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HUMAN ANATOMY AND PHYSIOLOGY I
Lecture: M 6-9:30 Randall Visitor Center
Lab: W 6-9:30 Swatek Anatomy Center, Centennial Complex
Required Text: Marieb 9th edition
Dr. Trevor Lohman DPT
(949) 246-5357
THE CELL
CH. 3: THE FUNCTIONAL UNIT OF LIFE
THE CELLULAR BASIS OF LIFE The Smallest Living Unit
Cell Theory:
Generalized or Composite Cell
• Plasma Membrane
• Cytoplasm
• Nucleus
Fig 3.2
THE PLASMA MEMBRANE: STRUCTURE
The Fluid Mosaic Model
Membrane Lipids
• Phospholipids
• Glycolipids
• Cholesterol
• Lipid Rafts
• Fig 3.3
PLASMA MEMBRANE: STRUCTURE
Membrane Proteins:
• Integral Proteins
• Peripheral Proteins
• The Glycocalyx
• Fig 3.3-3.4
CELL JUNCTIONS
Tight Junctions:
Desmosomes:
Gap Junctions:
THE PLASMA MEMBRANE: MEMBRANE TRANSPORTPassive Processes
• Osmosis
• Aquaporins• Osmolarity• Hydrostatic vs. osmotic pressure• Tonicity (Iso, Hyper, Hypo)• Fig 3.9
• Diffusion
• Simple diffusion• Facilitated diffusion• Carrier-Mediated facilitated diffusion• Channel-Mediated facilitated diffusion• Fig 3.6, 3.7, 3.8
THE PLASMA MEMBRANE: MEMBRANE TRANSPORT
Active Transport
• Primary Active Transport (3.10)
• Sodium-potassium pump• Secondary Active Transport (3.11)
• Symport system vs. antiport system• Vesicular Transport (3.12- 3.13)
• Endocytosis, Transcytosis, Vesicular Trafficking Fig 3.12• Phagocytosis• Pinocytosis• Receptor Mediated endocytosis• Exocytosis
THE PLASMA MEMBRANE: GENERATION OF A RESTING MEMBRANE POTENTIAL
Membrane Potential and Resting Membrane Potential
Selective Diffusion Establishes Membrane Potential
• Fig 3.15
• Step 1• Step 2• Step 3
Active Transport Maintains Electrochemical Gradients
THE PLASMA MEMBRANE: CELL-ENVIRONMENT INTERACTIONS
Roles of Cell Adhesion Molecules
• Molecular Velcro
• The “arms”
• Send SOS signals
• The Mechanical Sensors
• The Transmitters of intracellular signals
THE PLASMA MEMBRANE: CELL-ENVIRONMENT INTERACTIONS
Roles of Plasma Membrane Receptors
• Contact Signaling
• Chemical Signaling
• Ligands• Catalytic receptor proteins• Chemically gated channel-link
receptors• G-linked receptors
• Second messengers• Cyclic AMP• Ionic calcium• Fig 3.16
THE CYTOPLASM
The Cytosol
Organelles
Inclusions
CYTOPLASMIC ORGANELLES
Mitochondria
Ribosomes
CYTOPLASMIC ORGANELLES
Endoplasmic Reticulum
• Smooth endoplasmic reticulum
• Rough Endoplasmic reticulum
CYTOPLASMIC ORGANELLES
Golgi Apparatus
• Trans face
• Cis face
CYTOPLASMIC ORGANELLES
Peroxisomes
• Neutralize free radicals
Lysosomes
CYTOPLASMIC ORGANELLES
Cytoskeleton
• Microfilaments
• Intermediate filaments
• Microtubules
CYTOPLASMIC ORGANELLES
• Centrosome
• Centrioles
• Fig 3.25
THE NUCLEUSThe Nucleus
• Multinucleate
• Anucleate
3 distinguishable regions
• The Nuclear Envelope
• Nuclear Pores• Nucleoli
• Chromatin
• 30% DNA• 60% globular histone proteins• 10% RNA chains• Nucleosomes• Chromosomes
CELL CYCLE: INTERPHASE/M-PHASEInterphase (Metabolic/Growth Phase)
• Subphases
• G1 (gap 1 subphase)/(G0 phase)
• S Phase• G2 (gap 2 subphase)
• DNA Replication
• Enzymatic Unwinding• Replication bubble
forms
• RNA Primer Formation• DNA Polymerase
CELL DIVISION
Cell Division
• M (mitotic) phase
• Mitosis• Prophase• Metaphase• Anaphase• Telophase
• Cytokinesis
MITOSISProphase
• Early Prophase
• Chromatin condenses, forms chromosomes
• Centrosome separation, Mitotic spindle forms
• Late Prophase
• Nuclear envelope dissolves• Spindle microtubules attach to
kinetochores at each centromere• Polar microtubules slide past
each other forcing the poles apart
Fig 3.33
MITOSIS
Metaphase
• Centromeres are at opposite poles of the cell
• Chromosomes align along the equator of the spindle or metaphase plate
• Enzymatic separation of chromatids begins
ANAPHASE• Shortest Mitotic Phase
• Begins with simultaneous chromatid separation
• Motor proteins within the kinetochores pull chromosomes toward the poles
• Polar microtubules continue to expand, pushing the poles further apart
TELOPHASE• Begins when
chromosomal movement stops
• Resembles prophase in reverse
• Chromosomes unravel and revert to chromatin
• New nuclear envelopes form and nucleoli reform
• Mitotic spindle disappears
• Mitosis ends, and cell is now binucleate
CYTOKINESIS• Actin ring forms and
constricts until cell is pinched in two
• Begins during late Anaphase
• Continues beyond Telophase
PROTEIN SYNTHESIS
Deoxyribose Nucleic Acid
• DNA is the master blueprint
• Composed of 4 nucleotide bases A, T, C, G
• Triplets code for individual amino acids
• Exons and introns
• DNA is useless without RNA
PROTEIN SYNTHESIS
RNA
• Messenger RNA (mRNA)
• The “transcript” from which protein synthesis is performed
• Ribosomal RNA (rRNA)
• Building block of ribosomes
• Transfer RNA (tRNA)
• Transport cytoplasmic amino acids to ribosomes
PROTEIN SYNTHESIS
Transcription
• Initiation
• RNA Polymerase• Promoter• Helix pulled apart
• Elongation
• Helix unwound and rewound and as mRNA formed
• Termination
• Termination signal• mRNA separation
PROTEIN SYNTHESISTranslation
• Nucleic acid language translated to amino acid language
• Codons (64 possible)
Translation Events
• Initiation
• Ribosomal subunit binds to initiating tRNA which scans for start codon
• Elongation
• Codon recognition• Peptide bond formation• Translocation
• Termination
• Stop codon reached• Polypeptide chain released
PROTEIN SYNTHESIS
Fig 3.4
Fig 3.39
CH 3: THE CELL
Study Guide