Patho Chap 1 Flashcards
Prokaryote
Larger cells with organelles and a nucleus
Eukaryote
Smaller, simpler cells without organelles or a nucleus
Ribosomes
RNA-protein complexes synthesized in the nucleolus. Main function is to provide sites for cellular protein synthesis
Rough ER
Contains ribosomes. Responsible for much of the cells protein synthesis and folding
Smooth ER
No ribosomes. Involved with steroid synthesis required to remove toxins from the cell
Golgi Apparatus
Processing and packaging of proteins from ER for transport
Lysosomes
Intracellular digestive enzymes produced in the Golgi Complex.
Primary Lysosomes
Merge with vacuoles
Secondary Lysosomes
Pump H+ into interior to maintain acidic pH, activate hydrolytic enzymes
Peroxisomes
Membrane bound organelles that contain oxidative enzymes. Detoxify waste and degrade long-chain fatty acids.
Mitochondria
Organells responsible for cellular respiration and energy production. Catabolism- releases energy from large molecule breakdown. Anabolism- uses energy to synthesize glycogen, proteins and lipids
Vaults
Octagonal organells thought to act simmilarly to ribosomes in transporting RNA
Glycolosis
Splitting of glucose. Produces a net of 2 moulecules of ATP per Glucose melecule split through Oxidation
Oxidative Phosphorilization DEF
Occurs in the mitochondrion. Is the mechanism by which energy from carbs, fats and proteins is transferred into ATP
Cori Cycle
lactate produced by anaerobic glycolysis in the muscles moves to the liver and is converted to glucose, which then returns to the muscles and is metabolized back to lactate
Cytoskeleton
ovement.Maintains cell shape and org. Permits
Microtubules
Provide strength, involved in cellular division, faclitate conduction of AP’s
Plasma Membrane
controls composition of the compartment, allows lipid-soluble molecules to diffuse through the membrane, provides structural integrity
3 methods of Chemical Signaling
- Form Gap Junctions
- Display plasma membrane-bound signaling receptors
- Secrete chemicals that signal cells
Hormonal Signaling
Hormones travel to target cell through blood or lymph
Neurohormonal signaling
Hormones released into the blood by neurosecretory neurons
Paracrine Signaling
Chemical mediators secreted, act on near-by cells
Autocrine Signaling
Signaling molecules act back on the cell origin
Extracellular messengers
Convey instructions to the cell’s interior (transfer, amplify, distribute and modulate)
First Messenger
Ligand bonds to receptor on the plasma membrane
emical deformation of the channel
- Binding of ligand to membrane receptor, 2. Changes in electrical current in plasma membrane, 3.
Second Messengers
FM binds to receptors, –>triggers production of 2nd messenger –> Uses G Protein (could also be cAMP or Ca2+)
Cellular Respiration Phase 1
Digestion
Cellular Respiration Phase 2
(anerobic) Glycolosis –> pyruvic acid (pyruvate)
Cellular Respiration Phase 3
- (aerobic) Citric Acid Cycle –>NADH and FADH2 2. Oxidative Phosphorilization –> ATP and H20
Glycolosis Pathway
Glucose + 2 NAD + 2 APD + Pi –> 2 pyruvic acid + 2 NADH and 2 ATP
Krebs Cycle Products
1 GTP, 3 NADH and 1 FADH2 then NADH and FADH2 –> electron transport cycle
Oxidative Phosphorilation FUNC.
ETC pulls electron pairs for NADH and FADH2 ADP + Pi –> ATP and O2 + 4e + 4H –> 2 H2O
Direct Phosphorylation net ATP
2 ATP
Oxidative Phosphoylation net ATP
26 ATP (2.5 from each NADH and 1.5 from each FADH2)
Cell Membrane is Selectivly Permeable to
- Non-polar molecules (O2) 2. Lipid Soluble molecules 3. Small suluble covalent bonds (CO2) 4. H20
Cell Membrane is Impermeable to
- Large polar molecules 2. Charged Ions
Passive Transport (diffusion) depends on
- Magnitude of concentration gradient 2. Electrical potential across the membrane 3. Permeability of the membrane 4. Temperature 5. Surface area of the membrane.
Plasma Osmolality
280-294 mOsm/ kg
Isotonic
Equal tension to plasma –> RBC’s will not +/- H20
Hypotonic
Osmotically active solutes in a lower osmolality than cell –> RBC’s will hemolyse
Hypertonic
Osmotically active solutes in a higher osmolality than cell –> RBC’s will crenate
Characteristics of Carrier-Mediated Transport carriers
- Specificity 2. Competition 3. Saturation 4. Ehibit Tm
Primary Active Transport
ATP directly required for the function of the carriers
Secondary Active Transport
Energy needed in some part of the transport process.
Endocytosis
Invagination of the cell membrane to bring substances into the cell
Pinocytosis
Continuall ingestion of fluids, often used interchangably with endocytosis
Phagocytosis
Large molecules are engulfed so that they can by destroyed by Lysosomes
Resting Membrane Potential
All cells are electically polarized (inside more - than outside)
Permeability of the cell membrane
a. 80% electrochemical gradients of Na+ and K+ b. 20% Na+/K+ ATPase pump
Excitability/ Irritability
Ability to produce and conduct electrical impulses
K Resting Potential Intracellular
150 mEq/L
K Resting Potential Extracellular
5 mEq/ L
Na Resting Potential Intracellular
14 mEq/L
Na Resting Potential Extracellular
140 mEq/L
Threshold
when depolarization reaches the threshold an AP occurs
Depolarization
Voltage Gated Na channels open –> +feedback loop
Repolarization
Voltage Gated K+ channels Open –> -Feedback loop –> return to resting AP
Hyperpolarization
More Negative than resting membrane potential
Absolute refractory period
Incapable of producing another AP
Relative Refractory period
can produce another AP but requires a stronger stimulus
Cable Properties
Ability of a neuron to transmit a charge through the cytoplasm
Unmyelinated neuron
depolarizes adjacent membrane propagating the AP. SLOW CONDUCTION RATE
Myelinated neuron
prevents movement of Na and K through the membrane. Nodes of Ranvier contain VG Na and K channels FAST CONDUCTION
G0 Phase
Normal cellular function, resting cell
G1 Phase
Period between M phase and start of DNA Synthesis, Increased protein synthesis
S Phase
DND replication occurs
G2 Phase
Rapid cellular growth
Prophase
DNA replicates, condensed to chromosomes Nuclear membrane disapears, spindle fibres form at opposite ends
Metaphase
Chromosome pairs line up at midline of cell and attach to miotic spindle
Anaphase
sister chromatids separate, move to opposite poles, 92 nchromosomes in the cell
Telophase
New nuclear membrane formed around each group of 46 chromosomes
Cytokines
Cytoplasm separates into equal parts, 2 daughter cells form