B- Eukaryotic Cell

Fig. 7.11, Page 119 3)- The endoplasmic reticulum (ER) manufacturers membranes and performs many other biosynthetic functions The ER includes membranous tubulesThe ER includes membranous tubules There are two types of ER that differ in structure and function.There are two types of ER that differ in structure and function. 1.Smooth ER looks smooth ناعمة because it lacks ribosomes. 2.Rough ER looks rough خشنة because ribosomes ( bound ribosomes ) are attached to its outside.

The smooth ER:The smooth ER: الشبكة الإندوبلازمية الناعمة الهرمونات الجنسية - It synthesizes lipids دهون (oils, phospholipids, and steroids) including the sex hormones الهرمونات الجنسية. توجد بكثرة إبطال الأثر السام المخدراتالسموم - Extensive توجد بكثرة in the liver, it helps detoxify إبطال الأثر السام drugs المخدرات and poisons السموم The rough ER:The rough ER: الشبكة الإندوبلازمية الخشنة متوفرة - is especially abundant متوفرة in those cells that secrete proteins تفرز البروتيناتas it contains ribosomes.

أوعية ناقلة تطويرMany transport vesicles أوعية ناقلة from the ER travel to the Golgi apparatus for modification تطوير of their contents. تصنيع تغليفتـَجْهيز PackagingThe Golgi function is manufacturing تصنيع, warehousing تغليف, sorting تـَجْهيز (Packaging), and shipping نقل materials to outside the cell. specialized for secretion المتخصصة في الإفرازThe Golgi apparatus is especially extensive in cells specialized for secretion المتخصصة في الإفراز. 4)- Golgi apparatus: finishes, sorts تـُجَهز, packaging and ships تغلف وتنقل cell products

Fig. 7.12, Page 120 وعاء ناقل

lysosomeThe lysosome is a membrane-bounded sac كيسof enzymes that digests macromolecules. 5)- Lysosomes الأجسام المُحللة are digestive components Fig. 7.13a, Page 121

Lysosomal enzymes work best at pH = 5 (acidic). The lysosomal enzymes are synthesized by rough ER and then transferred to تنقل إلى the Golgi then to lysosomes. Function of Lysozomal enzymes 1)They hydrolyse يحلل proteins, fats, polysaccharides, and nucleic acids. الهضم الذاتى 2)Can destroy the cell by autodigestion (autophagy) الهضم الذاتى. الفجوة الغذائية 3)Can fuse with food vacuoles الفجوة الغذائية to digest food, (when a food item is brought into the cell by phagocytosis). recycling 4)Can digestتهضم another organelle. This process of autophagy called recycling which renews the cell Lysozomal enzymes

Fig. 7.14, Page 122

أوعـيةفجوات أكياس ذات أغشيةVesicles أوعـية and vacuoles فجوات are membrane-bound sacs أكياس ذات أغشية with varied functions. 1.Food vacuoles فجوة غذائية 1.Food vacuoles فجوة غذائية, from phagocytosis, fuse with lysosomes. 2.Contractile vacuoles فجوة منقبضة 2.Contractile vacuoles فجوة منقبضة, found in freshwater protists, pump excess water out of the cell. 3.Central vacuolesفجوة مركزية 3.Central vacuoles فجوة مركزية are found in many mature plant cells. 6)- Vacuoles: الفجوات وظائف متنوعةللحفاظ على الخلية 6)- Vacuoles: الفجوات have diverse functions وظائف متنوعة in cell maintenance للحفاظ على الخلية

Figs & 166, Page 123 الفجوة المركذية خلية نباتية خلية حيوانية

7)- Peroxisomes contain enzymes that transfer hydrogen from various substrates to oxygen Functions of peroxisomes (H 2 O 2 1- Hydrogen peroxide (H 2 O 2 ) is a poison, but the peroxisome has enzyme that converts H 2 O 2 to water. 2- Some peroxisomes break fatty acidsالأحماض الدهنية تكسرdown to smaller molecules that are transported to لإنتاج الطاقة mitochondria for fuel لإنتاج الطاقة. 3- They detoxify يبطل المفعول السُّمى alcohol and other harmful compounds. Thus, it exists liver cells extensively in the liver cells

Mitochondria: Thy are the main energy producers منتجي الطاقة of cells a 8)- Mitochondria: Thy are the main energy producers منتجي الطاقة of cells as they make energy الطاقة that cells can use for work. MitochondriaMitochondria are the sites of cellular respiration, تـُنتِج ATP هدم مصادرgenerating تـُنتِج ATP from the catabolism هدم of sugars, fats, and other fuels مصادر طاقة in the presence of oxygenفي وجود الأكسجين. Almost all eukaryotic cells have mitochondria. Mitochondria are mobileمتحركة and move around the cell along tracksمسارات in the cytoskeletonهيكل الخلية.

Mitochondria نتوءاتMitochondria have a smooth outer membrane غشاء خارجي ناعم and a highly folded inner membrane غشاء داخلي منثنيforming cristae نتوءات. mitochondrial matrixThe inner membrane enclosesيحيط the mitochondrial matrix, a fluid- filled space with DNA, ribosome, and enzymes. Fig. 7.17, Page 124