MODULE 1: The Cell
THE CELL
1. Identify and briefly describe the basic organization of the cell
1.1. Its structural components
1.1.1. Major parts of the cell
a. Nucleus
b. Cytoplasm
1.1.2. Cytoplasm
1.1.2.1. Cytosol – fluid
1.1.2.2. Formed Elements
a. Organelles
− Metabolically active, perform essential & specific functions
− bounded by membranes composed of lipid & protein
− capable of regeneration
− 3 are viewed under LM: mitochondria, ergastoplasm, golgi complex
− IMPTCE:
▪ Enhance efficiency of chemical reactions
▪ Control of cell metabolism
b. Inclusion
− Metabolically inert
− Dispensable, temporary constituents of cells
c. Cytoplasm
− Fibrillar elements
2. Nucleus
- largest organelle, repository of DNA, archive of cell
- FXN:
a. Constructive cell metabolism
b. Cell reproduction & genetic transmission
2.1. Parts of the nucleus
2.1.1. Nuclear Envelope
2.1.2. Nucleolus
- consist mainly of ribonucleoprotein
- disappears during cell division
- reappears during reconstruction
- Nucleolus-Associated Chromatin - intensely stained that surrounds the rim of the nucleolus
- the network:
1. Nucleolonema / Pars Granulosa
- ribonucleoprotein particles in a matrix of fine filaments
- anastomosing dense strands
- site of ribonucleoprotein particle accumulation
2. Fibrillar Centers
- fibrillar texture
- less dense rounded areas found at 2 or more sites in the nucleolus
- contain Nucleolar-Organizer Regions
*possess the nucleolar genes
*site of transcription of rRNA
3. Dense Fibrillar Component / Pars Fibrosa
- rim of electron-dense filaments that immediately surrounds fibrillar centers
- site of processing RNA precursor & RNA protein assembly
-types:
1. Pyknotic - dark chromatin (basophilic)
2. Vesicular - pale
2.1.3. Chromatin
2.1.4. Identify the terms to describe the chromatin pattern and staining
Types:
a. heterochromatin
- stainable, electron-dense portion of the interphase chromosomes
- coiled, condensed, clumped, granular
- inactive portions that are being transcribed
- unexpressed genes
- in special preparations, appear as a beaded strand of regularly spaced discoid subunits
nucleosomes - the core is an octomer of 2 molecules each of histones: H4, 3, 2A, 2B
H1 is associated with the connecting segments of DNA.
b. euchromatin
- non-stainable, unidentifiable on LM
- dispersed portion
- uncoiled, loosely packed, conjectural
- active genes involved in protein synthesis
, 2.2. Identify the sex chromatin and its significance
2.3. Identify and describe the different types of chromosomes based on the location of the centromere
2.3.1. Metacentric
2.3.2. Submetacentric
2.3.3. Acrocyanotic
2.3.4. Telocentric
2.4. Identify the chemical compositions and their biochemical roles
3. Identify and differentiate the macromolecules of the cell
3.1. Its monomeric units or building blocks
3.2. Its linkages or bonds
4. Identify and describe the different organelles
Light microscope Electron microscope Biochemical role
Nucleus
a. nuclear envelope - thin dark line surrounding the - double layered membrane - organization of chromatin
nucleus with perinuclear space - controls the movement of
- fenestrated by nuclear macromolecules between nucleoplasm
pores & cytoplasm
Chromatin - dark irregular masses in the - made up of
a. Heterochromatin nucleoplasm filaments/strands of DNA
- stainable, electron-dense portion of the - (+) Feulgen rxn, deeply
interphase chromosomes stained with acidic dyes
- coiled, condensed, clumped, granular since basophilic
- inactive portions that are being transcribed
- unexpressed genes
- in special preparations, appear as a beaded
strand of regularly spaced discoid subunits
nucleosomes - the core is an octomer
of 2 molecules each of histones: H4, 3, 2A, 2B
H1 is associated with the connecting
segments of DNA.
b. Euchromatin
- non-stainable, unidentifiable on LM - unidentiful environment
- dispersed? - non-stainable
- uncoiled, loosely packed, conjectural
- active genes involved in protein synthesis
Nucleolus - rounded refractile body usually - tightly coiled filaments of
located eccentrically in the RNA / has a 3D network of
nucleus anastomosing dense strands
Cell membrane (plasmalemma) - not visible - thin dense line, 8.5 – 10nm - permit diffusion of ions & gases in
- phospholipid bilayer thick around periphery (d/t solution into & out of cell
- permeable to H2O, O2, N & small, uncharged heavy metal deposits) - device for cell attachments &
polar molecules - Cresyl violet - basophilic communication
- glycocalyx stained by Alcian-Blue and - trilaminar
Ruthenium Red
Endoplasmic Reticulum
- visible using lipophilic, non ionic, fluorescent
dyes
a. Rough ER - Cresyl violet – dark staining - branching and - protein synthesis
irregular basophilic masses anastomosing tubules with - cisternae – broad flat saccules from
dark, staining palade expanded tubules
granules / ribosomes
- steroid secreting endocrine glands
b. Smooth ER - can’t be seen - similar to R ER w/o - liver: synthesis of fatty acids & other
ribosomes lipids (VLDL); detoxification and
metabolism of lipid soluble drugs
- skeletal & cardiac muscle:
sequestration of Ca ions for muscle
contraction; sarcoplasmic reticulum
Ribosomes - amino acid assembly
- RNA + 20+ proteins
- mRNA
- polyribosome / polysome – 10+ clusters linked to
mRNA
Golgi Complex - silver stain / osmium acid – - flattened membranous - further processing, concentration and
blackened area near nucleus sacs stacked close packaging in secretory granules
THE CELL
1. Identify and briefly describe the basic organization of the cell
1.1. Its structural components
1.1.1. Major parts of the cell
a. Nucleus
b. Cytoplasm
1.1.2. Cytoplasm
1.1.2.1. Cytosol – fluid
1.1.2.2. Formed Elements
a. Organelles
− Metabolically active, perform essential & specific functions
− bounded by membranes composed of lipid & protein
− capable of regeneration
− 3 are viewed under LM: mitochondria, ergastoplasm, golgi complex
− IMPTCE:
▪ Enhance efficiency of chemical reactions
▪ Control of cell metabolism
b. Inclusion
− Metabolically inert
− Dispensable, temporary constituents of cells
c. Cytoplasm
− Fibrillar elements
2. Nucleus
- largest organelle, repository of DNA, archive of cell
- FXN:
a. Constructive cell metabolism
b. Cell reproduction & genetic transmission
2.1. Parts of the nucleus
2.1.1. Nuclear Envelope
2.1.2. Nucleolus
- consist mainly of ribonucleoprotein
- disappears during cell division
- reappears during reconstruction
- Nucleolus-Associated Chromatin - intensely stained that surrounds the rim of the nucleolus
- the network:
1. Nucleolonema / Pars Granulosa
- ribonucleoprotein particles in a matrix of fine filaments
- anastomosing dense strands
- site of ribonucleoprotein particle accumulation
2. Fibrillar Centers
- fibrillar texture
- less dense rounded areas found at 2 or more sites in the nucleolus
- contain Nucleolar-Organizer Regions
*possess the nucleolar genes
*site of transcription of rRNA
3. Dense Fibrillar Component / Pars Fibrosa
- rim of electron-dense filaments that immediately surrounds fibrillar centers
- site of processing RNA precursor & RNA protein assembly
-types:
1. Pyknotic - dark chromatin (basophilic)
2. Vesicular - pale
2.1.3. Chromatin
2.1.4. Identify the terms to describe the chromatin pattern and staining
Types:
a. heterochromatin
- stainable, electron-dense portion of the interphase chromosomes
- coiled, condensed, clumped, granular
- inactive portions that are being transcribed
- unexpressed genes
- in special preparations, appear as a beaded strand of regularly spaced discoid subunits
nucleosomes - the core is an octomer of 2 molecules each of histones: H4, 3, 2A, 2B
H1 is associated with the connecting segments of DNA.
b. euchromatin
- non-stainable, unidentifiable on LM
- dispersed portion
- uncoiled, loosely packed, conjectural
- active genes involved in protein synthesis
, 2.2. Identify the sex chromatin and its significance
2.3. Identify and describe the different types of chromosomes based on the location of the centromere
2.3.1. Metacentric
2.3.2. Submetacentric
2.3.3. Acrocyanotic
2.3.4. Telocentric
2.4. Identify the chemical compositions and their biochemical roles
3. Identify and differentiate the macromolecules of the cell
3.1. Its monomeric units or building blocks
3.2. Its linkages or bonds
4. Identify and describe the different organelles
Light microscope Electron microscope Biochemical role
Nucleus
a. nuclear envelope - thin dark line surrounding the - double layered membrane - organization of chromatin
nucleus with perinuclear space - controls the movement of
- fenestrated by nuclear macromolecules between nucleoplasm
pores & cytoplasm
Chromatin - dark irregular masses in the - made up of
a. Heterochromatin nucleoplasm filaments/strands of DNA
- stainable, electron-dense portion of the - (+) Feulgen rxn, deeply
interphase chromosomes stained with acidic dyes
- coiled, condensed, clumped, granular since basophilic
- inactive portions that are being transcribed
- unexpressed genes
- in special preparations, appear as a beaded
strand of regularly spaced discoid subunits
nucleosomes - the core is an octomer
of 2 molecules each of histones: H4, 3, 2A, 2B
H1 is associated with the connecting
segments of DNA.
b. Euchromatin
- non-stainable, unidentifiable on LM - unidentiful environment
- dispersed? - non-stainable
- uncoiled, loosely packed, conjectural
- active genes involved in protein synthesis
Nucleolus - rounded refractile body usually - tightly coiled filaments of
located eccentrically in the RNA / has a 3D network of
nucleus anastomosing dense strands
Cell membrane (plasmalemma) - not visible - thin dense line, 8.5 – 10nm - permit diffusion of ions & gases in
- phospholipid bilayer thick around periphery (d/t solution into & out of cell
- permeable to H2O, O2, N & small, uncharged heavy metal deposits) - device for cell attachments &
polar molecules - Cresyl violet - basophilic communication
- glycocalyx stained by Alcian-Blue and - trilaminar
Ruthenium Red
Endoplasmic Reticulum
- visible using lipophilic, non ionic, fluorescent
dyes
a. Rough ER - Cresyl violet – dark staining - branching and - protein synthesis
irregular basophilic masses anastomosing tubules with - cisternae – broad flat saccules from
dark, staining palade expanded tubules
granules / ribosomes
- steroid secreting endocrine glands
b. Smooth ER - can’t be seen - similar to R ER w/o - liver: synthesis of fatty acids & other
ribosomes lipids (VLDL); detoxification and
metabolism of lipid soluble drugs
- skeletal & cardiac muscle:
sequestration of Ca ions for muscle
contraction; sarcoplasmic reticulum
Ribosomes - amino acid assembly
- RNA + 20+ proteins
- mRNA
- polyribosome / polysome – 10+ clusters linked to
mRNA
Golgi Complex - silver stain / osmium acid – - flattened membranous - further processing, concentration and
blackened area near nucleus sacs stacked close packaging in secretory granules
