Week 2- Energy Metabolism Flashcards
Metabolism
All biochemical reactions in the body
Catabolism
The breakdown of complex molecules in living organisms to form simpler ones, together with the storage of energy; destructive metabolisms
pathway - breakdown molecules/ substrate
Anabolism
the synthesis of complex molecules in living organisms from simpler ones together with the storage of energy; constructive metabolism
pathway - build molecules
Energy Metabolism
The process of generating energy (ATP) from nutrients
Substrates
Compounds at the start of the pathway
Intermediates
Compounds formed throughout the pathway
Products
Compounds resulting from the pathway
Metabolic Pathway
Biochemical reactions that occur in progression from substrate to product, usually involving enzymes and co-factors
Aerobic metabolism of glucose
1.. Glycolysis (anaerobic step)Glucose is oxidized to pyruvate in 8 steps.
Requires vitamins B1, B2, B3, B6, B5 and magnesium
- Pyruvate is metabolised to acetyl coenzyme A (CoA) by pyruvate dehydrogenase. Requires vitamins B1, B2,B3, B5 and magnesium. (CoA is made from vitamin B5)
- Acetyl CoA enters citric acid cycle (CAC) producing NADH+ H+ , FADH2 and CO2 in 8 steps
- Electron transport chain: ATP is derived from NADH + H+ and FADH2 as H+ travel down the concentration gradient from the inter- membrane space via ATP synthase. Requires copper and iron
Anaerobic metabolism of glucose
- Occurs in cells with no mitochondria (RBC) or in any cells when there is no oxygen available
- Pyruvate is converted to lactate (rather than acetyl CoA in aerobic metabolism):
Pyruvate + NADH + H+ Lactate +NAD+ • NAD+ is then recycled to fuel glycolysis
Acetyl CoA
- The central molecule
- The entry into citric acid cycle
- The basis for making new fat
Gluconeogenesis
- forms ‘new’ glucose (from non-glucose sources) from glucogenic amino acids
- During short-term fasting periods, the liver produces and releases glucose mainly through glycogenolysis
- primary source of endogenous glucose production
Niacin (V3) and Riboflavin (V2)
- act as electron transporters, after absorption
- have to be activated into NAD (niacin) and FAD (riboflavin)
- help transfer hydrogens from energy-yielding compounds to oxygen in metabolic pathways.
Niacin
Functions as coenzyme: Nicotinamide adenine
dinucleotide (NAD):
- Oxidized form
- Reduced form (NADH) also found in cells
Riboflavin
Plays a similar role to Niacin:
Flavin adenine dinucleotide (FAD)
- Oxidized form – FADH2
- Reduced form
Esterification
Binding of fatty acids to glycerol
Beta oxidation
Oxidation of fatty acids to acetyl CoA
Glycogenolysis
Hydrolysis of glycogen to glucose
Gluconeogenesis
Production of glucose from the amino acids carbon skeleton
Glycogenesis
Production of glycogen from glucose
Glycolysis
Oxidation of glucose to pyruvate
Ketogenesis
Formation of ketone bodies
Lipolysis
Hydrolysis of triglycerides into fatty acids and glycerol
Protein Synthesis or Translation
Formation of gene products
Metabolism
the chemical processes that occur within a living organism in order to maintain life
Energy Metabolism
the process of generating energy (ATP) from nutrients
Anabolism
the synthesis of complex molecules in living organisms from simpler ones together with the storage of energy; constructive metabolism.
Catabolism
the breakdown of complex molecules in living organisms to form simpler ones, together with the release of energy; destructive metabolism.
Ketosis
a metabolic state characterized by raised levels of ketone bodies in the body tissues, which is typically pathological in conditions such as diabetes, or may be the consequence of a diet that is very low in carbohydrates.
Ketoacidosis
a serious complication of diabetes that occurs when your body produces high levels of ketones. The condition develops when your body can’t produce enough insulin
