Introduction to Biochemistry (L7) - Past Paper

Introduction to medicine {L7} SHAWABKEH Intro to Biochemistry !!!‫ﻓﻲ ھﺎي اﻟﻣﺣﺎﺿرة ﺑدﻧﺎ ﻧدرس ﻋن ﻣﻘدﻣﺔ ﻟﻣﺎدة رح ﻧدرﺳﮭﺎ ﺑﺎﻟﻔﺻل اﻟﺟﺎي ﻓرﻛز ﻣﻌﻲ ﻣزﺑوط‬ D...

Introduction to medicine {L7} SHAWABKEH Intro to Biochemistry !!!‫ﻓﻲ ھﺎي اﻟﻣﺣﺎﺿرة ﺑدﻧﺎ ﻧدرس ﻋن ﻣﻘدﻣﺔ ﻟﻣﺎدة رح ﻧدرﺳﮭﺎ ﺑﺎﻟﻔﺻل اﻟﺟﺎي ﻓرﻛز ﻣﻌﻲ ﻣزﺑوط‬ Definition of biochemistry: The study of chemical processes in living organisms. The study of structure, functions and properties of biomolecules..‫اﻟﻤﻌﺮﻓﺔ ﺑﻌﻠﻢ اﻟﻜﯿﻤﯿﺎء اﻟﺤﯿﻮﯾﺔ أﺳﺎﺳﯿﺔ ﻟﺠﻤﯿﻊ اﻟﻌﻠﻮم اﻟﺤﯿﺎﺗﯿﺔ‬ A Knowledge of Biochemistry is Essential to All life Sciences Immunology) Biomolecules compounds or molecules produced by living organisms, can be;.‫الجزيئات الكبيرة‬ Macromolecules: proteins, lipids, carbohydrates, and nucleic acids.‫اﻟﺠﺰﯾﺌﺎت اﻟﺼﻐﯿﺮة‬ Micro-molecules: Amino Acids (AA), nucleotides, monosaccharides…etc. ‫عضوية‬ Organic: carbon-based molecules, larger and more complex than non organic. ‫غير عضوية‬ Non-organic: metals, water Macromolecules: Macromolecule Building Block Main function (‫ﻣﺼﺪر ﻟﻠﻄﺎﻗﺔ )ﻟﻼﺣﺘﯿﺎﺟﺎت ﻗﺼﯿﺮة اﻟﻤﺪى‬ Carbohydrates Monosaccharides Energy Source (Short-term demand) Proteins Amino Acids Cell structure and function ‫ﺑﻨﯿﺔ ووظﯿﻔﺔ اﻟﺨﻠﯿﺔ‬ (‫حتياجات طويلة ا?دى‬:‫مصدر للطاقة )ل‬ Lipids Fatty acids and glycerol Energy source (Long-term demands) Nucleic acids Deoxy/Ribo-nucleotides Genetic and hereditary information ‫اﻟﻤﻌﻠﻮﻣﺎت اﻟﺠﯿﻨﯿﺔ واﻟﻮراﺛﯿﺔ‬ Carbohydrates ”‫ وھﻲ ﺣﺮﻓﯿﺎ ً “ھﯿﺪرات اﻟﻜﺮﺑﻮن‬،‫ھﻲ أﻛﺜﺮ اﻟﺠﺰﯾﺌﺎت اﻟﻌﻀﻮﯾﺔ وﻓﺮة ﻓﻲ اﻟﻄﺒﯿﻌﺔ‬ - They are the most abundant organic molecules in nature, they are literally “hydrate of carbon”. - Glucose is the most important carbohydrate. - Chemical formula: (CH2O)n, where n equals 3 or more. - Carbohydrates are formed by green plants from carbon dioxide and water during the process of photosynthesis; plants capture the energy in sunlight and transform it to the chemical bonds within carbohydrates. ‫ﺗﺘﻜﻮن اﻟﻜﺮﺑﻮھﯿﺪرات ﺑﻮاﺳﻄﺔ اﻟﻨﺒﺎﺗﺎت اﻟﺨﻀﺮاء ﻣﻦ ﺛﺎﻧﻲ أﻛﺴﯿﺪ اﻟﻜﺮﺑﻮن واﻟﻤﺎء ﺧﻼل ﻋﻤﻠﯿﺔ اﻟﺘﻤﺜﯿﻞ اﻟﻀﻮﺋﻲ؛ ﺣﯿﺚ ﺗﻠﺘﻘﻂ اﻟﻨﺒﺎﺗﺎت اﻟﻄﺎﻗﺔ ﻣﻦ ﺿﻮء اﻟﺸﻤﺲ وﺗﺤﻮﻟﮭﺎ إﻟﻰ اﻟﺮواﺑﻂ اﻟﻜﯿﻤﯿﺎﺋﯿﺔ داﺧﻞ اﻟﻜﺮﺑﻮھﯿﺪرات‬ ▪ The smallest molecule to be called a carbohydrate consists of 3 carbons, i.e. Glyceraldehyde (C3H6O3). ▪ Q: how many hydrogens in a carbohydrate molecule that has 7 carbons? 14 Hydrogens. Carbohydrates can be: Monosaccharides Disaccharides Oligosaccharides Polysaccharides Simple sugar 2 monosaccharides 3 to10 monosacchrides More than 10  Carbohydrate functions: ▪ Provide significant fraction of dietary calories for most organisms (4kcal\g) ( ‫ﻈﻏﻢﺮام‬/‫ﯾﺔﻛﯿاﻠﻟﻮﻐﺬاﻛﺋﺎﯿﻟﺔﻮ ﻟرﻤيﻌ‬4‫ﺗﻮﻓﺮ ﺟﺰًءا ﻛﺒﯿًﺮا ﻣﻦ ااﻟﻟﻜﺎﺴﺋﻌﻨﺎﺮاتتاﻟاﻟﺤﯿﺤﺔﺮا)ر‬ ▪ Act as a storage form of energy in the body ‫ﺗﻌﻤﻞ ﻛﻮﺳﯿﻠﺔ ﻟﺘﺨﺰﯾﻦ اﻟﻄﺎﻗﺔ ﻓﻲ اﻟﺠﺴﻢ‬ ▪ Structure of nucleic acids (i.e. Ribose and Deoxyribose) (‫ﺗﺪﺧﻞ ﻓﻲ ﺗﺮﻛﯿﺐ اﻷﺣﻤﺎض اﻟﻨﻮوﯾﺔ )ﻣﺜﻞ اﻟﺮﯾﺒﻮز واﻟﺪﯾﺄوﻛﺴﻲ رﯾﺒﻮز‬ ▪ Cell membrane components that mediate some intercellular communication (i.e. glycoprotein) ▪ Serve as a structural component of many organisms (i.e. chitin in insect’s exoskeleton and cellulose of plants) (‫ﺗﻌﻤﻞ ﻛﻌﻨﺼﺮ ﺑﻨﯿﻮي ﻟﻠﻌﺪﯾﺪ ﻣﻦ اﻟﻜﺎﺋﻨﺎت اﻟﺤﯿﺔ )ﻣﺜﻞ اﻟﻜﯿﺘﯿﻦ ﻓﻲ اﻟﮭﯿﻜﻞ اﻟﺨﺎرﺟﻲ ﻟﻠﺤﺸﺮات واﻟﺴﻠﯿﻠﻮز ﻓﻲ اﻟﻨﺒﺎﺗﺎت‬ (‫ﺗﺸﻜﻞ ﻣﻜﻮﻧﺎت ﻓﻲ ﻏﺸﺎء اﻟﺨﻠﯿﺔ اﻟﺘﻲ ﺗﺴﮭﻢ ﻓﻲ اﻻﺗﺼﺎل ﺑﯿﻦ اﻟﺨﻼﯾﺎ )ﻣﺜﻞ اﻟﺠﻠﯿﻜﻮﺑﺮوﺗﯿﻦ‬ Monosaccharides The simplest carbohydrates are called monosaccharides. (Examples: Glucose, galactose, fructose) Most basic units (monomers) of carbohydrates. Have a linear and unbranched carbon skeleton with one carbonyl (C=O) functional group, and one hydroxyl (OH) group on each of the remaining carbon atoms. Naming of Monosaccharides (according to number of carbons): ▪ 3 Carbons: Triose (i.e. glyceraldehyde) ▪ 4 Carbons: Tetrose (i.e. erythrose) ▪ 5 Carbons: Pentose (i.e. Ribose) ▪ 6 Carbons: Hexose (i.e. Glucose) Classification of monosaccharides according to the functional group: “Aldose-Ketose Isomerism” ▪Aldose: has an aldehyde functional group [Glyceraldehyde is the smallest]. ▪Ketose: has Ketone functional group [Dihydroxyacetone is the smallest]. Examples of important monosaccharides include: 1. Glucose (Aldose): is a monosaccharide containing six carbon atoms and an aldehyde group and is therefore an aldohexose. 2. Galactose (Aldose) 3. Fructose (Ketose) ✓ These hexoses are isomers and have physiologic importance. Methods of drawing monosaccharides structure: a. Fischer configuration: Linear form (A) b. Haworth configuration: Cyclic form (B) Note: Glucose is an aldose hexose, with two anomers in Haworth configuration. ▪ β-Glucopyranose: If hydroxyl group on C#1 is on the same direction of HOCH2 on C#6. ▪ α-Glucopyranose: If hydroxyl group on C#1 is on the opposite direction of HOCH2 on C#6.  Hexoses of physiological importance: Note that fructose is Ketose, while glucose and galactose are aldose. Disaccharides They are two monosaccharides linked together by glycosidic bond. (Examples: Lactose, Sucrose, Maltose) ▪Lactose: ~Glucose and Galactose~ ▪Sucrose: Maltose: ~Β glycosidic bond~ ~Glucose and fructose~ ~Found in milk~ ~Two-glucose linked by ‫ﻣﻮﺟﻮدة ﻓﻲ اﻟﺤﻠﯿﺐ‬ ~Alpha glycosidic bond~ alpha (1-4) glycosidic bond ~ ~Found in plants and table ~ Found in wheat and corn~ sugar~ ‫ﻣﻮﺟﻮدة ﻓﻲ اﻟﻨﺒﺎﺗﺎت و ﺳﻜﺮ اﻟﻤﺎﺋﺪة‬ ‫ﻣﻮﺟﻮدة ﻓﻲ اﻟﻘﻤﺢ و اﻟﺬرة‬ Polysaccharides Non-sweet carbohydrates, called glycans. Large carbohydrates consist of many monosaccharides linked by glyosidic bonds. (Examples: Starch, glycogen, cellulose and chitin) Starch and glycogen:.‫~ ﺑﻮﻟﯿﻤﺮ ﻣﻦ اﻟﺴﻜﺮﯾﺎت اﻷﺣﺎدﯾﺔ‬ ▪ Polymer of monosaccharides ‫~ ﯾﺴﺘﺨﺪم ﻛﻤﺼﺪر ﻟﻠﻄﺎﻗﺔ )ﯾﺘﻢ ﺗﻔﻜﯿﻜﮫ ﻹطﻼق اﻟﺴﻜﺮﯾﺎت اﻷﺣﺎدﯾﺔ‬ ▪ Used as an energy source (cleaved to release monosaccharides) ‫~ اﻟﻨﺸﺎ ﻣﻮﺟﻮد ﻓﻲ اﻟﻨﺒﺎﺗﺎت‬ ▪ Starch is found in plants (‫~ اﻟﺠﻠﯿﻜﻮﺟﯿﻦ ﯾُﺨﺰن ﻓﻲ أﺟﺴﺎﻣﻨﺎ )اﻟﺒﺸﺮ‬ ▪ Glycogen is stored in our body (HUMANS) Cellulose and chitin: ▪ Cellulose is found in plants [Human are unable to digest it, because we don’t have the necessary enzymes] Repeated glucose units bonded together by beta 1,4 bonds and Certain animals such as termites can digest cellulose, because bacterial enzyme are present in their gut. (‫ﯾﻮﺟﺪ اﻟﺴﻠﯿﻠﻮز ﻓﻲ اﻟﻨﺒﺎﺗﺎت )اﻟﺒﺸﺮ ﻏﯿﺮ ﻗﺎدرﯾﻦ ﻋﻠﻰ ھﻀﻤﮫ ﻷﻧﻨﺎ ﻻ ﻧﻤﺘﻠﻚ اﻹﻧﺰﯾﻤﺎت اﻟﻼزﻣﺔ ﻟﺬﻟﻚ‬ ▪ Chitin supports insect’s exoskeleton ‫اﻟﻜﯿﺘﯿﻦ ﯾﺪﻋﻢ اﻟﮭﯿﻜﻞ اﻟﺨﺎرﺟﻲ ﻟﻠﺤﺸﺮات‬ Proteins - They are polymers of amino acids monomers, linked by peptide bonds. - Proteins are polymers of amino acids; we have 20 standard amino acids found in mammalians. - A linear chain of amino acid residues is called a polypeptide. Two amino acids bind together in a dipeptide bond. Three amino acids bind together in a tripeptide bond. - Basic structure of Amino acids: These R-Groups can be small (i.e. hydrogen in glycine) or long chains NH+3 is called N-Terminus -COO is called C-Terminus bond between CO-NH in the middle is called peptide bond - The elements present in every amino acid are: carbon (C), hydrogen (H), oxygen (O), and nitrogen (N); in addition sulfur (S) is present in the side chains of cysteine and methionine, and selenium (Se) in the less common amino acid selenocysteine. - there are 300 di erent amino acid, only 20 of them form proteins. - Categories of amino acids: AA with Nonpolar side chains: Glycine, Alanine, Valine, Leucine, Isoleucine, Phenylalanine, Tryptophan, Methionine, Proline. AA with Uncharged polar side chain: ▪ Serine, Threonine, Tyrosine: Polar due to OH side chain. ▪ Asparagine, Glutamine: Polar due to NH2 side chain. ▪ Cysteine: Polar due to SH side chain. Acidic AA: PROTON DONAR /NEGATIVE CHARGE (Aspartic Acid, Glutamic Acid). Basic AA: PROTON ACCEPTOR / POSTIVE CHARGE (Histidine, Lysine, Arginine). - Organizational level of proteins: 1. Primary structure: - The linear sequence of linked amino acids. ‫اﻟﺘﺴﻠﺴﻞ اﻟﺨﻄﻲ ﻟﻸﺣﻤﺎض اﻷﻣﯿﻨﯿﺔ اﻟﻤﺮﺗﺒﻄﺔ‬ - The simplest level of protein structure. - Generate protein molecule with 3-dimentional shape which will determine the function of protein ‫ﯾﻨﺘﺞ ﺟﺰيء ﺑﺮوﺗﯿﻦ ذو ﺷﻜﻞ ﺛﻼﺛﻲ اﻷﺑﻌﺎد ﯾﺤﺪد وظﯿﻔﺔ اﻟﺒﺮوﺗﯿﻦ‬ - The sequence of amino acids is read from the N-terminus to Cterminus. 2. Secondary structure: i.e. Alpha helices or beta sheets. - The second level of protein structure. - The arrangement of amino acids in polypeptide chain. ‫ﺗﺮﺗﯿﺐ اﻷﺣﻤﺎض اﻷﻣﯿﻨﯿﺔ ﻓﻲ ﺳﻠﺴﻠﺔ اﻟﺒﻮﻟﻲ ﺑﺒﺘﯿﺪ‬ - local folded structures that form within a polypeptide due to interactions between atoms of the backbone. ‫اﻟﮭﯿﺎﻛﻞ اﻟﻤﻄﻮﯾﺔ اﻟﻤﺤﻠﯿﺔ اﻟﺘﻲ ﺗﺘﺸﻜﻞ داﺧﻞ اﻟﺒﻮﻟﻲ ﺑﺒﺘﯿﺪ ﻧﺘﯿﺠﺔ ﻟﻠﺘﻔﺎﻋﻼت ﺑﯿﻦ ذرات اﻟﻌﻤﻮد اﻟﻔﻘﺮي‬ - Both structures are held in shape by hydrogen bonds, which form between the carbonyl O of one amino acid and the amino H of another. 3. Tertiary Structure: - The overall three-dimensional structure of a polypeptide is called its tertiary structure. - The tertiary structure is primarily due to interactions between the R groups of the amino acids that make up the protein. - R group interactions that contribute to tertiary structure include hydrogen bonding, ionic bonding, dipole- dipole interactions, and London dispersion forces. ،‫ اﻟﺮواﺑﻂ اﻷﯾﻮﻧﯿﺔ‬،‫ اﻟﺘﻲ ﺗﺴﮭﻢ ﻓﻲ اﻟﺘﺮﻛﯿﺐ اﻟﺜﻼﺛﻲ ﺗﺸﻤﻞ اﻟﺮواﺑﻂ اﻟﮭﯿﺪروﺟﯿﻨﯿﺔ‬R ‫اﻟﺘﻔﺎﻋﻼت ﺑﯿﻦ ﻣﺠﻤﻮﻋﺎت‬ ‫اﻟﺘﻔﺎﻋﻼت ﺛﻨﺎﺋﯿﺔ اﻟﻘﻄﺐ‬ - Shape that determines function (rods or spherical). (‫اﻟﺸﻜﻞ اﻟﺬي ﯾﺤﺪد اﻟﻮظﯿﻔﺔ )ﻋﺼﻮي أو ﻛﺮوي‬ 4. Quaternary Structure: ‫اﻟﻌﺪﯾﺪ ﻣﻦ اﻟﺒﺮوﺗﯿﻨﺎت ﺗﺘﻜﻮن ﻣﻦ ﺳﻠﺴﻠﺔ ﺑﻮﻟﻲ ﺑﺒﺘﯿﺪ واﺣﺪة وﻟﺪﯾﮭﺎ ﻓﻘﻂ ﺛﻼﺛﺔ ﻣﺴﺘﻮﯾﺎت ﻣﻦ اﻟﺘﺮﻛﯿﺐ‬ - Many proteins are made up of a single polypeptide chain and have only three levels of structure. - More than one polypeptide chains (i.e. hemoglobin). - Functions of Proteins: Structural: i.e. Collagen Enzymatic: i.e. Trypsin Hormonal: i.e. Insulin Transport: i.e. Hemoglobin Defense: Immunoglobulins (Ig) “they make antibodies” Lipids (‫ھﻲ ﻣﺠﻤﻮﻋﺔ ﻏﯿﺮ ﻣﺘﺠﺎﻧﺴﺔ ﻣﻦ اﻟﺠﺰﯾﺌﺎت اﻟﻌﻀﻮﯾﺔ اﻟﻜﺎرھﺔ ﻟﻠﻤﺎء )ﻻ ﺗﺤﺐ اﻟﻤﺎء‬ - They are heterogenous group of hydrophobic organic molecules (don’t like water). - Lipids are compartmentalized (aggregate together because they are hydrophobic). - Many of the lipids inside our body consists of fatty acids - Functions: Long term energy storage ‫ﺗﺨﺰﯾﻦ اﻟﻄﺎﻗﺔ ﻋﻠﻰ اﻟﻤﺪى اﻟﻄﻮﯾﻞ‬ Components of cell membranes (i.e. phospholipids) (‫ﻣﻜﻮﻧﺎت أﻏﺸﯿﺔ اﻟﺨﻼﯾﺎ )ﻣﺜﻞ اﻟﻔﻮﺳﻔﻮﻟﯿﺒﯿﺪات‬ Protection and insulation ‫اﻟﺤﻤﺎﯾﺔ واﻟﻌﺰل‬ Hormone’s precursors ‫اﻟﺴﻼﺋﻒ اﻟﮭﺮﻣﻮﻧﯿﺔ‬ - Fatty acids consist of an alkyl chain with a terminal carboxyl group, CH3(CH2)nCOOH. - The carboxylic acid, which is polar, has a pKa of about 4.8. So it will be ionized at physiologic pH - Because we have hydrophilic and hydrophobic regions, fatty acids are considered amphipathic compounds. - Structure of lipids: ▪ Hydrocarbon chains can be unsaturated or saturated. ▪ Unsaturated (kink & double bond); trans or cis. - In humans the majority are saturated or mono-unsaturated – Fatty acids are stored primarily as esters of glycerol. ‫ ﺗُﺨﺰن اﻷﺣﻤﺎض اﻟﺪھﻨﯿﺔ ﺑﺸﻜﻞ رﺋﯿﺴﻲ ﻋﻠﻰ ﺷﻜﻞ إﺳﺘﺮات اﻟﺠﻠﺴﺮﯾﻦ‬- ‫ اﻷﻏﻠﺒﯿﺔ إﻣﺎ ﻣﺸﺒﻌﺔ أو أﺣﺎدﯾﺔ ﻋﺪم اﻟﺘﺸﺒﻊ‬،‫ﻓﻲ اﻟﺒﺸﺮ‬ - Palmitic acid  It contains 16 carbon atoms →entire region is the hydrocarbon chain.  Functional group is the carboxylic acid.  SO long chain fatty acids: considered hydrophobic. - Variations between Fatty Acids 1. The length of carbon chain -If length increase Melting point increase 2. Degree of saturation or unsaturation. ▪ Monounsaturated: have one double bond. ▪ Polyunsaturated: have two or more double bonds - In humans the majority saturated or monounsaturated. ‫ وأﺣﺪ اﻷﺳﺒﺎب اﻟﻤﮭﻤﺔ ھﻮ ﺗﺨﺰﯾﻦ اﻟﻄﺎﻗﺔ‬،‫ﺗﺴﺘﺨﺪم ﺧﻼﯾﺎﻧﺎ اﻷﺣﻤﺎض اﻟﺪھﻨﯿﺔ ﻷﺳﺒﺎب ﻣﺘﻨﻮﻋﺔ‬ - Our cells use fatty acids for a variety of reasons. One important reason is to store energy. - Triacylglycerol (are fatty acids that are stored primarily as esters of glycerol) Acylglycerol molecule is called: a) Fat: if it’s solid at room temperature. ‫ إذا ﻛﺎﻧﺖ ﺻﻠﺒﺔ ﻓﻲ درﺟﺔ ﺣﺮارة اﻟﻐﺮﻓﺔ‬:‫أ( اﻟﺪھﻮن‬ b) Oil: if it’s liquid at room temperature ‫ إذا ﻛﺎن ﺳﺎﺋﻼً ﻓﻲ درﺟﺔ ﺣﺮارة اﻟﻐﺮﻓﺔ‬:‫ب( اﻟﺰﯾﺖ‬ - The carboxyl group of the fatty acid loses its OH. Also, hydrogen atoms are lost from the hydroxyl groups of glycerol forming Triacylglycerol and water. Nucleic Acids - Include: Deoxyribonucleic acid (DNA) & Ribonucleic acid (RNA). - Function: storage & expression of genetic information. - DNA and RNA are polymers of nucleotides monomers Nucleobase (nitrogenous base) + Ribose sugar (pentose) = Nucleoside Nucleobase (nitrogenous base) + Ribose sugar + phosphate groups (1 to 3) = Nucleotide - Nucleobases (nitrogenous bases): A. Purines: Short name big structure (two rings) ▪ Adenine (A) and Guanine (G) B. Pyrimidines: long name small structure (one rings) ▪ Cytosine (C), Thymine (T), Uracil (U) ▪ Thymine is only found in DNA ▪ Uracil is only found in RNA Pentose sugar: - The sugar is linked to nitrogenous bases by glycosidic bond (N1 in Pyrimidines, N9 in Purines). - Ribose (RNA): has an oxygen at C2. - Deoxyribose (DNA); hasn’t O2 & gives deoxyribose more stability ‫ﺛﺒﺎت أﻛﺜﺮ‬ Phosphate group: - Added to C5 of the ribose sugar. - one p groupNMP(nucleoside monophosphate) - two p groupNDP(nucleoside diphosphate) - three p groupNTP(nucleoside triphosphate) DNA - DNA molecule is a double helix consisting of nucleotides connected together by a phosphodiester Bond. Nucleotide consists of ribose sugar that binds a phosphate group on its 5th carbon ,(5’end) and binds a nucleobase on its 1st carbon, this sugar has hydroxyl group on its 3rd (3'end) carbon (d). The sugar in RNA is ribose, and in DNA is deoxyribose. Phosphodiester bond forms between the first nucleotide hydroxyl group (3’) and the second nucleotides phosphate group (5’). The first nucleotide has free 5’ end, and the last nucleotide has a free 3’ end. In the Above figure (A), the white-yellow shadow is called the sugar-phosphate backbone. The nucleobases are found in inside of the double helix, sugar-phosphate backbone is outside. - The structure of DNA is a double helix: we have a strand that begins from 5’ to 3’, and a complementary strand Goes oppositely from 3’ to 5’. Adenine always binds Thymine with 2 hydrogen bonds. Guanine always binds Cytosine with 3 hydrogen bonds. Grooves: minor groove is narrow, major groove is wide. Antiparallel and complementary to each other. ‫ﻣﺘﻀﺎدان وﻣﺘﻜﺎﻣﻼن ﻟﺒﻌﻀﮭﻤﺎ اﻟﺒﻌﺾ‬ RNA - RNA is an unbranched polymeric form of nucleoside monophosphates (Nucleotides) joined together by 3’ to 5’ phosphodiester bonds. - Types of RNA: rRNA, tRNA and mRNA - RNA is a single strand - RNA is smaller than DNA - Central Dogma: ‫ﯾﺘﻢ ﻧﺴﺦ اﻟﻤﻌﻠﻮﻣﺎت اﻟﻮراﺛﯿﺔ وﻧﻘﻠﮭﺎ إﻟﻰ اﻟﺨﻼﯾﺎ اﻟﺒﻨﻮﯾﺔ ﻣﻦ ﺧﻼل اﻟﺤﻤﺾ اﻟﻨﻮوي‬ first DNA Replication: Genetic information is copied & transmitted to daughter cells through DNA second DNA Transcription: RNA synthesis from DNA template (DNA) ‫( ﻣﻦ ﻗﺎﻟﺐ اﻟﺤﻤﺾ اﻟﻨﻮوي‬RNA) ‫ﺗﺼﻨﯿﻊ‬ third RNA Translation: protein synthesis. ‫ﺗﺼﻨﯿﻊ اﻟﺒﺮوﺗﯿﻦ‬ Introduction to the main metabolic pathways in cell - The living cell is like energy factory; it uses energy and produces energy. - The change of free energy during a biological process is called ΔG. ΔG = Δ Products – Δ Reactants If we have positive ΔG(Endergonic) ‫ھﺬا ﯾﻌﻨﻲ أن طﺎﻗﺔ اﻟﻤﻨﺘﺞ أﻋﻠﻰ ﻣﻦ طﺎﻗﺔ اﻟﻤﺘﻔﺎﻋﻼت‬ - this means that the product energy is higher than the reactants energy. - Not spontaneously & it is endergonic (needs energy↑ ) ‫ﻟﯿﺴﺖ ﺗﻠﻘﺎﺋﯿﺔ وھﻲ ﺗﻔﺎﻋﻼت ﻣﺎﺻﺔ‬ (‫ﻟﻠﻄﺎﻗﺔ )ﺗﺤﺘﺎج إﻟﻰ طﺎﻗﺔ‬ if we have negative ΔG(Exergonic) ‫ھﺬا ﯾﻌﻨﻲ أن طﺎﻗﺔ اﻟﻤﺘﻔﺎﻋﻼت أﻋﻠﻰ ﻣﻦ طﺎﻗﺔ اﻟﻤﻨﺘﺠﺎت‬ - this means that the reactant energy is higher than the product energy. (‫ﺗﺤﺪث اﻟﺘﻔﺎﻋﻞ ﺗﻠﻘﺎﺋﯿًﺎ وھﻮ طﺎرد ﻟﻠﻄﺎﻗﺔ )ﻓﻘﺪان ﻟﻠﻄﺎﻗﺔ‬ - Reaction occurs spontaneously & it is exergonic (energy loss) ΔG is related directly to Enthalpy change (ΔH), and Entropy change (ΔS) ΔG = ΔH – ΔS Enthalpy is heat Entropy is the degree of disorder - Energy coupling: We use two reactions one is exergonic, and the other one is endergonic. We make both of them occur together, so the energy released from the first reaction can be used in the other one. ‫ﻧﻘﻮم ﺑﺎﺳﺘﺨﺪام اﻟﺘﻔﺎﻋﻠﯿﻦ ﻣًﻌﺎ ﺑﺤﯿﺚ ﯾﻤﻜﻦ اﺳﺘﺨﺪام اﻟﻄﺎﻗﺔ اﻟﻤﻨﻄﻠﻘﺔ ﻣﻦ اﻟﺘﻔﺎﻋﻞ اﻷول ﻓﻲ اﻟﺘﻔﺎﻋﻞ اﻵﺧﺮ‬ - Enzymes: Proteins that speed up metabolic reactions by lowering energy Barriers (energy of activation, not a ect ΔG). ‫ھﻢ ﻋﺒﺎرة ﻋﻦ ﻣﺤﻔﺰ ﯾﺴﺮع اﻟﺘﻔﺎﻋﻞ دون أن ﯾﺴﺘﮭﻠﻚ‬ They are a catalyst that speeds up a reaction without being consumed. Endergonic reactions need enzymes to occur. ‫اﻟﺘﻔﺎﻋﻼت اﻟﻤﺎﺻﺔ ﻟﻠﻄﺎﻗﺔ ﺗﺤﺘﺎج إﻟﻰ إﻧﺰﯾﻤﺎت ﻟﺘﺤﺪث‬ Exergonic reactions are accelerated by enzymes (lower energy barrier). All chemical reaction have an energy barrier separating the reactants and the products. This barrier is called the free energy of activation. Lowering the free energy of activationincrease the rate of reaction Transition state, where the high-energy intermediate is formed during the conversion of reactants to products. Do not change the free energy of reactants or products therefore. Do not affect ∆G and whether the reaction as is spontaneous or not Metabolism ‫ﻣﺠﻤﻮع ﺟﻤﯿﻊ اﻟﺘﻐﯿﺮات اﻟﻜﯿﻤﯿﺎﺋﯿﺔ اﻟﺘﻲ ﺗﺤﺪث ﻓﻲ اﻟﺨﻠﯿﺔ أو اﻷﻧﺴﺠﺔ أو اﻟﺠﺴﻢ‬ - Metabolism: the sum of all chemical changes occurring in cell, tissue, or the body. - In the metabolic pathway, the product of one reaction can be used as a substrate of another reaction. - Metabolic pathways can be: A. Anabolic: build macromolecules & need energy. ‫ ﺑﻨﺎء اﻟﺠﺰﯾﺌﺎت اﻟﻜﺒﯿﺮة وﯾﺤﺘﺎج إﻟﻰ طﺎﻗﺔ‬:‫اﻻﺑﺘﻨﺎﺋﻲ‬ B. Catabolic: degrade(break) macromolecules into smaller molecules& release energy (i.e. ATP) (ATP ‫ﺗﺤﻄﯿﻢ اﻟﺠﺰﯾﺌﺎت اﻟﻜﺒﯿﺮة إﻟﻰ ﺟﺰﯾﺌﺎت أﺻﻐﺮ وإطﻼق اﻟﻄﺎﻗﺔ )ﻣﺜﻞ‬ - ATP(adenosine triphosphate)energy currency of cell - Metabolic disease: A disease due to a metabolic disorder. ‫ﻣﺮض ﻧﺎﺗﺞ ﻋﻦ اﺿﻄﺮاب اﺳﺘﻘﻼﺑﻲ‬ A ects the ability of the cell to perform critical biochemical reactions. ‫ﯾﺆﺛﺮ ﻋﻠﻰ ﻗﺪرة اﻟﺨﻠﯿﺔ ﻋﻠﻰ ﺗﻨﻔﯿﺬ اﻟﺘﻔﺎﻋﻼت اﻟﺒﯿﻮﻛﯿﻤﯿﺎﺋﯿﺔ اﻟﺤﺮﺟﺔ‬ Usually occurs in the enzymes that control certain pathways. ‫ﯾﺤﺪث ﻋﺎدة ﻓﻲ اﻹﻧﺰﯾﻤﺎت اﻟﺘﻲ ﺗﺘﺤﻜﻢ ﻓﻲ ﻣﺴﺎرات ﻣﻌﯿﻨﺔ‬ Examples: ▪ Insulin insu iciency a ects glucose transport & metabolism, leading to diabetes ▪ Liver or pancreas abnormality ▪ Phenylketonuria (phenylalanine metabolism abnormality >> brain damage) ‫ ﻣﻤﺎ ﯾﺆدي إﻟﻰ ﻣﺮض اﻟﺴﻜﺮي‬،‫ﻧﻘﺺ اﻷﻧﺴﻮﻟﯿﻦ ﯾﺆﺛﺮ ﻋﻠﻰ ﻧﻘﻞ اﻟﺠﻠﻮﻛﻮز واﻻﺳﺘﻘﻼب‬ ‫ﺧﻠﻞ ﻓﻲ اﻟﻜﺒﺪ أو اﻟﺒﻨﻜﺮﯾﺎس‬ ‫اﻟﻔﯿﻨﯿﻞ ﻛﯿﺘﻮﻧﻮرﯾﺎ )ﺧﻠﻞ ﻓﻲ اﺳﺘﻘﻼب اﻟﻔﯿﻨﯿﻞ أﻻﻧﯿﻦ( ﯾﺆدي إﻟﻰ ﺗﻠﻒ اﻟﺪﻣﺎغ‬