University of Santo Tomas
Faculty of Pharmacy, BS Pharmacy Batch 2027
PHA611: Pharmaceutical Botany with Taxonomy (Laboratory)
Exercise 3: Plant Cytology
Cytology: study of structure, function, and behavior of cells
PLANT CELL ORGANELLES
Cell wall
• Provides support
• Distinguishing feature in terms of chemical component
(cellulose)
• Limits the size of the cell
• Protects cellular components
Microfilament
• May also contain lignin for rigidity, cutin and suberin
• Globular protein (actin, myosin) for support
(found on tree bark; makes tree unpalatable) for anti-
water loss
Intermediate filament
Plasmodesmata • Fibrous protein for support
• Fine holes in the primary cell wall
• Interconnects plant cells Microtubules
• Transfers nutrients from cell to cell • Globular protein (tubulin) for support and cell motility
• Most abundant
Cell membrane (plasma membrane)
• Assemble into antenna-like arrays to guide vesicles
• Regulates the passage of molecules (primarily water) in
and out of the cell
• Divides the cell into compartments
• Holds enzymes
• Selectively permeable (hydrophobic, lipid soluble
compounds may enter)
Cytoplasm
• Fluid portion containing all organelles
• Composed mainly of water
Cytoskeleton
• Network of fibers throughout the cytoplasm
• Aids in cellular support and movement
• Protein synthesis site for free ribosomes Protein synthesis site
• RNA: ribonucleic acid
o mRNA: messenger RNA
▪ ribbon-like molecule
▪ translation of proteins in DNA
▪ synthesized from DNA via transcription
1|P a g e
LIANRPh
, University of Santo Tomas
Faculty of Pharmacy, BS Pharmacy Batch 2027
PHA611: Pharmaceutical Botany with Taxonomy (Laboratory)
different codons temporarily join to tRNA
▪ • Without histone, DNA chromosome would be
anticodon prokaryotic
o tRNA: transfer RNA • DNA + histone = chromatins
▪ four leaf clover shape • Condensed chromatin = chromatids
▪ carries an amino acid (anticodon) added to an • 2 chromatids = chromosome
end of a growing protein chain • Rapidly dividing cells = more DNA
o rRNA: ribosomal RNA
▪ non-coding RNA
▪ major constituent of ribosomes
Endoplasmic reticulum (ER)
• Cannot be seen in light microscope
• Attached to nucleus
• Carries large molecules (e.g. protein) that cannot be
transported via diffusion
• System/network of narrow tubes and sheets of
Nucleus membrane throughout the cytoplasm
• control center of the cell o Cisternae: folds in ER fused together; attached to
dictyosome
• contains cell’s DNA
▪ Cisternal space: space in between cisternae
• surrounded by 2 enveloping membranes
o main membrane (double membrane): nuclear
Smooth ER (SER)
membrane/envelope
• Lipid synthesis
▪ nuclear pores: synthesized RNA exit to
• Lipids produced aid in phospholipid bilayer formation
protoplasm
• Membrane assembly
o nucleoplasm/karyoplasm/karyolymph (liquid
• Plants that secrete oil (e.g. scented flowers) and
portion)
epidermal cells have abundant SER
▪ contains DNA, enzymes, histone protein, RNA,
water
Rough ER (RER)
• nucleus and nucleoplasm are different in different ages
• Protein synthesis
of the cell
• Storage products (e.g. legumes) remain in ER
• young cell: small with large nucleus
• Other proteins (e.g. mucilage, nectar) exit to plasma
• mature cell: large with small nucleus
membrane via exocytosis
Nucleolus
Ribosomes
• RNA synthesis
• Macromolecular machines for mRNA translation
• Site of ribosomes production and assembly
• Ribosome + mRNA = polysome
Histone • Attached to RER
2|P a g e
LIANRPh
Faculty of Pharmacy, BS Pharmacy Batch 2027
PHA611: Pharmaceutical Botany with Taxonomy (Laboratory)
Exercise 3: Plant Cytology
Cytology: study of structure, function, and behavior of cells
PLANT CELL ORGANELLES
Cell wall
• Provides support
• Distinguishing feature in terms of chemical component
(cellulose)
• Limits the size of the cell
• Protects cellular components
Microfilament
• May also contain lignin for rigidity, cutin and suberin
• Globular protein (actin, myosin) for support
(found on tree bark; makes tree unpalatable) for anti-
water loss
Intermediate filament
Plasmodesmata • Fibrous protein for support
• Fine holes in the primary cell wall
• Interconnects plant cells Microtubules
• Transfers nutrients from cell to cell • Globular protein (tubulin) for support and cell motility
• Most abundant
Cell membrane (plasma membrane)
• Assemble into antenna-like arrays to guide vesicles
• Regulates the passage of molecules (primarily water) in
and out of the cell
• Divides the cell into compartments
• Holds enzymes
• Selectively permeable (hydrophobic, lipid soluble
compounds may enter)
Cytoplasm
• Fluid portion containing all organelles
• Composed mainly of water
Cytoskeleton
• Network of fibers throughout the cytoplasm
• Aids in cellular support and movement
• Protein synthesis site for free ribosomes Protein synthesis site
• RNA: ribonucleic acid
o mRNA: messenger RNA
▪ ribbon-like molecule
▪ translation of proteins in DNA
▪ synthesized from DNA via transcription
1|P a g e
LIANRPh
, University of Santo Tomas
Faculty of Pharmacy, BS Pharmacy Batch 2027
PHA611: Pharmaceutical Botany with Taxonomy (Laboratory)
different codons temporarily join to tRNA
▪ • Without histone, DNA chromosome would be
anticodon prokaryotic
o tRNA: transfer RNA • DNA + histone = chromatins
▪ four leaf clover shape • Condensed chromatin = chromatids
▪ carries an amino acid (anticodon) added to an • 2 chromatids = chromosome
end of a growing protein chain • Rapidly dividing cells = more DNA
o rRNA: ribosomal RNA
▪ non-coding RNA
▪ major constituent of ribosomes
Endoplasmic reticulum (ER)
• Cannot be seen in light microscope
• Attached to nucleus
• Carries large molecules (e.g. protein) that cannot be
transported via diffusion
• System/network of narrow tubes and sheets of
Nucleus membrane throughout the cytoplasm
• control center of the cell o Cisternae: folds in ER fused together; attached to
dictyosome
• contains cell’s DNA
▪ Cisternal space: space in between cisternae
• surrounded by 2 enveloping membranes
o main membrane (double membrane): nuclear
Smooth ER (SER)
membrane/envelope
• Lipid synthesis
▪ nuclear pores: synthesized RNA exit to
• Lipids produced aid in phospholipid bilayer formation
protoplasm
• Membrane assembly
o nucleoplasm/karyoplasm/karyolymph (liquid
• Plants that secrete oil (e.g. scented flowers) and
portion)
epidermal cells have abundant SER
▪ contains DNA, enzymes, histone protein, RNA,
water
Rough ER (RER)
• nucleus and nucleoplasm are different in different ages
• Protein synthesis
of the cell
• Storage products (e.g. legumes) remain in ER
• young cell: small with large nucleus
• Other proteins (e.g. mucilage, nectar) exit to plasma
• mature cell: large with small nucleus
membrane via exocytosis
Nucleolus
Ribosomes
• RNA synthesis
• Macromolecular machines for mRNA translation
• Site of ribosomes production and assembly
• Ribosome + mRNA = polysome
Histone • Attached to RER
2|P a g e
LIANRPh
