Nutritional Biochemistry Lecture 2 PDF

Nutritional Biochemistry BIOCH 209 (BIOCH 209) Level 4 (2nd Year, 2nd Semester) Introduction Arafat Goja, PhD Lecture 2: Clinical Nutrition Department...

Nutritional Biochemistry BIOCH 209 (BIOCH 209) Level 4 (2nd Year, 2nd Semester) Introduction Arafat Goja, PhD Lecture 2: Clinical Nutrition Department January 20, 2025 Imam Abdulrahman Bin Faisal University 1  Topic to be covered in this lecture: Definition of Biochemistry and its importance. Understand why biochemistry is important in nutrition fields Understand Biochemistry of the molecules and their processing in the living cells Outline chemistry of carbohydrates, Lipids ( Fats/Oils) and Proteins. Describe Physical & chemical properties of carbohydrates, Lipids ( Fats/Oils) and Proteins The roles and fate of macronutrients: ✓ Carbohydrates ✓ Lipids ( Fats/Oils) ✓ Proteins 2  Biochemistry: Definition Biochemistry: Definition ✓ ‘’bios’’ Greek word which means “life” ✓ Biochemistry is language of biology. ✓ It is fundamental for study and understanding all biological process. ✓ The study of biochemistry is essential to understand basic functions of the body. ✓ Biochemistry: is the study of chemical process going on in the living organism at the molecular level. ✓ Besides, also deal with the nature of chemical constituents, functions and reaction happening in the living cells of all organisms 3 Biochemistry: Scope Knowledge of biochemistry is very important in many sectors such as: ✓ Microbiology, ✓ Cell biology, ✓ Physiology, ✓ Pathology, ✓ Immunology, ✓ Molecular biology, ✓ Genetics, ✓ Botany, ✓ Nutrition, ✓ and …etc 4  Biochemistry & Nutrition Biochemistry and Nutrition “Every Nutrition Process has a biochemical basis” 5 Why biochemistry is important in nutrition fields Biochemistry and Nutrition Biochemistry Nucleic acid Proteins Lipids Carbohydrates Genetics Growth/ Energy/ Energy information Repair Protection Digestion Diseases Build cell Regulation Weight Structure Diseases Blood sugar Nutrition 6 Why we study Nutritional Biochemistry? Nutritional Biochemistry ✓ To investigate the impact of nutrition on both physical and mental health of human. ✓ To understand the interactions between diet and disease. 7 Carbohydrates Carbohydrates Introduction: Carbohydrates are widely distributed both in animal and plants tissues as glucose/glycogen and starch, respectively. Definition: known as “hydrates of carbon” A polyhydroxy aldehydes (H-C=O-) or ketones (C-C=O-) contains a number of alcohol groups (‐OH) with the empirical formula Cm(H2O)n Functions: 1- Main source of energy in the body, e.g. Glucose 2- Cell membrane components e.g. Glycoprotein and glycolipids 3- Structure components of many organism e.g. Cellulose 4- Most important in DNA& RNA nucleotides e.g. Ribose sugar 9 Classification of Carbohydrates Carbohydrates are classified into 4 groups : I. Monosaccharides: (Greek, mono = one) Sugar cannot be further hydrolyzed into smaller unit II. Disaccharides: Two monosaccharides combined with elimination of water molecules (-H2O ) III. Oligosaccharides:(Greek, oligo = a few) from 3, 4, 5, …less than/or10 sugars IV. Polysaccharides:(Greek, poly = many) more than 10 sugars units are combined 10 Classification & structure of Carbohydrates I. Monosaccharides (Cn(H2O)n): (Simple sugar) Classified according to three different characteristics: 1- Number of carbon atoms 2- The placement of its carbonyl group, 3- Chiral carbon handedness ("left-handed" form (L form) and a "right-handed" form (D) form). All Monosaccharaides can be derived from glyceraldehyde (C3). 11 Monosaccharideds I. Monosaccharides: (Simple sugar) cont… 12 Monosaccharideds L &D Sugars: Note:- only D-sugars are metabolized by the human body and all naturally occurring sugars are D- sugars 13 Disaccharides(C12H22O11) Disaccharides(C12H22O11): (Two sugars linkages with O-glycosidic bond) that can be made from same or different monosaccharides. Type of glycosidic bonds: - α-glycosidic bond: linkage between a C-1α OH and a C-4 OH - β-glycosidic bond: linkage between a C-1 β OH and a C-4 OH 14 Disaccharides(C12H22O11) Disaccharides(C12H22O11): Maltose: D-Glucose + D-Glucose ✓ Obtained by acid or enzymes hydrolysis of starch ✓ Very soluble in water and has reducing properties ✓ It is widely used in infant feeding Lactose: (β-D-Galactose+ β-D-Glucose) ✓ Milk sugar (β-D-Galactose+ β-D-Glucose) ✓ It is no very soluble and is not so sweet ✓ It has reducing properties and can form osazones Sucrose: table sugar or Cane sugar (α-D-Glucose + -β-D-Fructose) ✓ Obtained from sugarcane or sugar beet ✓ Occurs free in most fruit and vegetables ✓ It is invert sugar ✓ Very soluble and sweet ✓ It does not exhibit reducing properties, why? 15  Oligosaccharides Oligosaccharides: ✓ Is a saccharide polymer containing a small number of ( typically 3 to about of 10 or 12) monosaccharides units, that Dextrin can be made from same sugar units (homopolysaccharides) or different (Heteropolysaccharides) Example: Dextrin, Raffinose, Stachyose ✓ Dextrin: is an intermediate product in the conversation of starch to maltose ✓ Raffinose: sugar found in in legumes, whole grains, cabbage, broccoli, cotton seed, …etc. ✓ Stachyose: use as sweetener, less than sucrose, occurs naturally in numerous vegetables: green beans, soybeans and other beans 16 Polysaccharides Polysaccharides: ✓ Are a complex of carbohydrates joined together by glycosidic bond ✓ Contains more than 10-12 monosaccharides units (up to 1000) can be linear or highly branched. ✓ Can be divided to: 1- Homopolysaccharides 2- Heteropolysaccharides) 17  Polysaccharides Polysaccharides: ✓ Homopolysaccharides 1- Starch: - composed from amylose and amylopectin - It is an insoluble in cold water Amylose: 15 – 20% Amylopectin: 80 – 85% straight chain of glucose (unbranched) High branched of glucose structure. soluble in water Insoluble in water, can absorb water and swell up. include 250 to 300 D- Glucose units linked (α1- 4 18  Polysaccharides Polysaccharides: ✓ Homopolysaccharides 2- Cellulose: it is a polymer of Glucose. Very stable insoluble compound. Have no nutritional value to human body. Most abundant polysaccharide. enhance and elimination of indigestible food residue. Most abundant polysaccharide. It consider as dietetic value (add bulk to intestinal contents). β (1 - 4) glycosidic linkages 3- Dextrin: Occurs when starch hydrolyzed with acids or enzymes. Widely used in infant feeding Contain 3-8 glucose units 4- Glycogen (animal starch): It is a polymer of D-Glucose Similar to amylopectin but highly branched Storage in liver and muscle in Humans and other vertebrates 19  Polysaccharides Polysaccharides: ✓ Heteropolysaccharides: Polysaccharides conjugated with another compound (attached by glycosidic bond to non-glycosidic bond) such as protein or lipids 1- Proteins (Glycoprotein) - Heparin - Blood group substances 2- Lipids (Glycolipids) 20 Physical & Chemical Properties of Monosaccharides Physical Properties of Monosaccharides Monosaccharides are: ✓ Colorless ✓ Sweet in test ✓ Quite soluble in water ✓ Crystalline solids at room temperature ✓ Stereo isomerism D-glucose and L-glucose are mirror images of each other. 22  Reducing Sugars Reducing Sugars ✓ If the oxygen in anomeric carbon(aldehyde or ketone functional groups) is free (not attached) that sugar is reducing sugar and define as: “A sugar acts as reducing agent and can effectively donate electrons to some other molecule by oxidizing, it is called reducing sugar” ✓ All monosaccharides are reducing sugars, because the oxygen in carbonyl group is free, either cyclic or open chain form. ✓ Disaccharides , lactose and maltose (except sucrose) are reducing sugar, because there is a free anomeric carbon in one of the glucose molecules. Free reducing end 23  Reducing Sugars Reducing Sugars ✓ Disaccharides sucrose) is not reducing sugar WHY? 24 Reduction of Monosaccharaides Reduction of carbonyl carbon( Aldehyde or keto group) produces a new Sugar alcohol. Such as Glucose reduced = form sorbitol, Mannose = form mannitol, Glyceraldehyde = form glycerol. 25 Oxidation of Monosaccharaides 26  Oxidation of Monosaccharaides Oxidation of Monosaccharaides Aldoses sugars my Oxidized to 3 types of acids: 1. Aldonic acids: aldehyde group converted to carboxy group (C-OOH) Ex: Glucose - Gluconic acid, Galactose - Galctonic acid, Mannose - Mannonic acid 2. Alduronic acids: the alcohol at the end, opposite to the aldehyde is oxidation to carboxy group. EX: Glucose - Glucuronic acid, Galactose - Galacturonic acid. Mannose - Mannuronic acid 3- Saccharic acid: oxidation at both end of monosaccharaides Ex: Glucose - Glucosaccharic acid, Mannose – Mannaric acid 27 Lipids ( Fats/Oils)  What is the Lipid? Introduction: Its organic compounds, nonpolar molecules, hydrophobic, which are insoluble in water and soluble only in nonpolar solvents, such as Ether, Chloroform and Benzene They are isolated from other biological molecules by extracting them with nonpolar solvents Fat and oil are the principle stored from in many organism They serve as a transporter form of metabolic process They provide structure component of membrane such as Phospholipids, Glycolipids, Sphingolipids Serve as pigment(carotene), hormones (vit D &A), cofactors ( Vit E & K), detergents (bile salt) and signaling molecules (steroid hormone). Protective function 29  Clinical significance of lipids Following disease are associated with abnormal chemistry of metabolism of lipids Obesity Atherosclerosis Diabetes Millets Hyperlipoproteinemia Fatty liver Lipid storage diseases (lipidoses) 30 Classification of Lipids: 31  Fatty acids(FA) Definition: A carboxylic acid that occurs with hydrocarbon chain ranging in length from 2 to 36 Type of Fatty acids: 1- Saturated FA A- Short chain Saturated F.A. (2-10 carbon). - Volatile and water-soluble F.A.(2-6 C). Acetic, Butyric, Caproic acid - Non-volatile and water-insoluble F.A.(7-10 C). Caprylic (8C), Capric (10C) B- Long chain Saturated F.A.(more the10 carbon) - Myristic (14C), Palmitic (16C), Stearic (18C) 2- Unsaturated FA: A- Monounsaturated FA:- Oleic acid (one double bond) 18C B- Poly unsaturated FA: 2 double bond = Lenoleic acid (18C) 3 double bond = Lenolenic acid (18C) 4 double bond = Arachidonic acid (20C 32  Formation of Triacylglycerol (TCA) (Fat and Oil) ester bonds O CH2 O C (CH2)14CH3 + H2O O in this example Glycerol +3 plasmatic acid CH O C (CH2)14CH3 + H 2O but most often triglyceride contain mixer O of fatty acids CH2 O C (CH2)14CH3 + H2O 33 Protein  What is the Proteins? Introduction: Proteins are biomolecules comprised of polymer of amino acid joined together by peptide bonds. “Biomolecules: are molecules produced by living organisms”. Are involved in most of the body’s functions and life processes 50% of dry weight of the most cells are proteins The type, number and sequence of amino acids are determined by DNA. Each type of protein has its own unique structure and function Proteins are organic nitrogenous compounds composed of C,H,O and N2 35 Biological importance of Proteins? 36  Amino acid structure Amino acids are the building blocks of proteins > 300 AA occurs naturally, 22 of them make up protein in animal & plants, and 20 out of them are directly specified by genetic code in DNA 37 Abbreviations are used to name an amino acids 38  Amino acid properties 1- Soluble in polar solvents Soluble in water and alcohol, WHY? 2- Colorless don't absorb visible light, except aromatic amino acid absorb UV-light at 280nm wavelength 3- Stereoisomerism AA have the same molecular formula and same structural group but differ in orientation of group in the space 39  Amino acid properties 3- Stereoisomerism: Ex. How about Glycine amino acid? What are the naturally occurring amino acids in mammalian? 40 Classification of Amino acids: Amino Acids 20= Standard amino acids Non-Standard amino acids 21- Selenocysteine (Sec) - D- amino acid 22- Pyrrolysine (Pyl) - Non-protein AA - AA derivatives 41 Classification of Amino acids: 42 Classification of Amino acids: Based on Metabolic Fate Ketogenic Both(Ketogenic &Glucogenic Remaining 14 amino acid - Phenylalanine eg. - Alanine -Leucine - Isoleucine -Lysine - Aspartate - Tryptophan - Tyrosine - Glycine - Methionine …etc. 43 Classification of Amino acids: Based on Nutritional Requirement Essential AA Semi-essential AA Non-essential AA - Tryptophan - Histidine - Glycine - Arginine Non-essential AA synthesized - Valine - Alanine from essential AA - Phenylalanine - Serine - Tyrosine (from Phe) - Cysteine (from Met) - Threonine - Cysteine - Isoleucine - Aspartate Non-essential AA get from food/synthesized in our selves - Methionine - Asparagine - Histidine - Glutamate - Arginine Conditional essential AA - Glutamine - Starvation - Leucine - Tyrosine - Inborn error metabolism - Lysine - Proline TVP TIME HALL 44  Amino acids and clinical correlation Amino disorder will lead to: Phenylketonuria (PKU) Tyrosinemia Albinism Alkaptonuria Homocystinuria Carcinoid syndrome Hartnup disease 45  Protein chemistry Formation of Peptide Bonds ✓ A peptide bond is formed by a dehydration reaction between two amino acids. ✓ Amino acids bond together in a specific sequence, number and types to form proteins. ✓ This reaction is also known as a condensation reaction which usually occurs between amino acids. 46 Peptide Bonds Formation of Peptide Bonds by Dehydration Condensation (dehydration)reaction between (α–carboxyl) group of an amino acid with (α-amino) group of another amino acid 47  Peptide Bonds Many amino acids joined together to form = poly peptides chains Amino acid residues of peptides are numbered from the N—terminal towards the C-terminal 48 The roles and fate of Macronutrients Biochemistry of the molecules and their processing in the living cells 50  Metabolism process Energy Containing Nutrients Energy Depleted Fats Catabolism and products CO2 CHO’S Proteins H2O NH3 ADP+HPO4 ATP NAD+ NADH NADP+ NADPH FAD FADH2 Cell Precursor Macromolecules Molecules Proteins Amino acid Lipids Anabolism Sugars polysaccharides Fatty acid Nucleic acid Nitrogenous bases  The roles and fate of macronutrients Carbs: Carbs are broken down into pyruvate in a process called glycolysis end by 2 pyruvates. Pyruvate‘s fate depends on the body’s needs, it is either: ✓ turned into energy and CO2 or ✓ converted into fats through acetyl-CoA or ✓ converted into amino acids through oxalacetate or ✓ turned into glucose again through oxalacetate in case of low body sugar. Fats: Dietary fats (triglycerydes) are broken down into acetyl-CoA, which can be either oxidized into energy and CO2 or used for synthetis of (other) fats. Proteins: (amino acids) Simplified amino acids can go two ways: ✓ either through pyruvate into acetyl-CoA (energy and fat synthesis) or ✓ some of the amino acids can be used for glucose synthesis through oxalacetate. 52 The roles and fate of macronutrients ATP Glycolysis O2 FADH2 ATP + NADH 53  Want big impact? USE BIG IMAGE Chairman’s Lorem ipsum dolor et vera Message adipiscing elit. Pellentesque Thank you, 4 invax hendrerit diam, et mollis libero. Curabitur sed facilisis elit. UR, Coming! Mauris semper vitae porta. 20/1/2025 In congue velit se Integer sales Felisex. 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