I - Cell Physiology Flashcards
Basic living unit of the body
Cell
Cells that always replicate
Labile Cells
Cells that are inactive but can replicate when needed
Quiescent/Stable Cells
Cell that cannot replicate
Permanent Cells
Substances that make up the entire cell
Protoplasm
Components of the Protoplasm
water (70-80%), proteins (10-20%), lipids(2%), ions, carbohydrates
The Cell: Contains DNA, histones & chromosomes, has nucleoli
Nucleus
The Cell: Powerhouse of the cell
Mitochondria
The Cell: Involved in detoxification, lipid synthesis, converting lipid-soluble substances to water-soluble substances
Agranular/Smooth Endoplasmic Reticulum
The Cell: For synthesis of proteins bound for the cell membrane, lysosomes, outside of the cell
Rough Endoplasmic Reticulum
The Cell: For synthesis of proteins bound for the cytoplasm and mitochondria
Free-floating Ribosomes
The Cell: For packaging,molecular tagging and synthesis of hyaluronic acid and chondroitin sulfate
Golgi Apparatus
The Cell: Contains proenzymes, neurotransmittters and replenishes cell membrane components
Secretory Vesicles
The Cell: For regression of tissues and autolysis, suicide bags of the cell, destroys foreign bodies
Lysosomes
The Cell: Degrades membrane-associated proteins, not membrane-bound
Proteosomes
The Cell: Contains oxidases, catalases, helps in lipid synthesis and detoxification
Peroxisomes
Processes that happen both in the cytoplasm and the mitochondria
Heme synthesis, Urea cycle, Gluconeogenesis
Face of the golgi apparatus that accepts inactive proteins
Cis Face - convex
Face of the golgi apparatus that releases mature proteins
Trans Face - concave
Site of transcription and processing of rRNA
nucleolus
Contains its own DNA that is maternally derived and does not follow the genetic code
mitochondria
Exclusively Mitochondrial Processes
β-oxidation, Krebs Cycle
RER and SER are abundant in the
liver - other organelles are also increased
What are the components of prokaryotic ribosomes?
30s + 50s = 70s
What are the components of eukaryotic ribosomes?
40s + 60s = 80s
Specialized SER in the skeletal muscle
sarcoplasmic reticulum
Specialized SER in the neuron
Nissl substance
The only substance modified in the RER and not in the golgi apparatus
collagen
What is added to lysosome-bound proteins by the golgi apparatus?
mannose 6-phosphate (M6P)
Lysosomes come from which organelle?
golgi apparatus
Peroxisomes come from which organelle?
SER
Wear-and-tear pigment that accumulates in lysosomes
lipofuscin
Microvilli, locomotion of macrophages, muscles, zonula adherens, zonula occludens
Actin/Microfilaments
Keratin (epithelial cells), neurofilaments (neurons), desmosomes, hemidesmosomes
Intermediate Filaments
Flagella, cilia, centrioles, mitotic spindles, intracellular vesicles
Microtubules
Motor protein causing transport of substances from the center of the cell to the periphery
Kinesin
Motor protein causing transport of substances from the periphery to the center of the cell
Dynein
Direction of kinesin transport
center of the cell → periphery
Direction of dynein transport
periphery → center of the cell
Disease where cilia and flagella are missing dynein
Kartagener’s Syndrome
Kartagener’s Syndrome: Findings
situs inversus, bronchiectasis, infertility
Causes situs inversus in Kartagener’s Syndrome
defective primary cilia
Locomotion: WBCs, fibroblasts, germinal cells of the skin, fertilized embryo
amoeboid movement
Crawling movement in response to a chemotactic substance
amoeboid movement
Locomotion: respiratory airways, fallopian tubes
ciliary movement
Back-and-forth whip-like movement
ciliary movement
Locomotion: sperm
flagellar movement
Quasi-sinusoidal propeller-like movement
flagellar movement
Junctional Complexes: disk-shaped, for firm/tight intercellular adhesions
macula adherens (desmosomes)
Desmosomes (macula adherens) are found in
epithelium
Junctional Complexes: ring-shaped, increases surface area for contact
zonula adherens (fascia adherens)
Zonula adherens (fascia adherens) are found in
intercalated disks of cardiac muscles
Junctional Complexes: reticular patter, divides cells into apical and basolateral sides
zonula occludens (tight junctions)
Leaky zonula occludens (tight junctions) are found in
proximal convoluted tubule, jejunum
Tight zonula occludens (tight junctions) are found in
collecting ducts, terminal colon, BBB
Junctional Complexes: for intercellular communication
gap junctions
Gap junctions are found in
cardiac muscles, unitary smooth muscles (syncytium)
The functional unit of the gap junction
connexon
Movement of substances through the apical and basolateral side
transcellular transport
Movement of substances of between cells through tight junctions
paracellular transport
The tight junction is found near the _____ side.
apical side
Components of the Cell Membrane
proteins (55%), phospholipids (25%), cholesterol (13%), other lipids (4%), carbohydrates (3%)
Most important part of the cell membrane, determines fluidity and permeability
cholesterol
Glycolipid that anchors proteins to the outer leaflet
glycosylphosphatidylinositol (GPI)
Cell Membrane Proteins: has tight attachment using hydrophobic interactions
integral proteins
Cell Membrane Proteins: needs detergent to be removed
integral proteins
Cell Membrane Proteins: spans the entire thickness of the cell membrane
integral proteins
Cell Membrane Proteins: has loose attachment using electrostatic interactions
peripheral proteins
Cell Membrane Proteins: found on the inner or outer leaflet
peripheral proteins
Cell Membrane Transporters: number or permeability is variable
water channels/aquaporins (AQPs)
Cell Membrane Transporters: channels for Na, CA, K, CL
ion channels
Cell Membrane Transporters: can be uniport, symport or antiport
solute carriers
Cell Membrane Transporters: uses ATP for transport
ATP-dependent
ATP-Dependent Transporters: Na-K-ATPase
ATPase ion transporters
ATP-Dependent Transporters: Multi-drug Resistance Protein
ATP-Binding Cassette (ABC) transporters
Which disease involves a mutation in a gene of chromosome 7 that encodes for an ABC transporter called CFTR?
Cystic Fibrosis
Endocytosis: cell-drinking, for proteins, requires ATP and extracellular Ca
pinocytosis
Endocytosis: cell-eating, for large substances, exhibited by WBCs and macrophages, usually receptor-mediated
phagocytosis
Secretion of hormones and neurotransmitters from intracellular vesicles
exocytosis
Exocytosis is mediated by
SNARE proteins
Total Body Water: ___ of body weight
60% of body weight
Babies are ___ water.
75%
Total Body Water: % ICF
40% of body weight (2/3 of TBW)
Total Body Water: % ECF (internal environment/milieu intérieur)
20% of body weight (1/3 of TBW)
Total Body Water: Transcellular Fluid
1 L
Total Body Water: % Plasma
5% of body weight (1/4 of ECF)
Total Body Water: % Interstitial Fluid
20% of body weight (3/4 of ECF)
Predominant cation in the ECF
Na+
Predominant cation in the ICF
K+
Predominant anion in the ECF
Cl-
Predominant anion in the ICF
PO4-
In each compartment, total number of cations should equal total number of anions.
Macroscopic Electroneutrality Principle
Macroscopic Electroneutrality Principle
In each compartment, total number of cations should equal total number of anions.
In _____ compartment, total number of _____ should equal total number of _____.
each, cations, anions
What is the basis for saying”where Na goes, water follows”?
90% of solutes in the ECF is Na+ making it a reasonable indicator of osmolarity
What are the indicator molecules for TBW?
deuterium oxide, antipyrine
What are the indicator molecules for ECF?
inulin, mannitol
What are the indicator molecule for plasma?
124 I-labeled albumin
Units for Concentration: osmoles per kg of water
osmolality
Units for Concentration: osmoles per L of water
osmolarity
Units for Concentration: independent of temperature
osmolality
Units for Concentration: varies with temperature
osmolarity
Plasma Osmolarity mOsm/L =
2 x Na+ mEq/L + (glucose mg/dL/18) + (BUN mg/dL/2.8) [+ (ethanol mg/dL/4.6)]
Osmolar Gap =
measured osmolarity - estimated osmolarity
Osmolar gap _____ in alcohol intoxication and ethylene glycol poisoning.
increases
Movement of water from an area of low concentration to high concentration across a semi-permeable membrane
osmosis
_____ is the driving force of osmosis and is dependent on the _____ of molecules, not the mass, chemical nature or size.
Osmotic pressure, number of molecules
Osmosis: impermeant solute
glucose - effective osmole
Osmosis: permeant solute
urea - ineffective osmole
Osmosis: effective osmole used in treatment of brain edema
mannitol
Osmosis: osmotic pressure from large molecules (proteins)
oncotic pressure
Osmosis: 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/Osmotic Coefficient
Reflection/Osmotic Coefficient
molecules returned/molecules sent
No solute penetration, Reflection Coefficient =
Reflection Coefficient = 1
Some solute penetration, Reflection Coefficient is
0 < Reflection Coefficient < 1
Complete solute penetration, Reflection Coefficient =
Reflection Coefficient = 0
Transport Mechanisms: passive, not carrier-mediated
Simple Diffusion
Transport Mechanisms: passive, carrier-mediated
Facilitated Diffusion
Transport Mechanisms: active (ATP), carrier-mediated
Primary Active Diffusion
Transport Mechanisms: active (Na+ gradient), carrier-mediated
Secondary Active Transport
Transport Mechanisms: small non-polar molecules, gases
Simple Diffusion
Transport Mechanisms: GLUT
Facilitated Diffusion
Transport Mechanisms: Na-K-ATPase, Proton Pump (H+-K+)
Primary Active Diffusion
Transport Mechanisms: Na-K-2Cl Pump, SGLT 1 in SI, SGLT 2 in PCT
Secondary Active Transport
The secndary active transport mechanism relise on the Na+ gradient created by the
Na-K-ATPase Pump
Characteristics of Carrier-Mediated Transport
Saturation - Tm occurs once all transporters are used, Stereospecificity - recognized D or L forms, Competition - chemically-related structures may compete
At low solute concentration, _____ diffusion is faster than _____ diffusion.
facilitated > simple
At high solute concentration, _____ diffusion is faster than _____ diffusion
simple > facilitated
Transport Mechanisms: Ca-ATPase pump in the cell membrane
PMCA
Transport Mechanisms: Ca-ATPase pump in the sarcoplasmic reticulum and endoplasmic reticulum
SERCA
Transport Mechanisms: Functions of the Na-K-ATPase pump
prevents cellular swelling, contributes to resting membrane potential (RMP)
Transport Mechanisms: Functional subunit of the Na-K-ATPase pump inhibited by cardiac glycosides
alpha subunit
Transport Mechanisms: In all epithelial cells, Na-K-ATPase pump is found on the basolateral side except:
choroid plexus
Transport Mechanisms: Why do RBCs swell when chilled?
decreased ATP synthesis → decrease Na-K-ATPase pump activity