Jotting
Nutrient Metabolism
Nutrient are divided into two parts.
Macro-nutrient Micro-nutrient
1. Carbohydrate 1. Vitamins
2. Protein 2. Minerals
3. Lipid
Microbial Biochemistry [STH 301] FIRST LECTURE
Glucose
1. Glycolysis: is a process of converting glucose to pyruvate.
2. Gluconeogenesis: is a process of converting pyruvate to glucose.
3. Glucose to glycogen is a process called Glucogensis.
4. Glycogen to glucose can be called Glycogenolysis.
Nutrients are chemical substances which nourishes the body system and they are classified into two groups namely;
1. Macro nutrient
2. Micro nutrient
Macro nutrients consist it carbohydrates, protein and lipids while micro nutrients consists of vitamins and minerals.
Macro nutrients are usually taken in large quantities while the micronutrients are usually taken in small quantities.
Metabolism
Metabolism is a broad term which consist of anabolism and catabolusm.
Anabolism and Catabolism
Anabolism is the synthesis of chemical substances while Catabolism is the breakdown of organic substances to realease energy.
Carbohydrate metabolism
Fig 1.0 Image of carbohydrate metabolism.
Glycolysis/Glucose lysis
This is the conversion of glucose to pyruvate. It is one of the major pathways in the body.
Gluconeogenesis
This is the synthesis of glucose from non-carbohydrate sources e.g amino-acid, pyruvate and many others.
Glycogenesis
This is the synthesis of glycogen from glucose and this happens when the serum level of glucose is high and excess glucose is converted to glycogen for stage.
Glycogeneolysis
This is the process of breaking down of glycogen to glucose. This usually occurs when the level of glucose in the blood is low.
Pentose phosphate pathway
It is the conversion of glucose (hexose 6-carbon) to pentose sugar (a 5-carbon sugar) and other sugars.
GLYCOLYSIS
Glycolysis occurs in the cytoplasm of Eukaryotic cells and contains in the mitochrondia.
Glycolysis occurs at least in almost every livinh cells and these series of reaction is be ____ to be among the eldest of all the biochemical pathways. Both the enzymes and the number and mechanism of the step in the pathways are highly conserved in prokaryotes and Eukaryotes.
Glycolysis is also known as Embden-Mergerhef-Parnes Pathway.
Glycolysis pathways
fig 1.1 image of glycolysis pathway
Glycolysis involves 10 series of reactions as follows:
1. Synthesis of Glucose-6-phosphate: immediately after entering a cell, glucose are phosphorelated to give glucose-6-phoaphate in the presence of the enzyme hexokinase. This process is known irreversible.
2. Conversion of glucose-6-phosphate to fructose-6-phosphate: Glucose-6-phosphate is converted to fructose-6-phosphate in the presence of the enzyme phosphogluco isomerase in a readily reversible reaction.
3. Phosphorelation of fructise-6-phosphate: phosphorelation of fructose-6-phosphate is catalyzed by phosphofructokinase1 to give fructose-1,6-diphosphate.
4. Cleavage of fructose-1,6-diphosphate: stage 1 of glycolysis ends woth cleavage of fructose-1,6-diphosphate into two 3-carbon molecules i.e. Glyceraldehyde-3-phosphate and Dihydroxylacetone phosphate (G-3-P and DHAP) the reaction is catalysed by Aldolase.
5. Interconversion of Glycealdehyde-3-phosphate and Dihydroxylacetone-3-phosphate: the two products of aldolase reaction i.e. G-3-P and DHAP are being catalyzed by Trioxophosphate isomerase.
6. Oxidation of G-3-P: G-3-P undergoes oxidation and phosphorelation and the product is Glycerate-1,3-biphosphate in the presence of the enzyme Glycealdehyde-3-phosphate dehydrogenase. In this reaction ATP is synthesized.
7. Phosphoryl Group Transfer: in this reaction, ATP is synthesized as phosphoglycerate kinase catalysed the transfer of high energy phosphoryl group of Glycerate-1,3-biphosphate to ADP.
8. Interconvertion of 3-phosphoglycerate and 2-phosphoglycerate: this reaction which interconvert 3-phosphoglycerate and 2-phosphoglycerate is catalysed by Triose phosphate isomerase.
9. Dehydration of 2-phosphoglycerate: the enzyme endolase catalyzed the reversible reaction of 22-phosphoglycerate to phosphoenol pyruvate.
10. Synthesis of Pyruvate: pyruvate kinase catalysed the transfer of phosphonyl group from phosphoenol pyruvate to ADP are formed from each molecule of glucose.