1.2 Eukaryotic Cells
IB HL Biology
Essential Idea
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Eukaryotes have much more complex cell
structures than prokaryotes
Eukaryotic Cells
Algae
Fungi
Plants
Animals
Eukaryotic Properties
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More complicated than prokaryotic
Nucleus with a nuclear membrane
Many membrane-bound organelles with
distinct functions
10-100 m
Eukaryotic Cell Structure
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Nucleus – double
membrane control
centre
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Store DNA
chromosomes in form
of chromatin
DNA replication and
transcription
Nucleolus – in the
nucleus
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Made of RNA
Makes ribosomes
Eukaryotic Cell Structure
Ribosomes
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Ribosomes – link amino
acids into proteins like
enzymes
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Made in the nucleolus
Made of RNA and protein
~ 20nm
Size = 80s
Eukaryotic Cell Structure
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Endoplasmic ReticulumFolded membrane that
carries materials through
cytoplasm
Make proteins for secretion
to outside the cell
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Rough ER (rER)
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Covered in ribosomes
Makes proteins
Smooth ER (sER)
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No ribosomes
Synthesize fats and lipids
Eukaryotic Cell Structure
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Golgi apparatus – folded
membrane for storing,
processing and packaging
proteins from rER
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Mitochondria – double
membrane with enzymes
on cristae (folds)
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What kind of cell would have
lots of mitochondria? Why?
Create vesicles (small sac)
Exocytosis - sac fuses with
cell membrane and empties
contents outside of cell
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Inside called matrix
Produce large amount of ATP
for cell by cell respiration
Power plant of cell
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Lysosome
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Created by Golgi
Apparatus
Vesicle filled with
hydrolytic enzymes
Breakdown and
recycle cell parts
and biomolecules
Eukaryotic
Cell
Micrographs
Mitochondrion
Golgi apparatus
Nucleus
Lysosome
Liver Cell Micrographs
Rough ER
Mitochondrion
Free ribosome
Liver Cell Micrographs
Mitochondrion
Rough ER
Cell membrane
Nucleus
2.3.1 Draw and label a diagram of the ultra
structure of the liver as an example of an animal
cell
Differences between
Prokaryotic and Eukaryotic Cells
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Prokaryotes
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Smaller
Single, circular DNA
DNA in cytoplasm (no
nucleus)
Small ribosomes (70S)
Usually no extra
membranes: no
mitochondria, ER, golgi,
chloroplasts, vacuole, etc.
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Eukaryotes
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Larger, containing multiple
mitochondria
Multiple strings of DNA
organized by proteins
DNA in nuclear membrane
Large ribosomes (80S)
Many extra membranes
forming compartments for
special jobs for many
organelles
Plant & Animal Cells
Animal Cell
Plant and animal cell differences
Plant
Animal
Cell wall (cellulose)
For structure, support
and regular shape.
No cell wall
Large central vacuole
May have small
temporary vacuoles
Autotrophs
Heterotrophs
Chloroplast photosynthesis
No chloroplast
Carbs stored as starch
Carbs stored as
glycogen (some fat)
Centrioles (mitosis)
No centrioles
Structures outside the cell:
Cell wall of plants
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Primary cell wall
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Non-living
Cell wall is made of cellulose
(carbohydrate)
Cellulose makes microfibril
bundles with other molecules
Supports
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Cell shape
Overall plant shape (opposes
gravity)
Storage of carbohydrates
Prevents the cell from
absorbing too much water and
bursting (lysis)
Structures outside the cell:
Animal Extracellular Matrix
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Glycoproteins
 proteoglycan
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Plays a role in
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Support
Adhesion
Movement
Helps in
embryonic
development
IB Objectives
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Eukaryotes have a compartmentalized cell
structure.
Skill: Drawing of the ultrastructure of
eukaryotic cells based on electron
micrographs
Skill: Interpretation of electron micrographs to
identify organelles and deduce the function of
specialized cells.
Task:
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Venn Diagram of prokaryotic and eukaryotic
cells