1. 1 2- Proteins 1.A polypeptide عديد الببتيد is a polymer تجمع of amino acids الاحماض الامينية connected in a specific sequence تتابع محدد

2. 2  Function وظائف البروتينات 1.structural support, تدعيم 2.storage, تخزين 3.transport of other substances, نقل بعض المواد 4.intercellular signaling الإشارات بين الخلوية, 5. movement, الحركة 6. defense against microbes.الدفاع ضد الميكروبات 7.Some proteins works as enzymes البعض يعمل كإنزيمات  All protein are constructed from تتركب من 20 monomers, called amino acids.  Polymers of proteins are called polypeptides ببتيدات عديدة. 2-Proteins

3. 3 Side chain سلسلة جانبية Amino group Carboxyl group - Protein is a polymer of amino acidsتجمع من الاحماض الامينية General Formula of the Amino Acid:التركيب الاساسي للحمض الاميني CHR N H H C OHOHOHOH O R - The side chain R links with ترتبط بـ different compounds - Differences in R groups produce the 20 different amino acids.

4. 4 The Peptide Bond الرابطة البيبتيدية Peptide bond formed between the carboxyl group of one amino acid and the amino group of the other by dehydrationنزع الماء. OHOHOHOH C C H R N H H O H CHR NHC OHOHOHOH O Peptide bond Dehydration نزع الماء Amino acids are joined together when a dehydration reaction removes a hydroxyl group from the carboxyl end of one amino acid and a hydrogen from the amino group of another. The resulting covalent bond is called a peptide bond.Amino acids are joined together when a dehydration reaction removes a hydroxyl group from the carboxyl end of one amino acid and a hydrogen from the amino group of another. The resulting covalent bond is called a peptide bond.

5. 5 3- Lipidsالدهون ; The Hydrophobic Molecules 1.Fats store large amounts of energyالدهون – تخزن كميات من الطاقة 2.Phospholipids الدهون الفوسفاتية in cell membranes اغشية الخلايا 3.Steroids include cholesterolالاسترويدات مثل الكوليسترول 1.Fats store large amounts of energyالدهون – تخزن كميات من الطاقة 2.Phospholipids الدهون الفوسفاتية in cell membranes اغشية الخلايا 3.Steroids include cholesterolالاسترويدات مثل الكوليسترول

6. 6 they do not have polymers. لا تحتوي تجمعاتthey do not have polymers. لا تحتوي تجمعات they all have no affinity for water لا تـَمتزج بالماء.they all have no affinity for water لا تـَمتزج بالماء. –This is because their structures have non-polar covalent bonds. روابط غير قطبية A fat is constructed fromتتكون من two kinds نوعانof smaller moleculesالجزيئات الاصغر, glycerol الجليسرولand fatty acids.A fat is constructed fromتتكون من two kinds نوعانof smaller moleculesالجزيئات الاصغر, glycerol الجليسرولand fatty acids أحماض دُهنية. 1)- Fats:الدهون

7. 7 A fat is composed of three fatty acids linked with one glycerol molecule. Fats are classified into Saturated مشبع and Un-saturated غير مشبع fats OHOH H H C C C C C C H H H H H H H H H O O C C C H H H H OHOH OHOH H H Dehydration Fatty Acid Glycerol Glycerol consists of a three C skeleton with an OH group attached to each C. A fatty acid consists of a carboxyl group ( COOH ) attached to a long carbon skeleton, often 16 to 18 carbons long. Ester link

8. 8 Fatty acids may vary تختلف in length (number of carbons) and in the number and locations of double bonds. carbon-carbon double bonds مشبع H –If there are no carbon-carbon double bonds, then the molecule is a saturated fatty acid مشبع (has H at every possible position). one or more carbon-carbon double bonds حامض دهنىغير مشبع HIf there are one or more carbon-carbon double bonds, then the molecule is an unsaturated fatty acid حامض دهنى غير مشبع - formed by the removal of H atoms from the carbon skeleton.

9. 9 A)- Saturated Fats الدهون المشبعة The Fatty acid components are saturated (there is no double bonds between the carbons. All C are linked with H. Thus, it is saturated with H. Most animal fats are saturated. * They are solid at room temperature. * Saturated fats-rich diet results in Atherosclerosis التصلب الشريانى. These double bonds are formed by the removal of H atoms. * Most vegetable fats (oils) and fish fats are unsaturated. * They are liquid at room temperature. * They can be synthetically converted to saturated (solid) by adding H (Hydrogenation الهَدْرَﭽـَة). B)- Un-saturated Fats الغيرمشبعةالدهون B)- Un-saturated Fats الغير مشبعة الدهون

10. 10 Phospholipids have two fatty acids attached to glycerol and a phosphate group at the third position.Phospholipids have two fatty acids attached to glycerol and a phosphate group at the third position. –The phosphate group carries a negative charge –The phosphate group carries a negative charge. 2)- Phospholipids; Are major components of cell membranes The fatty acid tails are hydrophobic, but the phosphate group and its attachments form a hydrophilic head.The fatty acid tails are hydrophobic, but the phosphate group and its attachments form a hydrophilic head. Thus, it is amphipathicThus, it is amphipathic

11. 11 Steroids are lipids with a carbon skeleton consisting of four fused ملتحمة carbon rings.Steroids are lipids with a carbon skeleton consisting of four fused ملتحمة carbon rings. –Different steroids are created by varying functional groups attached to the rings. 3)- Steroids: Include cholesterol and certain hormones Cholesterol, an important steroid, is a component in animal cell membranes.Cholesterol, an important steroid, is a component in animal cell membranes. Cholesterol is also the precursor المادة الخام from which all other steroids are synthesized. Cholesterol is also the precursor المادة الخام from which all other steroids are synthesized. Many of these other steroids are hormones, including the vertebrate sex hormones. Many of these other steroids are hormones, including the vertebrate sex hormones. While cholesterol is clearly an essential molecule, high levels of cholesterol in the blood may contribute to Atherosclerosis تصلب الشراييت While cholesterol is clearly an essential molecule, high levels of cholesterol in the blood may contribute to Atherosclerosis تصلب الشراييت

12. 12 F a t s (Composed of Lipids) SaturatedSaturatedUnsaturatedUnsaturatedPhospholipidsPhospholipids Animal FatsVegetable Fats Bi-layer of cell membrane Hydrogenationهَـدْرَﭽـَــــــــة SteroidsSteroids Sex Hormones & Cholesterol