e: large numbers of organelles; many types of organelles |
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Term
| bacteria/archaea VS eukaryotes: cytoskeleton |
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Definition
b/a: limited in extent, relative to eukaryotes
e: extensive - usually found throughout volume of cell |
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Term
| bacteria/archaea VS eukaryotes: overall size |
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Definition
b/a: usually small relative to eukaryotes
e: most are larger than prokaryotes |
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Definition
| the fluid portion between the plasma membrane & organelles |
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Term
| 2 key advantages of compartmentalization (organelles) |
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Definition
1. incompatible chemical reactions can be separated
2. chemical reactions become more efficient |
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Definition
| a complex double membrane that encloses the nucleus |
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Definition
| fibrous proteins that form a lattice-like sheet that is linked t the inside of the nuclear envelope |
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Term
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Definition
| where RNA molecules found in ribosomes are manufactured & the large & small ribosomal subunits are assembled |
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Definition
| an extensive membrane-enclosed factory formed from portions of the nuclear envelop that extend into the cytoplasm |
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Definition
| the interior of any sac-like structure in a cell or body |
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Term
| smooth endoplasmic reticulum (SER) (smooth ER) |
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Definition
| contains enzymes that catalyze reactions involving lipids |
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Definition
| consists of discrete flattened, membranous sacs called cisternae which are stacked on top of one another |
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Definition
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Definition
| the lysosomes, Golgi apparatus, & endoplasmic reticulum |
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Term
| vacuole function in seeds |
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Definition
| filled with proteins to provide amino acids for the growing individual |
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Term
| vacuole function in cells that make up flower petals or fruits |
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Definition
| filled with colorful pigments |
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Term
| vacuole function in leaves/stems |
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Definition
| packed with noxious compounds that protect them from being eaten by predators |
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Definition
| a single membrane organelle that originates as a bud from the ER; center for redox reactions |
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Definition
| specialized peroxisomes in plants that are packed with enzymes that oxidize fats to form a compound that can be used to store energy for the cell |
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Definition
| sac-like structure connected to the inner membrane of the mitochondria |
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Definition
| the solution enclosed within the inner membrane of the mitochondria |
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Term
| nucleus: membrane, components, function |
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Definition
m: double ("envelope"); openings called nuclear pores
c: chromosomes; nucleolus; nuclear lamina
f: information storage & transmission; ribosome subunit assembly; structural support |
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Term
| ribosomes: membrane, components, function |
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Definition
m: none
c: complex of RNA & proteins
f: protein synthesis |
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Term
| rough ER: membrane, components, function |
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Definition
m: single; contains receptors for entry of selected proteins
c: network of branching sacs; ribosomes associated
f: protein synthesis & processing |
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Term
| smooth ER: membrane, components, function |
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Definition
m: single; contains enzymes for synthesizing phospholipids
c: network of branching sacs; enzymes for synthesizing or breaking down lipids
f: lipid synthesis & processing |
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Term
| Golgi apparatus: membrane, components, function |
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Definition
m: single; contains receptors for products of rough ER
c: stack of flattened, distinct cisternae
f: protein, lipid, & carbohydrate processing |
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Term
| lysosomes: membrane, components, function |
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Definition
m: single; contains proton pumps
c: acid hydrolases (catalyze hydrolysis reactions)
f: digestion & recycling |
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Term
| vacuoles: membrane, components, function |
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Definition
m: single; contains transporters for selected molecules
c: varies - pigments, oils, carbohydrates, water, or toxins
f: varies - coloration, storage of oils, carbohydrates, water, or toxins |
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Term
| peroxisomes: membrane, components, function |
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Definition
m: single; contains transporters for selected macromolecules
c: enzymes that catalyze oxidation reactions; catalase (processes peroxide)
f: oxidation of fatty acids, ethanol, or other compounds |
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Term
| mitochondria: membrane, components, function |
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Definition
m: double; inner contains enzymes for ATP production
c: enzymes that harvest energy from molecules to make ATP
f: ATP production |
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Term
| chloroplasts: membrane, components, function |
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Definition
m: double; plus membrane-bound sacs in interior
c: pigments; enzymes that use light energy to make sugars
f: production of sugars via photosynthesis |
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Term
| cytoskeleton: membrane, components, function |
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Definition
m: none
c: actin filaments; intermediate filaments; microtubules
f: structural support; movement of materials; in some species, movement of whole cell |
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Term
| plasma membrane: membrane, components, function |
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Definition
m: single; contains transport & receptor proteins
c: phospholipid bilayer with transport & receptor proteins
f: selective permeability - maintains intracellular environment |
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Term
| cell wall: membrane, components, function |
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Definition
m: none
c: carbohydrate fibers running through carbohydrate or protein matrix
f: protection, structural support |
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Term
| 5 steps of the secretory pathway |
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Definition
1. protein enters ER while being synthesized by ribosome & is processed; one or more carbohydrate groups are often added
2. protein exits ER inside a vesicle, travels to cis face of Golgi apparatus
3. protein enters Golgi apparatus & is processed as the cisterna matures
4. protein exits Golgi apparatus in a vesicle & moves to plasma membrane once its cisterna has matured & moved to the trans face
5. protein is secreted from cell |
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Term
| 5 steps of the signal hypothesis |
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Definition
1. signal sequence is synthesized by ribosome
2. signal sequence binds to signal recognition particle (SRP) & halts synthesis
3. SRP binds to receptor in ER membrane
4. SRP is released; protein synthesis continues; protein enters ER
5. signal sequence is removed; protein synthesis then proceeds to completion |
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Term
| 5 steps of protein sorting & vesicle transport |
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Definition
1. in the endomembrane system, proteins bound for different destinations carry distinct tags that serve as molecular zip codes
2. proteins are sorted in the Golgi when they bind to different receptors
3. transport vesicles bud off the trans face of the Golgi & travel to their destinations
4. proteins on vesicle surface interact with receptors at destination
5. vesicle delivers contents |
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Term
| 5 steps of receptor-mediated endocytosis |
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Definition
1. macromolecules outside the cell bind to membrane proteins that act as receptors
2. the plasma membrane folds in & pinches off to form an endocytic vesicle
3. the endocytic vesicle fuses with an early endosome, activating protons that lower its pH; cargo is released & empty receptors are recycled to the surface
4. the early endosome matures into a late endosome that receives digestive enzymes from the Golgi apparatus
5. the late endosome matures into a functional lysosome & digests the endocytosed macromolecules |
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Term
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Definition
1. a damaged organelle is enclosed with a membrane
2. the membrane-bound organelle is delivered to a lysosome, which takes it in & begins digesting it
3. small molecules from the digested organelle are released into the cytosol |
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Term
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Definition
1. the plasma membrane detects a smaller cell or food particle & begins to engulf it
2. the resulting membrane-bound vesicle is a phagosome
3. the phagosome is delivered to a lysosome which takes it in & begins digesting it
4. small molecules from the digested food particles are released into the cytosol |
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Term
| actin filaments (microfilaments): structure, subunits, functions |
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Definition
st: strands in a double helix; -end and +end; 7 nm
su: actin
f: maintain cell shape by resisting tension (pull); move cells via muscle contraction or cell crawling; divide animal cells in two; move organelles & cytoplasm in plants, fungi, & animals |
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Term
| intermediate filaments: structure, subunits, functions |
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Definition
st: fibers wound into thicker cables; 10 nm
su: keratins, lamins, or others
f: maintain cell shape by resisting tension (pull); anchor nucleus & some other organelles |
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Term
| microtubules: structure, subunits, functions |
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Definition
st: hollow tube; -end and +end; 25 nm
su: alpha & beta-tubulin dimers
f: maintain cell shape by resisting compression (push); move cells via flagella or cilia; move chromosomes during cell division; assist formation of cell plate during plant cell division; move organelles; provide tracks for intracellular transport |
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