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136 Cards in this Set
- Front
- Back
THE CELL THEORY
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1-cell is the basic structural unit of life
2-activity of an organism depends on the individual cell and collective activities of its cells 3- biochemical activities are determined by number of specific subcellular structures 4- continuity of life has a cellular basis |
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3 PARTS OF HUMAN CELLS
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1- plasma membrane (semi permeable)
2- cytoplasm (inside the cell) 3- nucleus (DNA replication) |
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INTRACELLULAR
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inside the cell
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EXTRACELLULAR
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outside the cell
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PLASMA MEMBRANE
(3 parts) |
1- fluid mosaic model- lipid bilayer with proteins imbedded
2- hydrophilic head- attracts H2O 3- hydrophobic tail (make up interior of membrane) **plasma membrane plays a dynamic role in cellular activity. There are lots of metabolic processes and the membrane provide biological markers for cell-cell recognition **cholesterol helps stabilize membrane fluidity |
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GLYCOLIPIDS
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phospholipids with attached sugar groups
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FUNCTIONS OF PLASMA MEMBRANE
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transport (hydrophilic channel, hyrdolyze ATP to pump material)
enzymatic activity receptors for signal transduction (bonding site for specific chemical messengers, like hormones) intercellular joining cell to cell recognition structural support (for keeping proper shape and position) |
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INTEGRAL PROTEINS
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proteins that are firmly inserted in the lipid bilayer
**most protrude from both sides of the membrane as TRANSMEMBRANE PROTEINS |
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PERIPHERAL PROTEINS
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proteins that are loosely attached
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GLYCOCALYX
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carbohydrate rich area at the cell surface (glycolipids and glycoproteins); provides biological markers for cells to recognize each other and interact
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MICROVILLI
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finger-like extensions of the plasma membrane that increase cell surface area. found only in cells involved with absorption
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MEMBRANE JUNCTIONS (3)
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tight junction
desmosomes gap junction |
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TIGHT JUNCTION
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impermeable (watertight) junction of interlocking proteins surrounding the cell
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DESMOSOMES
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anchoring junctions
consists of internal protein plaque and external linker proteins |
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GAP JUNCTIONS
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"open junction" allows cellular communication and interaction due to connexons (hollow protein channels) that allow substances to pass between cells. These come together to form intercalated discs
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INTERSTITIAL FLUID
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derived from the blood; extracellular fluid
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SELECTIVELY PERMEABLE
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describes plasma membrane
allows only certain substances to pass through |
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PASSIVE PROCESSES
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doesn't require ATP
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DIFFUSION
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tendency for molecules or ions to disperse evenly
moves from HIGH to LOW concentration, forming concentration gradient (difference in concentration). Influenced by Molecule size and Temperature. |
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3 CATEGORIES OF DIFFUSION
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simple diffusion
facilitated diffusion osmosis |
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SIMPLE DIFFUSION
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lipid soluble substances diffusing directly through the lipid bi-layer. still uses concentration gradient (HI to LO) to move in a cell
only for NON-POLAR and LIPID SOLUBLE substances (ex/ O, CO2) |
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FACILITATED DIFFUSION
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large polar molecules like simple sugars
glucose and amino acids small lipid-insoluble solutes (aka water soluble) diffuse thru channel proteins. The solutes cant get through the lipid bilayer without help, so proteins create a channel to help them get thru. Still uses HI to LO concentration gradient but it needs a helping protein. piggy backing: binds to protein carrier and gets moved across |
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OSMOSIS
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diffusion of water across a semipermeable membrane
the solute (if any) dissolved in the water is left behind occurs when the concentration of water is different on opposite sides of a membrane |
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FILTRATION
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water diffusing through a membrane due to hydrostatic pressure (back-pressure)
forms a pressure gradient ex/ garden hose with small holes |
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ACTIVE PROCESSES (2)
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Transport powered by ATP
Active Process Vesicular Transport |
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SODIUM-POTASSIUM PUMP
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difference in concentration between NA and K within and outside the cell
forms a membrane potential |
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ENDOCYTOSIS
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particles moving within the cell
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EXOCYTOSIS
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particles moving outside the cell
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PHAGOCYTOSIS
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cellular eating
pseudopodia engulf solids and brings them into the cells interior |
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PINOCYTOSIS
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cellular drinking; aka fluid-phase-endocytosis / bulk phase endocytosis
plasma membrane infolds, bringing extracellular fluid and solutes into the interior of the cell |
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MEMBRANE POTENTIAL
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electrical energy caused by separation of 2 oppositely charged particles; or voltage across a membrane
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RESTING MEMBRANE POTENTIAL
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all resting body cells found in this state
results mostly from Na and K concentration gradients across the membrane due to: 1) differential permeability of the plasma membrane to Na and K 2) Na K pump |
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CAMs (cell adhesion molecules)
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glycoproteins that:
-anchor cells to the extracellular matrix and each other -assist in the movement of cells past one another -direct white blood cells to injured or infected areas -respond to tension at the cell surface |
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LIGANDS
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signaling chemicals that bind specifically to membrane receptors
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G-LINKED PROTEIN RECEPTORS
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the middleman responder
ligand binds to a receptor molecule receptor activates G-linked protein G linked protein stimulates an effector protein effector produces 2nd messenger enzymes trigger cell response |
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CELL LIFE CYCLE: 2 PHASES
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interphase
S-phase |
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INTERPHASE
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growth and replication of DNA
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S PHASE
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stage of interphase where DNA is replicated
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BEFORE A CELL CAN DIVIDE, WHAT MUST FIRST HAPPEN?
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DNA must be replicated
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ORDER OF DNA REPLICATION (5)
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1) DNA helicase untwists the helix
2) RNA primers form DNA polymerase 3, DNA polymerase 1, and DNA ligase 3) DNA polymerase 3 starts from primer, positions the strands and links them together 4)DNA polymerase 1 then replaces the primer 5)DNA Ligase splices short segments of DNA together |
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ROLE OF RNA (3)
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tRNA
mRNA rRNA |
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PROMOTER
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must be present for transcription to occur
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RNA POLYMERASE
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enzyme that oversees the synthesis of mRNA
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CODON
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codes for amino acids on mRNA
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TRANSLATION
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-nucleic acids are translated into the language of proteins
-occurs in cytoplasm tRNA comes and transfers amino acids and forms anticodon |
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APOPTOSIS
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programmed cell death
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GLYCOPROTEINS
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have attached carbohydrate chains
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OSMOLARITY
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total concentration of solute particles in a solution
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OSMOTIC PRESSURE
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pressure required to resist further water entry into a cell
in plant cells this creates internal pressure and stops net water movement animal cells shrink or swell in response to osmotic imbalances |
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TONICITY
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measure of the ability of a solution to change cell shape or tone by promoting water flow
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HYPERTONIC
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solution w higher concentrations of solutes than the concentration inside the cell
cell filling up with water |
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HYPOTONIC
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solution with lower concentrations of solute than what is inside the cell
water leaving a cell |
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ISOTONIC
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solution with same concentration of solutes as what is inside the cell
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ACTIVE PROCESS
1) SYMPORT SYSTEM |
2 substances are moved across a membrane in the same direction
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ACTIVE PROCESS
2) ANTIPORT SYSTEM |
2 substances are moved across a membrane in opposite directions
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ACTIVE PROCESS
3) SECONDARY ACTIVE TRANSPORT |
use of an exchange pump indirectly to drive the transport of other solutes
ex/ NA K pump |
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VESICULAR TRANSPORT
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transport of large particles and macromolecules across plasma membranes in membrane vessicles
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VESICULAR TRANSPORT
1) EXOCYTOSIS |
moves subtances from interior of cell to extracellular space
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VESICULAR TRANSPORT
2) ENDOCYTOSIS |
enables large particles and macromolecules to enter the cell (several varieties)
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RECEPTOR MEDIATED ENDOCYTOSIS
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uses receptors in clathrin-coated puts as the major mechanism for specific uptake of macromolecules
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ROLES OF MEMBRANE RECEPTORS
(PROTEINS AND GLYCOPROTEINS) |
Contact signaling
electrical signaling chemical signaling G protein linked receptors |
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CONTACT SIGNALING
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important in normal tissue development and immunity
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ELECTRICAL SIGNALING
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voltage-regulated "ion gates" in nerve and muscle tissue respong to voltage changes
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CHEMICAL SIGNALING
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signal chemicals (ligands) binding to membrane receptors
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G-PROTEIN LINKED RECEPTORS
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binding of ligand activates G protein, causing the release of a 2nd messenger (ex/ cyclic AMP)
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OPERATION OF A G-PROTEIN
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extracellular ligand (first messenger) binds to a specific membrane receptor
receptor protein activates G protein which relays message to an effector protein effector is enzyme whice produces 2nd messenger 2nd messenger activates kinase activated kinase triggers variety of cellular responses |
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DEOXYRIBONUCLEIC ACID (DNA)
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double stranded helical molecule found in nucleus of a cell
replicated itself before the cell divides provides instructions for protein synthesis |
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STRUCTURE OF DNA
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the nucleotide is composed of:
N-containing base pentose sugar phosphate group |
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4 NITROGEN BASES THAT MAKE NUCLEOTIDE STRUCTURE
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A adenine
G guamine C cytosine T thymine |
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CHROMATIN: DNA ORGANIZATION
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threadlike strands of DNA and Histones
arranged into units called nucleosomes condenses to form chromosomes when the nucleus starts to divide |
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DNA REPLICATION
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begins s-phase of interphase
DNA helices begin unwinding from the nucleosomes |
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HELICASE ENZYME / SEMICONSERVATIVE REPLICATION
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begins with replisome
untwists the double helix and exposes the complimentary strands each nucleotide strand serves as a template for building a new complementary strand entire process called semiconservative replication |
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REPLISOME
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formation of complex proteins which starts the process of DNA replication
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RNA PRIMERS
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short segments of RNA
formed by the replisome initiates DNA synthesis |
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DNA POLYMERASES
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continue from the primer to add complementary nucleotides to each template and replaces the RNA primer with DNA nucleotides
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DNA LEADING STRAND
DNA LAGGING STRAND |
leading strand is continuous strand of DNA that continues on in one direction
lagging strand is discontinuous and is the ending side of the leading strand |
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GENES
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segments of DNA carrying instructions for the polypeptide chain
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TRIPLETS
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groups of 3 nucleotide bases forming the genetic alphabet
code for the amino acids of a polypeptide |
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EXONS
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characteristics; coding regions of DNA that
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INTRONS
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junk DNA; matching/non coding triplets
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ROLE OF mRNA
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carries genetic information from DNA to the ribosomes in the cytoplasm
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ROLE OF rRNA
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structural component of ribosomes
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TRANSCRIPTION
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occurs inside nucleus
1st process of re-writing DNA to RNA form in order to bring to ribosomes in the cytoplasm transfer of information occurs in nucleus complimentary copy of DNA is made as mRNA |
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URACIL (U)
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base in RNA that takes the place of T (thymine) in DNA strand
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PROMOTER SEQUENCE
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signals the start of RNA synthesis
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TRANSCRIPTION FACTORS
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activate the gene to be transcribed and bind to the promoter
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ROLES OF RNA POLYMERASE
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oversees synthesis of mRNA
unwinds DNA and adds proper RNA nucleotides transcribes DNA triplets into mRNA codons (3 base sequences on RNA) |
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EDITING RNA
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1st copy (pre-mRNA) has coding exons and non coding introns; the same regions as found in DNA
spliceosomes produce functional RNA |
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SPLICEOSOMES
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RNA- protein complexes
remove introns from the pre-mRNA to produce functional mRNA |
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PROTEIN SYNTHESIS: TRANSLATION
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1) binding of specific aminoacyl-tRNA to complimentary mRNA codon at the "A-Site" (aminoacyl-tRNA always moves into the A-Site
2) new amino acid is added to the polypeptide chain as a peptide bond, formed between the amino acids 3) ribosome moves one codon to the right, and the unchanged tRNA moves from P site to E site 4) tRNA is released from the E-site; ribosome is ready for another cycle |
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RIBOSOMES
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rRNA binds base pairs; turns into mRNA when it leaves the nucleus
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mRNA CODONS
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3 base sequences on mRNA copied from DNA triplets
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TRANSFER RNAs (tRNAs)
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bind amino acids and pair with codons of mRNA at the ribosome
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ANTICODONS
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3-base sequences on tRNA
pair with codons on mRNA amino acids brought to the ribosome by tRNA form a polypeptide chain |
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BONUS: BE ABLE TO LIST TRIPLETS FROM DNA TO COMP. DNA, mRNA, tRNA, AND FINAL POLYPEPTIDE CHAIN
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DNA to complimentary DNA is just opposite of AGTC
mRNA is the same as original DNA strand, just change the T to U because its the RNA code tRNA is coded off of the mRNA, its the anticodon sequence (opposite of mRNA sequence) look at the chart and the mRNA strand will code for an exact polypeptide chain |
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INFORMATION TRANSFER AND THE GENETIC CODE
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DNA triplets are transcribed into mRNA codons by RNA polymerase
codons base pair with tRNA anticodons at the ribosomes amino acids are peptide bonded at the ribosomes to form polypeptide chains (protein) |
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POLYPEPTIDE CHAINS (PROTEINS)
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amino acids peptide bonded at the ribosomes
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THE GENETIC CODE
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RNA codons code for amino acids according to this genetic code
some codos serve as start and stop signals for translation redundancy in the genetic code means many mutations are inconsequential |
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CODON CHART
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Start: AUG (MET)
Stop: UAA, UGA, UAG |
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SIGNAL MECHANISM OF PROTEIN SYNTHESIS
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mRNA / ribosome complex is directed to rough ER by a signal - recognition particle (SRP)
polypeptide grows into rough ER protein is released into the rough ER and folds into a 3D conformation protein is enclosed in a transport vessicle and moves toward the golgi apparatus |
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DEVELOPMENTAL ASPECTS OF CELLS
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all cells of the body contain the same DNA but develop into specialized cells of the body
genes of specific cells are turned on or of determining the proteins that are made in that cell cell differentiation |
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CELL DIFFERENTIATION
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development of specific and distinctive features in cells
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CELL AGING: WEAR AND TEAR THEORY
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attributes aging to chemical damage and formation of free radicals that have cumulative effects throughout cell life
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CELL AGING: GENETIC THEORY
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attributes aging to cessation of mitosis that is programmed into our genes
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CELL AGING: TELOMERES
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ends of chromosomes which are eroded with each division, resulting in the end of cell division
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GENERAL TYPES OF TISSUE
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epithelial
connective tissue muscular nervous |
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2 FORMS OF EPITHELIAL TISSUE
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covering/lining epithelium
glandular epithelia |
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FUNCTION CHARACTERISTICS OF EPITHELIAL TISSUE
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protection, absorption, secretion, excretion, filtration, sensory reception
CHARACTERISTICS cellularity special contacts polarity support by connective tissue vascularity regeneration |
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CELLULARITY
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composed almost entirely of cells
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SPECIAL CONTACTS
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held together by tight junctions and desmosomes
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POLARITY
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apical and basal surfaces
(apex: above free surface) (basal: bottom; in basement membrane) |
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WHAT FORMS A BASEMENT MEMBRANE?
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basal-connective tissues
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VASCULARITY
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avascular; simple diffusion
innervated; controlled by and communicates with nervous system |
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REGENERATION
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rapidly replaces cells lost by cell division
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TYPES OF GLANDULAR EPITHELIA
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enodcrine and exocrine glands
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EXOCRINE GLANDS
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secretes hormones outside the body or onto body surfaces
ex/ mucous, sweat, oil, salivary glands (goblet cells also) |
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ENDOCRINE GLANDS
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any gland which secretes hormones in the bloodstream
ductless glands produce hormones secretions enter extracellular space then the blood to affect other organs |
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EXOCRINE GLANDS: MODES OF SECRETION
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merocrine glands
holocrine glands |
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MEROCRINE GLANDS
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products are secreted by exocytosis
(ex/ sweat, salivary glands) |
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HOLOCRINE GLANDS
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products are secreted by the rupture of gland cells, and all of its contents spill outside of the cell
(ex/ sebaceous glands) |
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CUTANEOUS MEMBRANE
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skin (stratified squamos epithelium)
= protective role any stratified epethelial tissue is doing some sort of protective role |
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MUCOUS MEMBRANE
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mucosae
inside lining of lungs, trachea, digestive, and respiratory tracts (all of these are open cavities to the outside world) |
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SEROUS MEMBRANE
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found in ventral body cavity
make serous fluid (which protects organs by adding extra cushion by surrounding them with fluid) acts like a barrier (ex/ pleura, pericardium, peritonium) |
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CONNECTIVE TISSUES
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have MESENCHYME as their common tissue of origin
(varying degrees of blood supply for each type) non-living extracellular matrix, consisting of ground substance and fibers ex/ areolar, adipose, cartilage, (hyaline, elast, fibro) bone, blood, dense connective tissue (regular/irregular) |
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GROUND SUBSTANCE
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unstructured material that fills space between cells
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FIBERS
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collagen (tensile strength)
elastic reticular (thin branching collagen) |
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NERVOUS TISSUE
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nervous system composed of brain, spinal cord, nerves
have neurons with long cellular processed and neuroglia (supportive cells) transmits electrical signals between brain, spinal cord, and nerves |
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MUSCLE TISSUE (3)
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contains actin and myosin (myofilaments) responsible for muscle contraction
3 types: skeletal, cardiac, smooth |
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TISSUE REPAIR
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inflammation
organization regeneration / fibrosis |
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INFLAMMATION
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caused by tissue damage
redness, heat, swelling, pain blood clot formation |
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ORGANIZATION
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restored blood supply
blood clot is replaced with formation of granulation tissue |
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REGENERATION / FIBROSIS
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surface epithelium regenerates
fibrous tissue matures from granulation tissue |
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DEVELOPMENTAL ASPECTS
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primary germ layers: ectoderm, mesoderm, endoderm
3 layers of cells form during embryonic development, which specializes to form 4 primary tissues epithelial tissues arise from all 3 germ layers |
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ECTODERM
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creates nervous tissue
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MESODERM
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creates muscle and connective tissue
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ENDODERM
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creates mucosae
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