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219 Cards in this Set
- Front
- Back
What is the simplest collection of matter that can live?
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Cells
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-pass visible light through a specimen
-magnify cellular structures with lenses |
Light Microscopes
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What is the measurement used in microscopy?
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micrometer
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-focus a beam of electrons through a specimen or onto its surcace
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electron microscopes
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provides for detailed study of the surface of a specimen
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scanning electron microscope
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provides for detailed study of the internal ultrastructure of cells
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transmission electron microscope
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takes cells apart & separates the major organelles from one another
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cell fractionation
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used to fractionate cells into their component parts
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the centrifuge
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when do cell parts separate?
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less dense cell parts will separate from more dense cell parts
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have internal membranes that compartmentalize their functions
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eukaryotic cells
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several basic features that all cells have in common
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-pasma membrane
-cytosol (a semifluid substance) -organelles -chromosomes & ribosomoes |
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site of protein synthesis
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chromosomes & ribosomes
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-do not contain a true nucleus
-no nuclear envelope -dna located in nucleoid -have a cell wall |
prokaryotic cells
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-membranous nuclear envelope
-generally quite a bit bigger -have organelles surrounded by membranes |
eukaryotic cells
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have a higher surface to volume ratio which facilitates the exchange of materials into and out of the cell.
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smaller cells
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-functions as a selective barrier
-allows sufficient passage of nutrients & waste |
plasma membrane
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-phospholipid bilayer
-cholesterol -proteins |
major components of the plasma membrane
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-cell walls
-chloroplast -central vacuole |
things that plants have
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eukaryotic cell's genetic instructions are housed in the
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nucleus
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genetic instructions for which type of cell are housed in the nucleus?
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eukaryotic cells
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the nucleus contains most of the genes in which type of cell?
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eukaryotic
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what contains most of the genes in the eukaryotic cell?
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nucleus
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a discrete unit of hereditary information consisting of a specific nucleotide sequence in DNA
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genes
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encloses the nucleus, separating its contents fromt the cytoplasm
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nuclear envelope
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particles made of ribosomal RNA and protein
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Ribosomes
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site of protein synthesis
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ribosomes
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build proteins in 2 cytoplasmic locates
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ribosomes
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2 cytoplasmic locates in which ribosomes build proteins
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-free ribosomes
-bound ribosomes |
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found floating freely in the cytosol
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free ribosomes
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found attached to the rough endoplasmic reticulum
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bound ribosomes
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-free ribosomes
-bound ribosomes |
proteins synthesize on
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remain in the cell
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free ribosomes
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destined to exit the cell
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bound ribosomes
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various structures in the endomembrane system are related through
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-direct physical continuity
-transfer of membrane segments known as vesicles |
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a sac made of membrane insidee of a cell
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vesicle
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the endomembrane system includes
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the endoplasmic reticulum
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accounts for more than 1/2 the total membrane in many eukaryotic cells
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endoplasmic reticulum
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continuous with the nuclear envelope
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the endoplasmic reticulum membrane (er)
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2 distinct regions of er
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-rough er
-smooth er |
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-contains ribosomes
-produces proteins & membranes (which are distributed by transport vesicles) |
rough er
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lacks ribosomes
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smooth er
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-synthesizes lipids
-metabolizes carbohydrates -detoxifies poison |
functions of smooth er
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broken down in the cells of the liver
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glycogen
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shipping & receiving center
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golgi apparatus
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consists of flattened memranous sacs called cisternae
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golgi apparatus
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side facing the nucleus
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"cis" side
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side facing the plasma membrane
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"trans" side
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receives many of the transport vesicles provided in the rough er
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golgi apparatus
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-modification of the products of the rough er
-manufacture of certain macromolecules |
functions of the golgi apparatus
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side facing the nucleus
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"cis" side
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side facing the plasma membrane
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"trans" side
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receives many of the transport vesicles provided in the rough er
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golgi apparatus
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-modification of the products of the rough er
-manufacture of certain macromolecules |
functions of the golgi apparatus
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-moves from er to golgi
-coalesces with "cis" side of golgi -always go to the cis side -moves from the cis to the trans side -membranes coalesce each time -forms & exits golgi -fuses wtih plasma membrane -doesn't pick up 2 membranes-sheds one than picks up another. |
vesicle proteins within the endomembrane system
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3 methods of moving substances in or out of the cell
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exocytosis & endocytosis
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materials move out of the cell
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exocytosis
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a membranous sac of hydrolytic enzymes that can digest all kinds of macromolecules
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lysosome
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-carry out intracellular digestion
-autophage -apoptosis |
3 processes of lysosome
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involves phagocytosis & lysosomes fuse with food vacuole.
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intracellular digestion
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paramecium: unicellular organism that:
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carries out intracellular digestion
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the cellular uptake of macromolecules & particulate substances by localized regions of the plasma membrane that surround the substance
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endocytosis
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a type of endocytosis involving large particulate substances
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phagocytosis
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macromolecules or substances form vacuoles once inside the cell
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endocytosis
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cytoplasmic extension used for feeding in some cells
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psuedopodia
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food vacuoles are formed by
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phagocytosis
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lysosomes break down damaged organelles within a cell recycles organic molecules
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autophage
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the changes that occur within a cell as it undergoes progammed cell death
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apoptosis
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genetically programmed to break open at a specific time
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lysosomes
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are formed by phagocytosis
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food vacuoles
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pump excess water out of protist cells
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contractile vacuolles
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found in plant cells & hold reserves of importnt organic compounds and water
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central vacuoles
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a complex & dynamic player in the cell's compartmental organization
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the endomembrane system
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a complex & dynamic player in the cell's compartmental organization
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the endomembrane system
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-food
-contracile -central |
types of vacuoles
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change energy from 1 form to anotehr
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mitochondria & chloroplasts
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-sites of cellular respiration
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mitochondria
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glucose molecule is broken down to release energy
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mitochonria
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found in almost all plant & animal cells
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mitochondria
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smootther outer & inner folded into cristae
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mitochondria has 2 membranes
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capture of light energy
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choloroplasts
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-contail chlorophyll
-site of photsynthesis |
chloroplsts
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process in which light energy is converted to the chemical energy in lucose
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photosynthesis
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found in leaves & other green organs of plants & in algae
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chloroplasts
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-thylakoids
-stroma |
parts of chloroplast structure
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membranous sacs
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thylakoids
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internal fluid
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stroma
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a network of fibers extneding throughout the cytoplasm
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the cytoskeleton
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support motility & regulation
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roles of the cytoskeleton
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gives mechanical support to the cell
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cytoskeleton
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involved in cell motility which utilizes motion proteins
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microtubules
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hollow tubes
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microtubules
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shape the cell
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microtubules
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guide movement of organelles
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microtubules
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help separate the chromosome copies in dividin cells
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microtubules
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contain specialized arrangements of microtubules
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cilia & flagella
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locomotor appendages of some cells
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cilia & flagella
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beating pattern
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flagella
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back & forth motion
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ciliary motion
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flagella & ciliary motion
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microtubules
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share a common ultrastructure "9+2" arrangement of microtubules
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cilia & flagella
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9 pairs make a circle & 2 singles are in the middle
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9+2 arrangement of microtubules
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built from molecules of the protein actin
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microfilaments
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involved in amoeboid movement & involves the contraction of actin & myosin filaments
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microfilaments
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another form of locomotion by microfilaments
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cytoplasmic streaming
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exhibits selective permeability & allows some substances to cross it more easily than others
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plasma membrane
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states that a membrane is a fluid structure with a "mosaic" of various proteins embedded in it
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fluid mosaic model of membrane structure
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can move iwthin the bilayer
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phospholipids
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flip flop 1 time per month
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lateral movement
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can drift within the bilayer
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proteins
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-unsaturated hydrocarbon tails (with kinks)
-saturated hydrocarbon tails (more fluid) |
phospholipids may have
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unsaturated hydrocarbon tails
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with kinks
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saturated hydrocarbon tails
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more fluid
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affects the fluidity of the plasma membrane
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the type of hydrocarbon tails in phospholipids
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weged between phospholipid molecules in the plasma memrane of animals
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cholesterol
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molecule with 4 interlockig rings (make the membrane less fluid)
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cholesterol
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a collage of diferent proteins embedded in the fluid matrix of the lipid bilayer
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membrane proteins
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penetrate the hydrophobic core of the lipid bilayer
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integral proteins
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appendages loosely bound to the surface of the membrane
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peripheral proteins
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provide a method of moving a particular solute from one side of the plasma membrane to another
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transport proteins
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-channel
-carrier |
types of transport proteins
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may provide a hydrophillic channel across the mebrane that is selective for a particular solute
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channel proteins
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move a solute across when the protein changes shape
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carrier proteins
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a cell's ability to distinguish one type of neighboring cell from another
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cell-cell recognition
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-sorting of cells into tissues and organs in an animal embryo
-rejection of foreign cells by the immunesystem |
importance of cell-cell recognition
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interaction with the surface molecules of other cells
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cell-cell recognition
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interact with the surface molecule of other cells, facilitating cell-cell recognition
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glycoproteins & glycolipids
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a cell must exchange materials with its surroundings
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a process controlled by the plasma membrane.
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lipid soluble and can pass through the membrane rapidly
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hyrdrophobic molecules
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do not cross the membrane rapidly
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polar molecules
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allow passage of hydrophic substance across the membrane
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transport proteins
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molecules move due to
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thermal energy
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diffusion of a substance across a mebrane with no energy investment
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passive transport
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the tendency for molecules of any substance to spread out evenly into the available space
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diffusion
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there's net diffusion (one side gaining) until
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equilibrium (both sides equal) then there's transfer but no side has more than the other at any given time
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net diffusion
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one side gains
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the movement of substances from an area of higher concentration of that substance to an area of lower concentration
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diffusion
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substances diffuse
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down their concentration gradient
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the difference in concentration of a substance from 1 area to another
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concentration gradient
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membane is permeable to
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water not solutes
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water moves from an area of higher concentration of water to an area of lower concentration of water
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osmosis
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water molecules move from an are of
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lower solute concentration to an area of higher solute concentration (this is backwards in diffusion)
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the ability of a solution to cause a cell to gain or lose water
-has a reat impact on cells without walls |
tonicity
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ideally the molarity
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of the solution outside the cell & inside the cell is the same
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if a solution is isotonic
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the concentration of solutes outside the cell is the same as it is inside the cell
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in comparing 2 solutions referrin to the one with a greater solute concentration
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hypertonic
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if the solution outside the cell is hypertonic then
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the cell will lose water
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in comparing 2 solutios- referring to the one with a lower solute concentration
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hypotonic
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if the solution outside the cell is hypotonic to the cell
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the cell will gain water
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an animal cell (hypotonic solution)
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lysed (water goes in)
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water comes in & out
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isotonic (normal)
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water comes out
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shriveled (hypertonic)
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organisms without rigid cell walls living in hypertonic or hypotonic environments
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must have special adaptations for osmoregulation (has to e able to regulate water flow)
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how organisms regulate solute concentrations & balance the gain & loss of water
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osmoregulation
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name the osmoregulatory device in paramecium
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contractile vacuole
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help maintain water balance
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cell walls
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if a plant cell is turgid
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it is in a hypotonic envionment it is very firm a healthy state in most plants
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if a plant cell is flaccid (limp)
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it is in an isotonic environment
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if a plant cell is in a hypertonic solution
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the cell will lose water to its surroundings & shrink
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water will diffuse
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out of the cytosol & large central auole
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as the plant cell contents shrviels
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its plasma membrane pulls away from the wall
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when the plasma membrane pulls away from the wall
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plasmolysis
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if something wilts
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plasmolysis has occurred
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water comes in when
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turgid (normal
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water coes in & out when
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flaccid
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water comes out when
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plasmolyzed
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can predict the direction in which water will flow
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water potential
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water potential is governed by
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solute concentration & applied pressure
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has to do with cell wall
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applied pressure
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gives scientists a numberical value
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water potential
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pure water has the water potential & molarity
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zero
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adding solutes
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lowers the water potential
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if the water potential of pure water is zero adding solutes
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makes the water potential negative
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water moves
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from an area of high water potential to an area of lower water potential
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diffusion/osmois & facilitated diffusion
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2 types of passive transport
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facilitated diffusion
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usually faster than diffusion
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facilitated diffusion
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no energy & with a concentration gradient
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facilitated
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to help-move faster
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speed the movement of molecules across the plasma membrane
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transport proteins
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specific for the solute & specific binding sites
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transport proteins
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provide corridors that allow a specific molecule or ion to cross the membrane
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channel proteins
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undergo a subtle change in shape that translocates the solute binding site across the mebrane
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carrier proteins
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uses energy to move solutes against their gradients
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active transport
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if you go up a tree
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it takes action (kinetic energy)
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if you're on limb & step off
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it's passive (doesn't take any energy)
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enables a cell to maintain internal concentrations of small molecules that differ from concentrations in its environment
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active transport
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if it requires energy it's in the form of
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atp
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an area of lower concentration to an area of higher concentration
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carrier proteins
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a certain concentration of sodium & potassium ions
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all cells must maintain
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a higher concentration outside the plasma membrane
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sodium
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a higher concentration inside the plasma membrane than outside
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potassium
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for every 3 pumped out of the cell there has to be 2 pumped into the cell
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for every 3 cytoplasmic sodium pumped out of the cell there has to be 2 extracellular potassium ions pumped into the cell
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one type of active transport system
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sodium potassium pump
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higher to lower
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passive transport
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if something goes across the bilayer from higher to lower
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diffusion
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transport & carrier proteins
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facilitate diffusion
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lower to higher concentration
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active transport
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more of 1 type of chemical on one side than on another
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chemical gradient
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the voltage difference across a membrane
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membrane potential
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the inside of the cell
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is negative compared to the outside
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two forces drive
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the diffusion of ions across a membrane
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caused by the concentration electrical gradient of ions across a membrane
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electrochemical gradient
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examples of elctrochemical gradient mechanisms
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-sodium-potassium pump
-prton pump |
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pumps protons or hydrogen ions
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proton pump
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2 examples of electrochemical gradient mechanisms
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both are examples of active transport
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bulk transport across the plasma membrane occurs by
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exocytosis & endocytosis
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exo
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out
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endo
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in
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transport vesicles migrate to teh plasma membrane, fuse with it, & release their contents.
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exocytosis
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the cell takes in macromolecules by formng new vesicles from the plasma membrane
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endocytosis
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phagocytosis, pinocytosis, receptor
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3 types of endocytosis
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large macromolecules are taken in
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phagocytosis
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cell drinking (particles of fluid are taken in)
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pinocytosis
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cell mediated
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receptor
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receptors on outside
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receptor endocytosis
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80% genetics
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metabolism
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the totality of an organisms chemical reactions
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metabolism
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the transformation of one type of matter to another type of matter
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law of thermodynamics
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the transformation of oe type of energy to another type of energy
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laws of thermodynamics
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has many steps that are each catalyzed by a specific enzyme
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metabolic pathway
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