Cell Flashcards
Contains DNA, Histones & Chromosomes; has nucleolus
Nucleus
Powerhouse of the cell
Mitochondria
Involve in detoxification, lipid synthesis, lipid soluble substances; water-soluble substances
Agranular or smooth endoplasmic reticulum (SER)
For synthesis of proteins bound for the cell membrane, lysosomes, outside of the cell
Ribosomes of the rough endoplasmic reticulum (RER)
For synthesis of proteins bound for the cytoplasm and mitochondria
Free-floating Ribosomes
For packaging, molecular tagging, and synthesis of hyaluronic acid & chondroitin sulfate
Golgi Apparatus
Replenishes the cell membrane; may contain proenzymes, NT’s
Secretory Vesicles
For regression of tissues and Autolysis; Suicide bags of the cells
Lysosomes
Degrade membrane-associated proteins; not membrane-bound
Proteosome
Contains oxidases, catalases; for detoxification
Peroxisome
Site of transcription and processing of rRNA
Nucleolus
Location of Electron Transport Chain
Inner Mitochondrial Membrane (Oxidative Phosphorylation)
Unique about the mitochondria
Contains mitochondrial DNA that is maternally-derived and does not follow genetic code
RER & SER are abundant in which organ?
Liver
Subunits of Ribosomes
Prokaryotes: 30s, 50sEukaryotes: 40s, 60s
Specialized SER in skeletal muscle
Sarcoplasmic Reticulum
Specialized SER in Neurons
Nissl Substance
Only substance modified in the RER and not in Golgi Apparatus
Collagen
Added to lysosome-bound proteins by the golgi apparatus
Mannose-6-phosphate
Lysosomes come from what organelle?
Golgi apparatus
Peroxisomes come from what organelle?
Smooth Endoplasmic Reticulum
Wear-and-tear pigment that accumulates in lysosomes?
Lipofuscin
Motor protein causing transport from center of the cell to the periphery
Kinesin
Motor protein causing transport from periphery of the cell to the center
Dynein
Which anti-tumor drugs target the microtubules during mitosis?
Vincristine, Taxol
Disease with Dynein missing in cilia and flagella
Kartagener’s Syndrome (Situs Inversus, Bronchiectasis, Infertility)
What is the explanation for Situs Inversus in Kartagener’s Syndrome?
Defective primary cilia
Disk-shaped; for firm intercellular adhesions
Macula densa (Desmosomes)
Ring-shaped; increases surface area for contact
Zonula adherens (Fascia adherens)
Reticular pattern; divides cell into apical and basolateral side
Zonula occludens (Tight junctions)
For intercellular communication
Gap junctions
Functional unit of Gap junctions
Connexon
Movement of substances in both the apical and basolateral side
Transcellular Transport
Movement of substances between cells through tight junctions
Paracellular Transport
Guardian of the cell that divides the body into ECF and ICF compartments
Cell membrane
Mainly determines membrane fluidity and permeability to water soluble structure
Cholesterol
Anchors protein to outer leaflet
Glycolipid: Glycosylphosphatidylinositol (GPI)
Which disease involves a mutation in a gene of Chromosome 7 that encodes for an ABC transporter called CFTR?
Cystic Fibrosis
Endocytosis: For proteins; requires ATP and extracellular calcium
Pinocytosis
Endocytosis: usually receptor-mediated; usually by WBC’s and macrophages; for larger substances like bacteria, cell debris, dead cell
Phagocytosis
Secretion of Hormones, Neurotransmitters from intracellular vesicles (mediated by SNARE proteins); results in excretion of Residual Body
Exocytosis
Predominant Cation in ECF
Na+ (Sodium)
Predominant Anion in ECF
Cl- (Chloride)
Predominant Cation in ICF
K+ (Potassium)
Predominant Anion in ICF
PO4- (Phosphate)
In each compartment, total number of Cations should EQUAL total number of Anions
Principle of Macroscopic Electroneutrality
“Where Sodium goes, Water follows…”
90% of the solutes in the ECF is Na+ (Sodium) making it a reasonable indicator for osmolarity
Indicator molecule for TBW
Deuterium Oxide, Antipyrine
Indicator molecule for ECF
Inulin, Mannitol
Indicator molecule for Plasma
124I-Labeled Albumin
Osmoles per kilogram of water; Independent of Temperature
Osmolality
Osmoles per liter of water; varies with Temperature
Osmolarity
Clinical estimate of plasma osmolality can be obtained using:
Sodium concentrationGlucose concentrationUrea concentration
Poisoning that increases Osmolar Gap
Alcohol intoxication and Ethylene Glycol poisoning
Diffusion of water from a solution of low solute concentration to a solution of high solute concentration
Osmosis
Driving force of Osmosis that is dependent on number of molecules
Osmotic Pressure
Uses impermeate solutes; can change cell volume
Isotonic, Hypertonic, Hypotonic
Uses permeate solutes; can change cell volume only transiently
Isoosmotic, Hyperosmotic, Hypoosmotic
Will attract water to itself
Hypertonic solution
Will donate water to opposite compartment
Hypotonic solution
Example of impermeate solute
Glucose (effective osmole)
Example of permeate solute
Urea (ineffective osmole)
Effective osmole used in the treatment of brain edema
Mannitol
Effect of permeate solutes on osmotic gradient
Decreases osmotic gradient
Osmotic pressure from large molecules
Oncotic Pressure
Weight of the volume of a solution divided by weight of equal volume of distilled (pure) water
Specific gravity
Number between zero and one that describes the ease with which a solute permeates a membrane
Reflection Coefficient / Osmotic Coefficient
Solute is impermeable
Reflection Coefficient = 1
Solute is neither permeable nor impermeable
Reflection Coefficient = between 0 to 1
Solute is permeable
Reflection Coefficient = 0
Isotonic NaCl infusion; Gain of H2O and Na; Increase in ECF volume
Isoosmotic volume expansion
Diarrhea; Loss of H2O and Na; Decrease in ECF volume
Isoosmotic volume contraction
High NaCl intake, Conn’s syndrome; Gain of Na; Increase in ECF osmolarity and volume; Decrease ICF volume
Hyperosmotic volume expansion
Sweating, Fever, Diabetes Insipidus; Loss of H2O; Increase in ECF osmolarity; Decrease in ECF and ICF volume
Hyperosmotic volume contraction
SIADH; Gain of H2O; Decrease in ECF osmolarity; Increase in ECF and ICF volume
Hypoosmotic volume expansion
Adrenal insufficiency, Diuretics overuse; Loss of Na; Decrease in ECF osmolarity and volume; Increase in ICF volume
Hypoosmotic volume contraction
0.9% NaCl (PNSS) or Lactated Ringers (LR); Increases ECF volume exclusively
Isotonic Solution
0.45% NaCl or 5% Dextrose in water (D5W); Increases both ECF and ICF volume
Hypotonic Solution
3% NaCl or 5% NaCl; Increases ECF volume and Decreases ICF volume
Hypertonic Solution
Passive, Downhill transport; Not carrier-mediated, No metabolic energy used, Not dependent on Na+ gradient
Simple Diffusion
Passive, Downhill transport; Carrier-mediated, No metabolic energy used, Not dependent on Na+ gradient
Facilitated Diffusion
Active, Uphill transport; Carrier-mediated, With metabolic energy used (direct), Not dependent on Na+ gradient
Primary Active Transport
Secondary Active; Carrier-mediated, With metabolic energy used (indirect), Dependent on Na+ gradient (solutes move in same direction as Na+ across cell membrane)
Co-transport
Secondary Active; Carrier-mediated, With metabolic energy used (indirect), Dependent on Na+ gradient (solutes move in opposite direction as Na+ across cell membrane)
Counter-transport
Secondary Active Transport indirectly relies on:
Na-K-ATPase pump
Saturation of Active Transport
Tm occurs once all transporters are used
Stereospecificity of Active Transport
Recognizes “D” or “L” forms
Competition of Active Transport
Chemically-related solutes may compete
Which is faster at low solute concentration: Facilitated or Simple?
Facilitated
Which is faster at high solute concentration: Facilitated or Simple?
Simple
In Na-K-ATPase pump, how many Na+ goes out?
3
In Na-K-ATPase pump, how many K+ goes in?
2
Transport Mechanism of Oxygen, Nitrogen, CO2, Alcohol, Lipid Hormones, Anesthetic drugs
Simple Diffusion
Transport Mechanism of D-glucose transport to the muscles and adipose, Amino Acid transport
Facilitated Diffusion
Transport Mechanism of Na-K-ATPase pump, Ca-ATPase pump in cell membrane and SR, H-K ATPase pump in stomach, H- ATPase pump in intercalated cell of kidney, Multi-drug resistance transporters
Primary Active Transport
Transport Mechanism of SGLT-1 in small intestine, SGLT-2 in the PCT, Na-K-2Cl in ascending tubule, Na-Ca exchange in almost all cells, Na-H exchange in PCT
Secondary Active Transport
Ca-ATPase pump in the cell membrane
Plasma membrane associated Ca ATPase (PMCA)
Ca-ATPase pump in sarcoplasmic reticulum an endoplasmic reticulum
Sarcoplasmic and ER Ca-ATPase (SERCA)
Functions of Na-K-ATPase pump
Prevents cellular swelling; contributes to RMP
Functional subunit by Na-K-ATPase pump inhibited by Cardiac Glycosides
Alpha subunit
In all epithelial cells, Na-K-ATPase pump is found in the basolateral side EXCEPT:
Choroid Plexus
Why do RBC’s swell when chilled?
Decrease ATP synthesis (Decrease activity of Na-K-ATPase pump)
Receptors for Fat-soluble substances; Binding to nuclear or cytoplasmic receptors that causes transcription of genes
Intracellular Receptors
Membrane Receptor: Transduces chemical signal into electrical signal
Ion-channel linked Receptor
Membrane Receptor: Activates cGMP phosphodiesterase; Decreases cGMP; Closes cGMP-dependent ion channels
G-Protein Coupled Receptor with Alpha-t subunit (Transducin)
Membrane Receptor: Activated by Guanine Nucleotide Exchange Factors (GEFs); Inactivated by GTPase-accelerating proteins (GAPS), RGS proteins (regulation of G Protein signaling)
G-Protein Coupled Receptor (GTP-activated)
Membrane Receptor: Activates Adenylyl cyclase (converts ATP to cAMP); Activates Protein Kinase A (PKA)
G-Protein Coupled Receptor with Alpha-s and Alpha-i subunit
Membrane Receptor: Phospholipase C (PLC) ➡️ PIP2 ➡️ PIP2 splits into InsP3 or IP3 (releases Calcium from ER) and DAG (activates Protein Kinase C)
G-Protein Coupled Receptor with Alpha-q subunit
Catalytic Receptor: Converts GTP to cGMP; Activates Protein Kinase G; Phosphorylates Proteins (eg: ANP, NO)
Receptor Guanylyl Cyclases
Catalytic Receptor: Attaches to Type 1 subunit; Phosphorylates Serine/Threonine residues on Type 2 subunit; Activates Effectors (eg: THF-Beta)
Receptor Serine/Threonine Kinases
Catalytic Receptor: eg: NGF, EGF, PDGF, IGF-1, Insulin
Receptor Tyrosine Kinase
Catalytic Receptor: No intrinsic Tyrosine Kinase Activity; Associated with proteins that have Tyrosine Kinase Activity, including Tyrosine Kinases of Src Family and Janus Family (JAK) (eg: EPO)
Tyrosine-associated Kinase Receptors
Cytosolic fragment released to the nucleus which causes transcription of genes (eg: Sterol Regulatory Element-Binding Protein (SREB) of the ER - promotes Cholesterol Synthesis)
Regulated Intramembrane Proteolysis
Regulated Intramembrane Proteolysis (RIP) of amyloid B-protein precursor causes accumulation of amyloid B-protein in which disease?
Alzeimer’s Disease