1. عضيــات الخليـــــــــة
The Cell Organelles
عضيــات الخليـــــــــة

2. نوية النواة الجدار النووى سوط حركي جسم مركزي ريبوسوم جهاز جولـﭽـى
المادة الوراثية
الشبكة الإندوبلازمية
نوية
النواة
الجدار النووى
سوط حركي
جسم مركزي
ريبوسوم
جهاز جولـﭽـى
حلمات دقيقة
غشاء بلازمى
ميتوكوندريا
جسم مُحلل
الهيكل الخلوي

3. نوية النواة الجدار النووى سوط حركي جسم مركزي ريبوسوم جهاز جولـﭽـى
المادة الوراثية
الشبكة الإندوبلازمية
نوية
النواة
الجدار النووى
سوط حركي
جسم مركزي
ريبوسوم
جهاز جولـﭽـى
حلمات دقيقة
غشاء بلازمى
ميتوكوندريا
جسم مُحلل
الهيكل الخلوي

4. 1. The nucleus The nucleus contains most of the genes in an eukaryotic cell The nucleus averages about 5 µm in diameter.
a. Nuclear envelope
Structure:
The nucleus is separated from the cytoplasm by a double membrane غشاء مزدوج.
Where the double membranes are fused, a pore ثقوب is formed
Functions:
1. Pores allows macromolecules to pass through.
2. The nuclear membrane الغلاف النووى is maintaining the
shape of the nucleus

6. b. Chromatin
Structure:
Within the nucleus, the DNA and associated proteins are organized into fibrous material, chromatin.
At the time of division, the chromatin fibers coil up تلتف to be seen as separate structures, chromosomes.

7. Each eukaryotic species has a characteristic number of chromosomes رقم مُمَيـٍز من الكروموسومات.
- A typical human cell has 46 chromosomes (23 pairs), but sex cells (ovum and sperm) have only 23 chromosomes.

8. b. Chromatin 1. Chromatin have genes that determine
Functions:
1. Chromatin have genes that determine
تحدد the general characters الصفات العامة
of organism.
2. The nucleus directs protein synthesis
by synthesizing messenger RNA(mRNA).
The mRNA travels to the cytoplasm and combines with ribosome where the primary structure of a specific protein is formed.

9. c. Nucleolus ***
Nucleolus is a dark region involved in the production of ribosomes.

10. 2. Ribosomes *** Ribosomes contain ribosomal RNA (rRNA) and protein.
A ribosome is composed of two subunits وحدتين that combine تتحد to direct protein synthesis تخليق البروتين.
مرتبطة
حرة

11. In the nucleolus, ribosomal RNA (rRNA) is synthesized into ribosomal subunits (rRNA + proteins).
The subunits pass from the nuclear pores to the cytoplasm where they combine to form ribosomes.
Cell types that synthesize large quantities of
proteins have large numbers of ribosomes (e.g.
pancreas)

12. Ribosomes are 2 types:-
Free ribosomes are suspended معلق in the cytosol and synthesize proteins that function within the cytosol.
Bound ribosomes are attached to ملتصق بـ the outside of the endoplasmic reticulum.
This type of ribosomes synthesize proteins that are either included into membranes or for secretion outside the cell.

13. 3- The Endomembrane System
The endoplasmic reticulum manufactures membranes and performs many other biosynthetic functions
The Golgi apparatus finishes, sorts, and ships cell products
The Lysosomes are digestive compartments
The Vacuoles have diverse functions in cell maintenance

14. a)- Endoplasmic reticulum
The ER includes membranous tubules
ER manufacturers membranes and performs many other biosynthetic functions

15. a)- Endoplasmic reticulum
There are two types of ER that differ in structure and function.
Smooth ER looks smooth because it lacks ribosomes.
Rough ER looks rough خشنة because ribosomes (bound ribosomes) are attached to its membranes.

16. a)- Endoplasmic reticulum
The smooth ER:
- It is rich in enzymes and
plays a role in metabolic processes.
- Its enzymes synthesize lipids (oils, phospholipids, and steroids, including the sex hormones الهرمونات الجنسية).
- Extensive in the liver ( it helps to detoxify drugs and poisons )

17. a)- Endoplasmic reticulum
The rough ER: it contains ribosomes
- is the main site of protein synthesis.
- It is especially abundant متوفرة in those cells that secrete proteins.
- These secretory proteins are packaged in transport vesicles that carry them to other parts of the endomembrane system

18. Synthesis and packaging of a secretory protein by the rough ER
Transport vesicle
buds off
تبرعم الحويصلة الناقلة 4
Ribosomeرايبوزوم
Secretory
Protein inside
transport vesicle
بروتين افرازي في داخل
حويصلة ناقلة 3
Sugar chain
سلسلة سكر 1
Figure 4.9B Synthesis and packaging of a secretory protein by the rough ER.
Glycoprotein
بروتين سكري 2
Polypeptide
عديد البيبتيد
Rough ER
الشبكة الاندوبلازمية المحببة
Synthesis and packaging of a secretory protein by the rough ER
بناء وتغليف البروتين الإفرازي في الشبكة الاندوبلازمية المحببة

19. Golgi apparatus also manufactures polysaccharides.
b)- Golgi apparatus:
The Golgi apparatus function is manufacturing تصنيع, sorting, packaging تغليف, and shipping materials to outside the cell.
Many transport vesicles حويصلات ناقلة from the ER travel to the Golgi apparatus for modification تعديلof their contents.
Golgi apparatus also manufactures polysaccharides.
The Golgi apparatus is extensive specially in secretory cells.

20. وعاء ناقل

21. c)- Lysosomes الأجسام المُحللة
The lysosome is a membrane-bounded sac of enzymes that digests macromolecules.

22. The lysosomal enzymes and membrane are synthesized by rough ER and then transferred to the Golgi apparatus and then to lysosomes.
Lysosomal enzymes can hydrolyse proteins, fats, polysaccharides, and nucleic acids.
These enzymes work best at pH = 5 (acidic).
While rupturing إنفجار lysosomes can destroy the cell by autodigestion (autophagy) الهضم الذاتى.

23. Lysosomes can fuse with food vacuoles الفجوة الغذائية to digest food, (when a food item is brought into the cell by phagocytosis).
Lysosomes can also fuse with another organelle or part of the cytosol. This process of autophagy called recycling which renews the cell

24. Lysosome fusing with a food vacuole and digesting food
Digestive
Enzymes
انزيمات هاضمة
Lysosomeجسم هاضم
Plasma membrane
الغشاء البلازمي
Figure 4.11A Lysosome fusing with a food vacuole and digesting food.
Lysosome fusing with a food vacuole and digesting food
الجسم الهاضم أثناء اندماجه مع فجوة غذائية و قيامه بهضم الغذاء

25. Lysosome fusing with a food vacuole and digesting food
Digestive
Enzymes
انزيمات هاضمة
Lysosomeجسم هاضم
Plasma membrane
الغشاء البلازمي
Food vacuole
فجوة غذائية
Figure 4.11A Lysosome fusing with a food vacuole and digesting food.
Lysosome fusing with a food vacuole and digesting food
الجسم الهاضم أثناء اندماجه مع فجوة غذائية وقيامه بهضم الغذاء

26. Lysosome fusing with a food vacuole and digesting food
Digestive
Enzymes
انزيمات هاضمة
Lysosomeجسم هاضم
Plasma membrane
الغشاء البلازمي
Food vacuole
فجوة غذائية
Figure 4.11A Lysosome fusing with a food vacuole and digesting food.
Lysosome fusing with a food vacuole and digesting food
الجسم الهاضم أثناء اندماجه مع فجوة غذائية وقيامه بهضم الغذاء

27. Lysosome fusing with a food vacuole and digesting food
Digestive
Enzymes
انزيمات هاضمة
Lysosomeجسم هاضم
Plasma membrane
الغشاء البلازمي
Food vacuole
فجوة غذائية
Digestion
الهضم
Figure 4.11A Lysosome fusing with a food vacuole and digesting food.
Lysosome fusing with a food vacuole and digesting food
الجسم الهاضم أثناء اندماجه مع فجوة غذائية وقيامه بهضم الغذاء

28. Lysosome fusing with vesicle containing damaged
damaged mitochondrion
حويصلة تحتوي على ميتوكوندريا تالفة
Figure 4.11B Lysosome fusing with vesicle containing damaged organelle and digesting and recycling its contents.
Lysosome fusing with vesicle containing damaged
organelle and digesting and recycling its contents
الجسم الهاضم أثناء اندماجه مع فجوة تحتوي
عضيات تالفة ليقوم بهضمها وإعادة تدويره محتوياتها

29. Lysosome fusing with vesicle containing damaged
damaged mitochondrion
حويصلة تحتوي على ميتوكوندريا تالفة
Figure 4.11B Lysosome fusing with vesicle containing damaged organelle and digesting and recycling its contents.
Lysosome fusing with vesicle containing damaged
organelle and digesting and recycling its contents
الجسم الهاضم أثناء اندماجه مع فجوة تحتوي
عضيات تالفة ليقوم بهضمها وإعادة تدوير محتوياتها

30. Lysosome fusing with vesicle containing damaged
damaged mitochondrion
حويصلة تحتوي على ميتوكوندريا تالفة
Digestion
الهضم
Figure 4.11B Lysosome fusing with vesicle containing damaged organelle and digesting and recycling its contents.
Lysosome fusing with vesicle containing damaged
organelle and digesting and recycling its contents
الجسم الهاضم أثناء اندماجه مع فجوة تحتوي
عضيات تالفة ليقوم بهضمها وإعادة تدوير محتوياتها

31. d)- Vacuoles الفجوات
Vesicles and vacuoles are membrane-bound sacs أكياس ذات أغشية with varied functions.
Vacuoles have diverse functions in cell maintenance
Types of vacuoles :
Food vacuoles فجوة غذائية, from phagocytosis, fuse with lysosomes.
Contractile vacuoles فجوة منقبضة , found in freshwater protists, pump excess water out of the cell.
Central vacuoles فجوة مركزية are found in many mature plant cells.

32. Animal cell

34. Peroxisomes ( microbodies)
are organelles found in
virtually all eukaryotic cells.
Peroxisomes were identified as organelles by the Belgian cytologist Christian de Duve in 1967 after they had been first described by a Swedish doctoral student, J. Rhodin in 1954.

35. Functions: Peroxisomes :
1-A major function of the peroxisome is the breakdown of very long chain fatty acids through beta-oxidation to smaller molecules that are transported to mitochondria for fuel.

36. Peroxisomes :
2- They contain oxidative enzymes that transfer hydrogen from various substrates to oxygen
(An intermediate product of this process is hydrogen peroxide (H2O2), toxic سام but the peroxisome has another enzyme that converts H2O2 to water).
3- They detoxify alcohol and other harmful compounds. Thus, it exists extensively in the liver cells

37. Mitochondrion:
is a membrane-bound organelle found in most eukaryotic cells 
the main energy transformer of cells

38. Mitochondria have a smooth outer membrane and a highly folded inner membrane forming cristae نتوءات.
The inner membrane encloses the mitochondrial matrix, a fluid-filled space with DNA, ribosomes, and enzymes.

39. Mitochondrion
Mitochondria are the sites of cellular respiration, generating ATP (Adenosine TriPhosphate) from the catabolism هدم of sugars, fats, and other fuel sources in the presence of oxygen.
In addition to supplying cellular energy, mitochondria are involved in other tasks such as signaling, cellular differentiation, cell death, as well as the control of the cell cycle and cell growth.

40. THE CYTOSKELETON الهيكل الخلوي
Copyright © 2009 Pearson Education, Inc.

41. The Cytoskeleton الهيكل الخلوى
The cytoskeleton is a network of fibers extending throughout the cytoplasm
Functions:
The cytoskeleton organizes the structures and activities of the cell.
functions in cell motility.

42. Fibers of the cytoskeleton ألياف الهيكل الخلوي
Nucleus
نواة
Nucleus
نواة
Actin subunit
وحدة آكتين فرعية
Tubulin subunit
وحدة توبيولين فرعية
Fibrous subunits
وحدات ليفية فرعية
Figure 4.17 Fibers of the cytoskeleton : microfilaments are stained red (left), intermediate filaments are stained yellow-green (center), and microtubules are stained green (right).
7 nm
10 nm
25 nm
Microfilament
خيط دقيق
Intermediate filament
خيط متوسط
Microtubule
انيبية دقيقة
Fibers of the cytoskeleton
ألياف الهيكل الخلوي

43. Cytoskeleton Microfilaments Intermediate filaments Microtubules
Thick ( hollow tubes)
(resist compression)
Thin
(resist tension)
Middle
Responsible for cell motility )cilia & flagellum)
separation of chromosome during cell division.
Tracks for organelles movement
- Cell motility (muscle cell)
- Transport materials across the cell.
Reinforcing the cell shape
fixing position of organelles.

44. Cilia and Flagella
Microtubules are the central structural supports both cilia الأهداب and flagella الأسواط.
Both can move unicellular and small multicellular organisms by propelling water outside the organism.

45. الأهداب الموجودة على الخلايا المبطنة للقناة التنفسية
Ciliaأهداب
Figure 4.18A Cilia on cells lining the respiratory tract.
Cilia on cells lining the respiratory tract to sweep mucus of our lungs
الأهداب الموجودة على الخلايا المبطنة للقناة التنفسية

46. Undulating flagellum on a sperm cell سوط متموج على خلية الحيوان المنوي
Figure 4.18B Undulating flagellum on a sperm cell.
Undulating flagellum on a sperm cell
سوط متموج على خلية الحيوان المنوي

47. Both cilia and flagella have the same ultrastructure.
Both have a core of microtubules sheathed by the plasma membrane.
Nine doublets (9 + 2 pattern) of microtubules arranged around a pair at the center.
Flexible “wheels” of proteins connect outer doublets to each other and to the core.
- The outer doublets
are also connected
by motor proteins.
- The structure of cilium and flagellum is
identical to that of
centriole.

49. Cilia and flagella are formed of arms of a motor protein (dynein بروتين الداينين).
Addition of phosphate group from ATP to dynein and its removal causes conformation changes in the protein.
Dynein arms alternately grab, move, and release the outer microtubules.
Protein cross-links limit sliding and the force is expressed as bending.

50. So, They differ in their beating pattern
Cilia
Flagella
usually occur in large numbers on the cell surface.
move more like oars with alternating power and recovery strokes.
usually occur in just one or a few per cell.
have an undulatory movement.
So, They differ in their beating pattern

51. cilia
flagellum