Notes on Cell Components
Rahul's Noteblog Notes on Anatomy Notes on Cell Components
Types of chromatin:
• Heterochromatin: condensed, inactive.
• Euchromatin: extended, active.
RER Functions:
• Synthesize proteins destined for Golgi apparatus.
SER Functions:
• Steroid synthesis, hydroxylation, conjugation (transfer of polar groups from active carrier UDP-glucuronic acid to toxic water-insoluble molecules).
• Removal of phosphate group from G6P; controls glucose levels; gluconeogenesis.
• Lipolysis and sequestration and release of Ca ions.
Golgi apparatus functions:
• Post-translational modifications and sorting of new proteins.
• Further modifications of glycoproteins.
Golgi apparatus dysfunction:
Hyperproinsulinemia:
• A peptidase cannot cleave proinsulin to insulin and C-peptide; insulin deficiency.
I-Cell disease:
• Deficiency of N-acetylglucosamine-phosphotransferase causes absence of mannose-6-phophate on hydrolases results in their secretion rather than their incorporation into lysosomes.
Lysosomes:
• Low pH.
• Primary: empty.
• Secondary: formed by fusion of primary lysosomes with substrates to be degraded.
Peroxisomes:
• Synthesis/degradation of H2O2.
• Beta-oxidation of very long chain fatty acids.
• Phospholipid exchange.
• Bile acid synthesis.
Mitochondria:
• Synthesize ATP; contain their own circular dsDNA, and create some of their own proteins.
• Outer membrane: abundant in porins.
• Inner membrane contains enzymes for ETC and oxidative phosphorylation.
• Matrix generates NADH and FADH2 for use in ETC.
Microtubules:
• Structural support, axonal transport.
• Make cilia.
Tubulin:
• Microtubule synthesis and assembly; kinesin and dynein-related transport, ciliary and flagellar movement.
• Tubulin gives rise to microtubules, which give rise to cilia.
Intermediate filaments:
• Structural roles.
Microfilaments:
• Movements.
• Composed of actin and myosin.
• Inhibited by actin-binding drugs.
• Make microvilli.
Cilia:
• 2+9 structure.
• Propulsion of particles in one direction.
Additional Notes:
• Bright red blood: cyanide poisoning.
• Anaerobic metabolism: cytoplasm.
• Oncocytes: large # of mitochondria.
• Nuclear membrane is formed from RER after cell-division.
• ETC enzymes: mitochondrial cristae.
• Microfilaments: actin + myosin.
• Tyrosine kinases: involved in DNA synthesis.
• Bcl-2: found in mitochondria.
• Phosphorylation of serine residues on cyclines: tumor cells.
Additional Reading:
Histology and Cytology
1. Cell Components
2. Nervous Tissue
3. Muscle Tissue
4. Lymphoid Tissue
5. Integument
6. Respiratory System
7. Gastrointestinal System
8. Renal/Urinary System
9. Male Reproductive System
10. Female Reproductive System
Gross Anatomy
1. Back and Nervous System
2. Thorax
3. Abdomen, Pelvis, and Perineum
4. Upper Limb
5. Lower Limb
6. Head and Neck
7. Chest Wall
8. Shoulder
Anatomy Videos
1. Video of Musculoskeletal Examination in a Clinical Setting
1. Video of HEENT Examination in a Clinical Setting
Related Topics
1. Jugular Venous Distention Workup
Medical Images
Useful Medical Images & Diagrams (link opens in a new window)
Random Pages:
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