Malaysia Chinese Independent School Senior 1 Biology (English)

1. 2.2.3 Cytoplasm

2. Cytoplasm 细胞质
• Material within the plasma membrane of a
living cell, excluding the cell nucleus.
• Free-flowing within living cells.
• Some organisms may have obvious cyclosis
细胞质流 - directed flow of cytosol and
organelles within the cell without disruption
of the cell membrane.
• Consists of cytosol 细胞质基质 and the
organelles 细胞器.

3. Cytosol
• Contains water, dissolved molecules
(inorganic salts, lipids, amino acids, nucleic
acids, enzymes etc.) and cytoskeleton.
• Site for metabolism by providing reactants
and suitable environmental conditions for
reactions to occurs.

4. Organelles
• Specialized subunit within a cell that
has a specific function
• Most organelles are bound by a lipid
membrane, except:
• Ribosome
• Centrosome
• Cytoskeleton
Examples of membrane protein GFP-fusion localization in S. cerevisiae as
monitored by confocal microscopy.

5. Organelles
Golgi apparatus
Golgi apparatus

6. Types of organelles
• Endoplasmic reticulum (ER) 内质
网
• Smooth ER
• Rough ER
• Ribosome
• Golgi apparatus
• Centrosome
• Lysosome
• Chloroplast
• Vacuole
• Mitochondrion
• Cytoskeleton
• Microfilament
• Intermediate filament
• Microtubule

7. 2.2.3.1 Organelles

8. Objectives
• Understanding the function of the organelles
• Know where those organelles are frequently found

9. ★★
★
★
★
★
★
★
★
☆
Plant cell organelles
★★ chloroplast
★ vacuole
★

10. The secretory pathway of protein

11. Ribosome
• Ribosome translate mRNA into polypeptide.
• Globular complexes of RNAs and proteins.
• May attached to the endoplasmic reticulum (form the rough ER), free –
flowing in the cytosol, or form polysome (polyribosome) 多核糖体.
• Polysome is formed when more than one ribosome is translating an
mRNA at the same time.

12. Endoplasmic reticulum (ER)
• A network of flattened sacs and branching
tubules that extends throughout the cytoplasm.
• Increase the membrane surface area
• More enzymes can be attached onto the surface –
more reactions can occur
• Rough ER
• It is directly continuous with the nuclear envelope.
• Its surface is covered with ribosomes.
• The ribosome produces protein that will be secreted.
• It is widely found in pancreatic or salivary gland cells.
• Smooth ER
• It is not stubbed with ribosomes.
• It synthesizes lipids, phospholipids, and steroids and
is commonly found in bones cells, liver cells, and
plant cells.
• It have other functions such as regulating calcium ion
concentration in muscle cells.

13. Golgi apparatus
• Name after Camillo Golgi, who identified
this structure.
• A series of flattened, stacked pouches.
• Function:
• Transportation, modification, and packaging
of proteins and lipids into vesicles for delivery
to targeted destinations, e.g. secretion.
• Formation of new cell wall during plant cell
division.
• Protein synthesis NOT happening here.
Transmission electron micrograph (TEM) of Golgi apparatus
from a Chlamydomonas sp. alga.

14. The secretory pathway of protein
Secretory vesicles
Transport vesicles

15. Quiz
• What is Ted?
A. Endoplasmic reticulum
B. Smooth endoplasmic reticulum
C. Rough endoplasmic reticulum
D. Ribosome
E. Golgi apparatus

16. Quiz
• The organelle functions to package and deliver proteins:
A. lysosome
B. endoplasmic reticulum
C. mitochondrion
D. Golgi apparatus

17. Quiz
• Which structure is directly responsible for the formation of proteins
within the cell.
A. lysosomes
B. vacuoles
C. endoplasmic reticulum
D. ribosomes

18. Lysosome
• Lyso (Greek lysis: loosening,
releasing) + -some
formation of adjectives
• Vesicles that contain hydrolytic
enzymes.
• Decompose/break down
substances.
• Phagocytosis 吞噬作用 - fuse with
food vacuoles and digest food
obtained from endocytosis
(pinocytosis or phagocytosis)
• Autophagy 自体吞噬 - destroys old
and useless organelles.

19. Mitochondrion
• pl. mitochondria, Greek mitos
‘thread’ + khondrion (diminutive
of khondros ‘granule’)
• Carry out aerobic respiration
有氧呼吸.
• Provide energy for cell activities.
• Enclosed in a double bilayer
membrane (four layers).
• The inner membrane that extends inside and
folds into cristae (sg. crista)
• to increase the surface area of inner membrane
for embedment of enzymes that catalyze
respiration reactions.
• The cristae contain a fluid matrix, dissolved
with proteins, DNA, RNA, and ribosome.

20. Quiz
• This organelle is responsible for destroying worn-out cell parts:
A. lysosomes
B. mitochondrion
C. golgi apparatus
D. ribosomes

21. Quiz
Tour de France winner Greg Lemond
retired from competitive cycling when
he was diagnosed with a disorder that
prevented his cells from producing
sufficient energy for vigorous activity.
Which organelle was the source of his
malady?
A. The structure labeled "E"
B. The structure labeled "C"
C. The structure labeled "D"
D. The structure labeled "B"
E. The structure labeled "A"

22. Quiz
• The antibiotic tetracycline interferes with the function of bacterial
ribosomes. Because bacterial ribosomes are different from the
ribosomes in human cells, taking tetracyline only stops
A. the storage of water in bacterial cells
B. the production of bacterial protein
C. the formation of the bacterial cell wall
D. the processing and transport of lipids in the bacterial cell

23. Cytoskeleton
• Three types of
cytoskeleton:
• Microfilament (actin
filament) – thinnest
• Intermediate filament
• Microtubule – thickest
• Functions:
• Maintaining cell shape
• Change the shape of the
cell
• Allow movement of the
cell and the organelles
Bovine pulmonary artery endothelial cells.
Blue = nucleus, green = microtubule,
red = microfilament.

24. Centrosome
• Latin centrum 'center' + Greek sōma
'body‘
• Found in animal cells and lower plants
cells
• Generally located near the nucleus
• Composed of two perpendicularly
arranged centrioles and their associate
molecules.
• Organizing centre for microtubule (a
type of cytoskeleton)
• Cell division (guide the alignment of
chromosome and pull the chromosome
into daughter cells).
• Synthesis of cilia (sg. cilium) 纤毛 and
flagella (sg. flagellum) 鞭毛 .
EM micrograph
showing two centrioles
in cross section and
longitudinal section.
The triplet nature of
the centriole wall and
its nine-fold symmetry
can be seen clearly.
Scale bar: 100 nm.

25. Chloroplast
• Found in land plants, algae,
cyanobacteria, some protists.
• Important for photosynthesis.
• Enclosed in a double bilayer membrane
(four layers).
• Within chloroplast, thylakoids, arranged
in grana (sg. granum) stacks, are
suspended in stroma.
• Photosynthetic pigments such as
chlorophyll a, chlorophyll b, carotene,
xanthophyll etc. are found on the
thylakoid membrane.
• Stroma contains a small amount of DNA
and RNA and ribosome.

26. Vacuole
• A large Fluid-filled sac inside the cytoplasm of
plant cells.
• Tonoplast is the lipid bilayer membrane of
vacuole.
• Cell sap the cellular fluid inside the vacuole.
• Cell sap may contain high concentration of
saccharide, inorganic salts, pigment, and
protein etc.
• Function includes:
• Storage of waste products, water, nutrients.
• Regulate cell conditions such as maintaining turgor
pressure to ensure the cell keep swelling

27. Quiz
The structure labeled "G" has the
function of
A. converting food energy to ATP
B. storage and support
C. transporting proteins
produced by the attached
ribosomes
D. converting sunlight to energy

28. Fantastic organelles and where to find them
Organelles Function Abundant in Plant Animal
Rough ER Attached ribosomes produce proteins that will
be secreted
• Pancreatic cells
• Secretary cells in salivary gland
✔ ✔
Smooth ER Synthesizes lipids, phospholipids, and steroids • Bones cells
• Liver cells
✔ ✔
Ribosome Translate mRNA into polypeptide • Pancreatic cells
• Secretary cells in salivary gland
✔ ✔
Golgi apparatus Transportation, modification, and packaging of
proteins and lipids into vesicles;
formation of new cell wall during plant cell
division.
• Pancreatic cells
• Secretary cells in salivary gland
• Plant cells
✔ ✔
Mitochondria The powerhouse of the cell;
Produce ATP
• Skeletal muscle cells
• Liver cells
✔ ✔
Cytoskeleton
(microtubule,
intermediate
filament,
microfilament)
Maintaining cell shape;
Allow movement of the cell and the organelles
• All cells ✔ ✔

29. Fantastic organelles and where to find them
Organelles Function Abundant in Plant Animal
Centrosome Organizing centre for
microtubule
• Cell division
• Synthesis of cilia (sg.
cilium) and flagella (sg.
flagellum)
• One pair of centriole in each animal cell ✔
Lysosome Contain hydrolytic enzymes
that decompose/break down
substances
• Macrophage (a type of white blood cell) ✔
Chloroplast Photosynthesis • Leaf mesophyll cell ✔
Vacuole Storage,
Maintain hemeostasis
• Most plant cells ✔

30. Quiz
• Identify the organelle pictured.
A. organelle
B. chloroplast
C. endoplasmic reticulum
D. Golgi apparatus
E. mitochondria

31. Quiz
• Name the organelles.