Carbohydrates PDF

CARBOHYDRATES CARBOHYDRATES polysaccharide there will be General description: formation of water compounds containing Carbon Primary importance of (C), Hydrogen (H), and Oxygen...

CARBOHYDRATES CARBOHYDRATES polysaccharide there will be General description: formation of water compounds containing Carbon Primary importance of (C), Hydrogen (H), and Oxygen disaccharides is the nutrients (O) that they provide serves as General formula: Cn(H2O)n; biochemical markers for certain where n stands for the number disorders of carbohydrate of carbon present metabolism Carbohydrates are descriptively Simple sugars such as Glucose, defined as aldehyde and ketone Fructose, Galactose (Hexoses) compounds with polyhydroxyl Disaccharides are composed of 2 groups monosaccharides. The strutting structural feature Sucrose=Glucose + Fructose of carbohydrates is the (acid hydrolysis) presence of having large Lactose= Glucose + Galactose number of functional groups; Maltose= Glucose + Glucose both for hydroxyl and carbonyl Polysaccharides are made up of group many monosaccharides such as Provides energy to the body cellulose, glycogen, starch and chitin furnishing part of the structural integrity of the cell membrane GLUCOSE determining blood type and Glucose (Grape sugar/ others Dextrose) is the only Classified as Monosaccharides, carbohydrate to be directly Disaccharides, and used for energy or stored as Polysaccharides glycogen. Two classes of carbohydrates: Most abundant and most Simple and Compound important monosaccharide for Simple carbohydrates are human nutritional standpoint, it monosaccharides because they only is utilized to assess total have single sugar; while carbohydrate use of the body compound/complex sugars have two through fasting blood sugar units of sugar (disaccharides), analysis oligosaccharides has 3-10 FRUCTOSE monosaccharide units, and Also known as Nevulose or polysaccharides consists 10 Fruit sugar. monosaccharide units Formed from glucose and Monosaccharide breakdown of sucrose, and is water-soluble in white considered as the sweetest crystalline solid tasting sugar Every time that a Considered as intermediate in monosaccharide is linked the utilization of together to form di,oligo-, or monosaccharides  CARBOHYDRATES GALACTOSE is the branched form that Synthesized in mammary gland accounts for about 80% for the production of milk Primary carbohydrate in the diet sugar and is found in most plants Is a component of GLYCOGEN glycoprotein that is found in A polysaccharide that is similar the brain and nerve tissues; in structure with amylopectin hence called as brain sugars Liver cells and muscle cells are A chemical marker for antigen the storage sites of glycogen in that distinguishes various types human of blood types CELLULOSE SUCROSE Structural component of plant Also known as Common Table cell wall having similar structure Sugar; best known with amylose disaccharide Polysaccharide in plants not Is obtained from beets or sugar digested by humans that canes; sucrose is the most provides proper intestinal common non-reducing sugar functioning due to high which do not contain an active concentration of plant fibers ketone or aldehyde group Summary Sucrose upon hydrolysis will liberate glucose and one fructose LACTOSE Also known as milk sugar that GLUCOSE METABOLISM is usually found in dairy Regulation of blood glucose products level MALTOSE Level of glucose in the blood is Also known as malt sugars that a result of variety of metabolic are found in cereals, wheat, process. and malt products Maltose upon hydrolysis will 1. Glycolysis- Conversion of then produce two molecules of Glucose into Lactate or glucose pyruvate STARCH Glucose -> A homopolysaccharide Pyruvate/Lactate + containing only glucose Energy (ATP) monosaccharide unit that 2. Glycogenesis – conversion of normally exists in two; whether excess glucose into glycogen in amylose or amylopectin the liver for storage. In Amylose is an unbranched response to increasing blood glucose that accounts for 20% glucose level. of the starch; while Amylopectin  CARBOHYDRATES 3. Glycogenolysis – breaking GLUCAGON down of stored glycogen to Is the primary hormone glucose for use as energy. In responsible for increasing response to decreasing blood glucose (hyperglycemic or glucose level. diabetogenic agent) 4. Gluconeogenesis – conversion It is synthesized by the α-cells of non-carbohydrate substance of the islets of Langerhans in such as amino acids, fatty the pancreas acids, glycerol and lactate to It enhances catabolic functions glucose when glycogen stores during fasting period; promotes are used up in 48 hours glycogenolysis and (starvation) gluconeogenesis. 5. Lipogenesis – conversion of It is released during stress and carbohydrates to fatty acids. fasting states OTHER HORMONES THAT TEND TO REGULATION OF BLOOD INCREASE GLUCOSE GLUCOSE CONCENTRATION Insulin Epinephrine A 51 amino acid protein, The Cathecolamines like primary hormone responsible norepinephrine, adrenalin, and for the entry of glucose into the noradrenaline are released from cell the chromaffin cells of the Synthesized by precursors adrenal medulla during known as proinsulin (a single emergency situations and polypeptide containing α, β, and stress c peptide chain) Inhibits insulin secretion and C peptide chain is removed by increases glycogenolysis and peptidases (enzyme used to lypolysis convert proinsulin to become an Cortisol active insulin; synthesized by Secreted by the cells of the β-cells of the islets of zona fasciculata and zona Langerhans in the pancreas reticularis of the adrenal cortex It is normally released when which decreases intestinal entry glucose levels are high of glucose into the cell It promotes glycogenesis, It promotes gluconeogenesis, lypogenesis, and glycolysis, glycogenolysis and lipolysis while decreasing glycogenolysis Cushing syndrome: Increased cortisol, It is the only hormone that increase in hyperglycemia decreases glucose levels Addisons disease: Decreased cortisol, (hypoglycemic agent) decrease in hypoglycemia Stored from sources such as Growth Hormone liver, fat and muscle Also known as Somatotropin Has a reciprocal relationship Secreted by the anterior with glucagon pituitary (Adenohypophysis)  CARBOHYDRATES gland which reduces entry of trouble talking, confusion, loss glucose into the cell by of consciousness and even increasing glucose seizure or death. concentration in the blood due Results from an imbalance to reduced transport to the cell between glucose utilization and for utilization production. It promotes glycogenolysis A diagnosis of hypoglycemia (glycogen breakdown) and should not be made unless a glycolysis (glucose catabolism) patient meets the criteria of Adrenocorticotrophic Hormone Whipple’s Triad. (ACTH) 1. Symptoms known or likely to be It stimulates release of cortisol caused Hypoglycemia specially after from the adrenal cortex fasting or heavy exercise. Participates in the conversion of 2. A low plasma glucose measured at liver glycogen to become the time of the symptoms 126mg/dL (around History of impaired 7mmol/L) or more than one glucose/impaired glucose testing. tolerance Complications of diabetes mellitus Ketosis It develops in Diabetes Mellitus The complication of DM Excessive synthesis of Acetyl problems that develop rapidly CoA – obtaining energy from (acute) or over time. stored fat Chronic complications it will in the absence of adequate now affect many organ supply of carbohydrate systems. metabolites. The complication of DM can The presence of ketone bodies dramatically impair the quality of is a frequent finding in life. So it can have long lasting individuals with severe disability. uncontrolled diabetes. Over all the complications are Ratio of β-hydroxybutyric acid to far less common and less acetoacetate 2:1 severe if people with control Can be reversed by bicarbonate blood sugar levels. But there infusion. are some non modifiable risk Criteria for diagnosis of diabetes factors (E.g. Genetics, Age, mellitus Gender) Obesity Modifiable are example of Family history of diabetes in first lifestyle, smoking, obesity, High degree relative blood pressure or elevated Membership in a high risk cholesterol level, lack of regular minority population (African, exercise and that can lead to American, Hispanic Americans, DM. Native American, Asian Classifications of diabetes mellitus American) Type 1 Diabetes Mellitus History of GDM or delivering Due to genetics babies >9 lbs It results from the pancreas Hypertension (>140/90) failure to produce enough Low HDL (500mg/dL and it can have No known etiology, strongly severe dehydration, electrolyte inherited, does not have β-cell imbalance, increase of BUN autoantibodies and requires and crea episodic insulin replacement Other types of Diabetes Mellitus This type of diabetes is strongly Associated with secondary inherited. It does not have beta conditions cell autoantibodies and it has Genetic defects of beta-cell episode requirements for insulin function replacement. Pancreatic diseases Type 2 Diabetes Mellitus Drug or chemical induced It actually begins in insulin Insulin receptor abnormalities resistance ( it is a condition in Other genetic syndromes which the cells fail to respond to Pancreatic disorders (Ex. Type insulin properly ) 1 DM) As the disease will progress a Endocrine disorders (E.g. lack of insulin will develop. Hormones and it can result to Risk factors: Most common Cushing’s syndrome, Klinefelter cause of type 2 DM is syndrome, RabsonMendenhall syndrome (extremely rare  CARBOHYDRATES genetic disorder characterized GDM is diagnosed if 2 plasma by severe insulin resistance), values or more of the above Leprechaunism (extremely rare glucose levels are exceeded disorder characterized by According to the studies GDM abnormal resistance to insulin) converts to DM within 10 years ). in 30 to 40 cases. Impaired insulin action The mother with GDM should Genetic syndromes be evaluated 6 to 12 weeks Gestational Diabetes Mellitus (GDM) after giving birth. GDM only occur during Impaired Fasting Glucose pregnancy and it will disappear It is characterized by fasting after delivery but there are blood glucose concentrations some cases that it return years between normal and diabetic later. degree of glucose values. intolerance with onset or first Impaired Glucose Tolerance recognition during pregnancy. It is characterized by fasting Disorder characterized by blood glucose concentrations impaired ability to metabolize less than those required for the carbohydrate and it caused diagnosis of diabetes, but the deficiency in insulin or Due to OGTT is between normal and metabolic and hormonal diabetic values. changes during pregnancy OTHER METHODS FOR Risk factor: Over weigh , have QUANTIFICATION OF BLOOD history of gestation of diabetes GLUCOSE and possible to have again, RBS (Random Blood Sugar) family history of Type 2 DM and Requested if he patient have PCOS insulin shock or Hyperglycemia GDM diagnosed by Blood test coma (E.g. Screening that is FBS (Fasting Blood Sugar) recommended between 24 - 28 Should be not dating and weeks gestation ) drinking anything at least 8- to Glucose challenge test (50 10 hours fast before the test grams of glucose) (not longer than 16 hours). A plasma glucose concentration 2-Hour PPBS (2-Hour Post-Prandial of 140mg/dL or greater requires Blood Sugar) a full diagnostic glucose A solution containing 75 g of tolerance test (3-hour GTT with glucose is administered, and a 100g glucose). specimen for plasma glucose OGTT Results: FBS - ≥95 measurement is drawn 2 hours mg/dL later. Under this criterion, the 1-hour - ≥180 mg/dL 2-hour - patient drinks a standardized ≥155 mg/dL 3-hour - (75 g) glucose load and a ≥140mg/dL glucose measurement is taken 2 hours later. If that level is  CARBOHYDRATES >200mg/dL and is confirmed on endocrine dysfunctions a subsequent day by either an increased random or fasting Intravenous Glucose-Tolerance Test glucose level, the patient is (IVGTT) diagnosed with diabetes It is used for diabetes patients OGTT (Oral Glucose Tolerance Test) with gastrointestinal disorders Janey-Isaacson Method (Single 0.5 g of glucose/kg body weight Dose Method) (given w/in 3minutes) Exton Rose Method (Divided administered intravenously. Oral Dose/Double Dose) Fasting sample is also required. Multiple blood sugar test and it (10 hrs) will help to determine how well The first blood collection is after the body metabolizes glucose 5 minutes of IV glucose. over the time given period Indications (IVGTT) Requirements for OGTT: Those who are unable to A. Patient should be ambulatory tolerate a large carbohydrate CHO depletion and load. inactivity or bed rest Those with altered gastric impair glucose tolerance. physiology. B. Fasting of 8-14 hours. (not Those who had undergone longer than 16 hours). previous operation or surgery in C. Unrestricted diet of 150g the intestine. carbohydrate/day for 3 days Those with chronic prior to testing. to stabilize the malabsorption syndrome. synthesis of inducible glycolytic enzymes. KINDS OF GLUCOSE TOLERANCE D. The patient should not smoke TEST and drink alcohol prior to Oral Glucose Tolerance Test testing. e. Glucose load A. Janey-Isaacson Method 75gms (WHO standard glucose (single Dose Method) – most load) common. 100gms B. Exton Rose Method (Divided 1.75g of glucose/kg body weight Oral Dose or Double dose (children and maximum of 75). method) Factors that affect the tolerance Added plasma Glucose after OGTT: results: 30 mins = 30-60mg/dL above Salicylates fasting Diuretics 1 hour = 20-50mg/dL above Anticonvulsants fasting oral contraceptives 2 hour = 5-15mg/dL above corticosteroids. fasting malabsorption problems 3 hour = fasting level or below gastrointestinal surgery Procedure for OGTT Vomiting  CARBOHYDRATES The patient should avoid MONITORING TEST FOR DIABETES exercise, eating, drinking MELLITUS (except water) and smoking Glycosylated Hemoglobin (HbA1C) during the test. Also called glycated hemoglobin For non pregnant women and It is the largest subfraction of adults, only the fasting and the normal hemoglobin in both 2 hour sample may be diabetic and non-diabetic measured (or according to the individuals. physician’s request). It is a glucose molecule 1. Collect the fasting blood sample attached to one or both (urine may also be collected) Nterminus valines of the beta 2. Instruct the patient to drink the polypeptide chains of normal glucose load. adult hemoglobin. 3. Collect blood sample after 30 A reliable method in the minutes, 1 hour, 2 hour, 3 hour, monitoring of long-term respectively. (4 samples in a diabetes control. day) It reflects the average blood Criteria for Fasting Plasma Glucose glucose level over the previous 2-3 months. For every 1% change in the HbA₁c value, 28.7 - 35mg/dL is added to plasma glucose. Not suitable for patients with shortened RBC lifespan disorders – low HbA₁c value. 3%-6% HbA₁c = normal glycosilation; 18%-20% HbA₁c is prolonged hyperglycemia. 7% HbA₁c = cut off value set by Criteria of Glucose Tolerance Test American Diabetes Association (ADA). Specimen: EDTA and the sample is WHOLE BLOOD It is done by twice a year or have a treatment goal if not it can have quarterly. Methods: electrophoresis, Chromatography immunoassay, HPLC, Affinity  CARBOHYDRATES Inborn Errors of Carbohydrate Metabolism Galactosemia Essential Fructosuria Hereditary Fructose Intolerance Fructose 1,6-biphosphate deficiency GALACTOSEMIA Deficiency of enzyme galactokinase, galactose 1-phosphate uridyl transferase, Risk for DM (TEST) or uridyl diphosphate glucose FBS 4-epimerase. 2 hour OGTT Most commonly galactose HbA1c- 1-phosphate uridyl transferase Diagnostic of DM is deficiency which leads to RBS excessive galactose in blood FBS and excretion in urine. 2 hour OGTT Infants with galactosemia HbA1c usually have diarrhea and Routine Test for Monitoring DM vomiting within a few days of FBS drinking milk or formula HbA1c containing lactose Microalbuminuria PART OF NEWBORN SCRENING RA9288 FRUCTOSAMINE Congenital Hypothyroidism Also called glycosylated (CH) albumin or glycated albumin Congenital Adrenal Hyperplasia plasma protein ketoamine. ( CAH) t is a reflection of short-term Galactosemia (GAL) glucose control (2-3 weeks). Phenylketonuria(PKU) May be useful for monitoring Glucose-6-phosphate-dehydrog diabetic individuals with chronic enase deficiency (G6PD def.) haemolytic anemias and Maple Syrup Urine isease hemoglobin variants (Hb S Hb (MSUD) C) – decreased RBC lifespan. Must to know! It should not be measured in Serum must be separated from cases of low plasma albumin the cells within 30 mins (