Cells: Basic Units of Life
Eukaryotic Cell
In this lesson
In your book
1.
Eukaryotic cells and compartmentalisation
Pag. 5
2.
Cell Structure Overview
Pag. 14-20
3.
Differences between animal and plant cells
Pag. 5-6
Prof. Vincenzi Chiara
CAMBRIDGE BIOLOGY
2
Vocabulary - 1
English
Italian
Nucleus
Nucleo
Nucleolus
Nucleolo
Chromatin
Cromatina
Chromosomes
Cromosomi
Nuclear envelope
Membrana nucleare
Nuclear pores
Pori nucleari
Endoplasmic reticulum rough / smooth
Reticolo endoplasmatico ruvido / liscio
Golgi apparatus (body)
Apparato di Golgi
Prof. Vincenzi Chiara
CAMBRIDGE BIOLOGY
3
Eukaryotic cells and compartmentalisation
• Eukaryotic cells contain
organelles (such as nucleus).
• An organelle is a intracellular,
membrane-bound structure
that performs a specific
functions for the cell.
o Eukaryotic cells can carry out
more functions than prokaryotic
cells.
o Eukaryotic cells can have greater
cell specificity than prokaryotic
cells.
Prof. Vincenzi Chiara
CAMBRIDGE BIOLOGY
4
Cell Specialization
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Warm Up!
Video: The Cell is Like a City
Worksheet – Cell City
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6
Cell Structures Overview
Organelle
Organelle
Nucleus
Vesicles and vacuoles
Nucleolus
Centrioles
Endoplasmic reticulum (ER):
smooth & rough
Other cellular structures:
Golgi body
Plasma membrane
Ribosomes
Cell wall
Mitochondria
Cytoplasm
Cloroplasts
Cytoskeleton
Lysosomes
Cilia
Peroxisomes
Flagella
Prof. Vincenzi Chiara
CAMBRIDGE BIOLOGY
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Cells gotta work to live!
• What jobs do cells have to do?
• make proteins
• proteins control every
cell function
• make energy
• for daily life
• for growth
• make more cells
• growth
• repair
• renewal
Prof. Vincenzi Chiara
CAMBRIDGE BIOLOGY
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Cell structure
1 – Building Proteins
Prof. Vincenzi Chiara
CAMBRIDGE BIOLOGY
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The Nucleus - 1
Structure
o Surrounded by a double membrane
(nuclear envelope).
o The outer membrane is continuous with
the endoplasmic reticulum.
o The nuclear envelope contains “holes”
called nuclear pores.
o They allow movement of materials
between nucleus and cytoplasm.
Function
o Contains the hereditary material
(deoxyribonucleic acid – DNA), coding for
the synthesis of proteins in the
cytoplasm.
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CAMBRIDGE BIOLOGY
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The Nucleus - 2
Inside of the nucleus:
o The DNA can be organized in
two ways:
o Between cell divisions: a mass of
DNA not condensed (chromatin).
o During cell division: DNA
condensed in structures called
chromosomes (visible).
o Nucleolus: a dense DNA region
of the nucleus where the rRNA
(ribosomal rna) and ribosomes
are made.
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Chromatin
During cell division:
Chromosomes
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The Endoplasmic Reticulum - 1
Structure
o System of membranes running
through the cytoplasm like a
network.
o Membranes are organized in flattened,
enclose compartments or tube-like
structures known as sacs.
o The membranes of the ER are
continuous with the outer nuclear
membrane.
Function
o It acts as an intracellular highway that
transports molecules from one part
of the cell to another.
Prof. Vincenzi Chiara
CAMBRIDGE BIOLOGY
Micrograph of rough endoplasmic reticulum network around the
nucleus (shown in lower right-hand side of the picture). Dark small
circles in the network are mitochondria.
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The Endoplasmic Reticulum - 2
There are two types, Smooth ER and
Rough ER.
Rough ER:
o“rough” because covered with many
ribosomes (visible as black dots).
oFunctions: transporting proteins
synthesized on the ribosomes in small
sacs (vescicles) to Golgi apparatus.
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CAMBRIDGE BIOLOGY
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The Endoplasmic Reticulum - 3
Smooth ER:
oFew or no ribosomes.
oInterconnetted with the
rough ER.
oFunctions:
Rough RE
o synthesis of carbohydrates,
lipids and steroids (such as
phospholipids, cholesterol
and reproductive
hormones);
o detoxification of
medications and poisons;
o alcohol metabolism;
o storage of calcium ions.
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Smooth RE
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Ribosomes
• Small spherical
organelles that are
responsible for
building protein
molecules.
• The do not have a
membrane!
• Some ribosomes are
free in the cytosol
others are attached to
the ROUGH ER.
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CAMBRIDGE BIOLOGY
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The Golgi Apparatus
Structure
o A system of FLATTENED,
membranous sacs that extend
from the endoplasmic
reticulum.
o It receives and releases
vesicles from the ER to other
parts of the cell.
Function
o It collects, modifies and moves
molecules from
the endoplasmic reticulum to
their destination (inside or
outside the cell).
Video: The Golgi Apparatus
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vesicle
vesicle
protein
p oein
rt
1) Nucleolus makes ribosomes
2) Ribosome travels through rough ER making proteins
3) Golgi Body sorts & packages the protein
4) Vesicle releases the protein from the cell
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CAMBRIDGE BIOLOGY
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1 Minute Activity
Ribosome
1. Which organelle builds proteins? ____________
Nucleus
2. Stores DNA? ____________
Nucleolus
3. Produces ribosomes? ___________
Smooth ER
4. Creates fats and breaks down toxins? ___________
Golgi apparatus
5. Packages and releases proteins from a cell? __________
Cell membrane
6. Allows material to enter/exit a cell? ______________
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1 Minute Activity
Place the following steps of protein creation in order from start to finish…
A. Golgi body packages and exports the finished proteins in a vesicle
B. Ribosomes travel along the rough ER and create proteins
C. Nucleolus makes ribosomes
4.
3.
1.
D. Ribosomes exit the nucleus
2.
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