Term
| what are the characteristics and functions of all cells |
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Definition
1. cell metabolism/ energy use
2. synthesis of molecules
3. communication
4. reproduction/inheritance |
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Term
membrane potential
inside vs outside of cell? |
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Definition
an electrical charge difference across the membrane
(result of cells regulation of ion movement)
outside of cell= more positively charged |
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Term
| what makes up the plasma membrane? |
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Definition
lipids- ~50%
proteins- ~50%
carbs-~5% |
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Term
glycolipid?
glycoprotein?
glycocalyx? |
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Definition
glycolipid= lipid+carb
glycoprotein= protein+carb
glycocalyx= collection of glycolipids, glycoproteins, and carbs on the outer surface of plasma membrane |
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Term
membrane lipids
what are the main ones?
properties of them? |
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Definition
the main lipids are PHOSPHOLIPIDS and CHOLESTEROL
phospholipids- form a lipid bilayer (double layer of phospholipids) hydrophilic/polar head (exposed to aqueous outer and inner fluids), hydrophobic/non-polar tail (face one another in the interior of the plasma membrane)
cholesterol- interspersed among the phospholipids and limits movement of phospholipids, providing stability of the p membrane |
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Term
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Definition
| says that the plasma membrane is neither rigid nor static in structure but is highly flexible and can change shape and composition through time |
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Term
membrane proteins
2 types
5 function types |
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Definition
integral-deep into the lipid bilayer of plasma membrane, often extends from one surface to the other. consist of regions made up of amino acids with either hydrophobic or hydrophilic R groups. the hydrophobic regions are located within hydrophobic part of the membrane, the hydrophilic part is located at the inner or outer surface of the membrane or line the channels through the membrane
peripheral proteins- attached to either the inner or outer surfaces of the lipid bilayer
they can function as
1. marker molecules
2.attachment proteins
3.transport proteins
4.receptor proteins
5. enzymes |
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Term
| marker molecules (protein) |
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Definition
| cell surface molecules that allow cells to identify other cells or other molecules. mostly glycoproteins or glycolipids. ex- sperm cell recognition of oocyte, immunity functions, or intracellular communication |
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Term
attachment proteins
2 types |
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Definition
proteins which allow cells to attach to other cells or extraacellular molecules (or intracellular)
cadherins-attach cells to other cells
integrins- attach cells to extracellular molecules, also communicate with intracellular molecules |
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Term
| transport proteins 3 characteristics types? |
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Definition
transport proteins: integral proteins that allow ions/molecules to move from one side of the membrane to the other
specificity-each transport protein binds to/transports only a certain type of molecule
competition- closely related substances with same shape may bind to same transport protein, the substance of greater concentration or one that binds more readily will move across membrane faster
saturation-rate of transport limited to the # of available carrier proteins... once all binding sites are occupied, the rate remains constant
channel proteins- arranged so that they form a tiny channel through the membrane (charges of hydrophilic part of channel proteins determine which ions can pass through)
**nongated/leaky: always open. / responsible for the membranes permeability
**ligand gated- open/close in response to chem signals **voltgage gated- open/close from change in membrane potential or charge
carrier protein- move ions or molecules from one side of the plasma membrane to another. they have specific binding sites to which the molecules attach to one side of membrane. they change shape to move the bound molecule to the other side of the membrane where it is released
**uniporters (one specific molecule), symporters(dif molecules same direction), anti porters (dif molecules in opposite direction)
atp powered pumps- move specific molecules from one side of membrane to other, but unlike carrier proteins these movements are fueled by the breakdown of ATP.**have a binding site for specific molecules AND atp. *the breakdown of atp>adp releases energy, changing the shape of protein which moves the molecule across membrane |
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Term
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Definition
proteins/glycoproteins in the plasma membrane that have an exposed receptor site on the outer cell surface, which can attach to specific chemical signals.
ex- some membrane bound receptor molecules function by altering the activity of a G protein complex located on thinner surface of the p membrane, which acts as an intermediary between receptor and other cellular proteins. g protein complex= alpha, beta, and gamma proteins. |
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Term
membrane proteins
enzymes* |
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Definition
| some membrane proteins function as enzymes, which catalyze chemical reactions on either the inner or the outer surface of the p membrane |
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Term
| the plasma membrane is selectively ____ |
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Definition
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Term
| enzymes, proteins, glycogen, potassium ions have a _________ concentraction _________ |
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Definition
| higher concentration intracellularly |
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Term
| sodium, calcium, chloride have a _________ concentration _______ |
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Definition
| higher concentration extracellulary |
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Term
| oxygen, co2, and steroids are __________ and pass through the membrane readily by dissolving in __________ |
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Definition
lipid-soluble
the lipid bilayer |
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Term
| some ______________ ____________ soluble molecules (urea) can diffuse between the phospholipid bilayer |
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Definition
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Term
| _______ ________ soluble molecules move through the membrane with the help of a transport protein |
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Definition
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Term
| large molecules and even whole cells can be transported through membrane in a _________ |
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Definition
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Term
Diffusion
-passive or active?
-description
-substances?
-example |
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Definition
passive
Random movement of molecules results in net movement from areas of higher>>lower concentration
substances:
Lipid soluble molecules- dissolve in lipid bilayer and diffuse through it
ions/small moleules-diffuse through membrane channels
ex.
Oxygen, carbon diozide, and lipids (steroid hormones) dissolve into lipid bilayer; Cl- and urea move through membrane channels |
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Term
Osmosis
-passive or active?
-description
-substances?
-example |
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Definition
passive
Water diffuses across a selectively permeable membrane
substance: water
ex: water moves from intestines into the blood |
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Term
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Definition
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Term
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Definition
| greater concentration, greater osmotic pressure (less diluted) |
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Term
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Definition
| lower concentration (more dilute) |
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Term
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Definition
| equal, cell remains the same |
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Term
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Definition
| cell shrinks (water moves out) |
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Term
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Definition
| cell swells (water moves in) |
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Term
Facilitated Diffusion
-passive or active?
-description
-substances?
-example |
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Definition
passive
Carrier proteins combine with substances and move them across the plasma membrane, no ATP used, substances always moved from areas of higher to lower concentration. Exhibits the characteristics of (specificity, saturation, and competition)
Some substances to large to pass through membrane channels and too polar to dissolve in the lipid bilayer are transported
Glucose moves by facilitated diffusion into muscle cells and adipocytes |
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Term
Active transport
-description
-substances?
-example |
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Definition
Atp powered pumps combine with substances and move them across the plasma membrane. Atp used. Can move substances from lower to higher concentration. Exhibits characteristics (specificity,competition, saturation)
Some substances to large to pass through membrane channels and too polar to dissolve in the lipid bilayer are transported. Substances that are accumulated in concentrations higher on one side of the membrane than on the other are transported
Ions such as Na+ K+ and Ca2+ are actively transported |
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Term
secondary active transport
-description
-substances?
-example |
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Definition
Ions are moved across the plasma membrane by active transport, which establishes an ion concentration gradient, ATP is required; ions then move back down their concentration gradient by facilitated diffusion, and another ion or molecules moves with the diffusion ion (symport) or in the opposite direction (anti port)
Some sugars, amino acids, and ions are transported
There is a concentration gradient for Na+ into intestinal epithelial cells. This gradient provides energy for the symport of glucose. As Na+ enter the cell, down their concentration gradient, glucose also enters the cell. In many cells H+ are moved in the opposite direction of Na+(antiport) |
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Term
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Definition
active
vesicle forms around substance and is taken into cell. requires ATP
Phagocytosis takes in cells and solid particles; pinocytosis takes in molecules dissolved in liquid
receptor mediated- receptor needed by molecule to get through cell
Immune system cells called phagocytes ingest bacteria and cellular debris; most cells take in substances through pinocytosis |
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Term
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Definition
active
Secretory vesicles- materials are packaged in these, then the vesicle fuses with plasma membrane and releases its contents to the outside of the cell. ATP required
Proteins and other water soluble molecules are transported out of cells
Digestive enzymes, hormones, neuro-transmitters, and glandular secretions are transported, and cell waste products are eliminated |
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Term
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Definition
fluid in cytoplasm
it is a colloid and suspension |
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Term
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Definition
supports cell and holds the nucleus and organelles in plase
responsible for hanged in cell shape and the movement of cell organelles |
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Term
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Definition
| hollow tubes composed primarily of protein units called tubulin. provide support and are involved in cell division and transport of intracellular materials **component of spindle fibers, centrioles, cilia, and flagella |
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Term
| microfilaments/ actin filaments |
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Definition
| small fibrils that form bundles, sheets, or networks in the cytoplasm (spider web like). they provide structure to the cytoplasm and mechanical support for microvilli, support the plasma membrane, and define shape of cell. **changes in cell shape involve breakdown and reconstruction of microfilaments **responsible for muscle contraction |
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Term
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Definition
| protein fibers that provide strength to cells |
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Term
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Definition
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Term
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Definition
increase surface area of cell and facilitate absorption
DONT move
extension of plasma membrane |
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Term
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Definition
move materials over the surface of cells
doublets of parallel microtubules
they DO move
extension of plasma membrane |
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Term
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Definition
control center
site of DNA
membrane bound-NUCLEOPLASM
NUCLEOLUS- dense region with no membrane, subunits of ribosomes manufactured here
NUCLEAR ENVELOPE- composed of 2 membranes separated by a space.
NUCLEAR PORES- allow movement from nucleus to cytoplasm |
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Term
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Definition
| the chromosomes are dispersed throughout nucleus as chromatin during most of the cells life cycle |
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Term
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Definition
intermediate than can leave the nucleus UNLIKE DNA.
*dna functions through RNA |
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Term
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Definition
| a sequence of nucleotides in a DNA molecule that specifies an RNA molecule |
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Term
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Definition
- sites of protein synthesis
-each ribosome has a large and small subunit
-ribosomal RNA(made in nucleus) + proteins(made in cytoplasm)
- free ribosomes- produce proteins for use within the cell
-ribosomes attached to ER- produce proteins secreted out of cell |
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Term
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Definition
- a series of membranes distributed throughout the cytoplasm
-consists of broad, flat, interconnecting sacs and tubules
-interior part of sacs is called CISTERNAE
ROUGH ER- ribosomes, synthesizes proteins and transports them to the GA
SMOOTH ER- no ribosomes, manufactures lipids/carbs, detoxifies harmful chemicals, and stores calcium |
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Term
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Definition
-flattened membrane sacs(pancakes) containing CISTERNAE
-packaging and distribution center of proteins and lipids coming from the ER in transport vesicles
-adds carbs to proteins (glycoproteins)
-adds lipids to proteins (lipoproteins)
-secretory vesicles- pinch off from the golgi apparatus and then move to the surface of the cell and are excreted into the extracellular environment |
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Term
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Definition
membrane bound vesicles that form at the golgi apparatus
-contain hydrolytic enzymes that function in intracellular digestive systems |
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Term
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Definition
-membrane bound vesicle that serves as a site of LIPID AND AMINO ACID breakdown which produces hydrogen peroxide which is then also broken down
-cells important in detoxification have many peroxisomes |
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Term
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Definition
large protein complexes containing enzymes that break down and recycle other proteins within the cell
-no membrane |
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Term
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Definition
-provide energy for the cell
-power home
-atp synthesis
-double membrane
-inner membrane has foldings called CRISTAE
-MATRIX- substance in the middle of the two membranes |
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Term
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Definition
| specialized zone of cytoplasm near nucleus, microtubules formed here, involved in determining the cell shape and movement |
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Term
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Definition
the centrosome contains 2 centrioles
-each centriole composed of nine triplets of microtubules
- they influence the distribution of actin and intermediate filaments |
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Term
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Definition
| - before cell division the centrosome divides in two and each moves to one end of the cell. the microtubules from each centriole are called spindle fibers and extend out and facilitate in movement of chromosomes |
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Term
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Definition
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Term
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Definition
the production of RNA and or proteins from the information stored in DNA
-transcription
-translation |
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Term
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Definition
| making a copy of the gene or small part of info in DNA (mRNA) |
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Term
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Definition
| taking the copy of the gene (mRNA) and converting it to a protein at the ribosome |
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Term
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Definition
interphase
cell division (mitosis and cytokinesis)
-prophase
-metaphase
-anaphase
-telophase |
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Term
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Definition
preparation phase, most time spent in interphase, DNA is doubles and cell gets bigger in preparation
G1- phase between cell division, normal metabolic activity
S phase- replication of DNA
G2- preparation |
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Term
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Definition
| prophase- chromatin forms chromosomes, nuclear envelope disintegrates, spindles attach |
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Term
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Definition
| metaphase- spindles take chromosomes to equator and line them up |
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Term
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Definition
| anaphase- sister chromatids move to opposite ends via the spindles, centromeres divide, cleavage begins |
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Term
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Definition
| chromosomes are separated, 2 nuclear envelopes formed, spindle fibers disappear |
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Term
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Definition
| cytoplasm divides, two daughter cells formed |
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Term
| what is made in the nucleolus |
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Definition
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Term
| what does the smooth ER do?? |
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Definition
manufactures lipids and carbs
stores calcium
detoxifies harmful chemicals |
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Term
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Definition
synthesizes proteins
sends them to Golgi apparatus for excretion |
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Term
what does the golgi apparatus manufacture/package/ and distribute?
how does it modify them? |
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Definition
proteins and lipids
(came from ER in transport vesicles)
makes glycoproteins and lipoproteins
(carb+protein, or lipid+protein) |
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Term
| secretory vesicles come from which organelle? |
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Definition
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Term
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Definition
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