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Energy Generation and Metabolism - Coggle Diagram
Energy Generation and Metabolism
Introduction on metabolism
Basic Metabolic pathways
Metabolic pathways are
The final product of a pathway forms a substrate for another pathway
Its a continuous process
Sequences of cellular reactions
Reactions are catalysed by enzymes
Each reaction provides the substrate for the next reaction
Anabolism
The build up (synthesis) of simple molecules to complex molecules
e.g glycogen from glucose
Generally require energy in the form of ATP
The names usually end in 'genesis'
e.g glycogenesis, lipogenesis, gluconeogenesis
Catabolism
The breakdown of complex molecules to simple molecules
e.g carbohydrates and lipids
Generally release energy in the form of ATP
The names usually end in 'lysis'
e.g proteolysis, lipolysis, glycogenolysis
Why do we need fuel
Activity can be intense of passive
Immediate use
ATP
Stored for later
Complex storage molecules
Control of metabolic pathways
Why do we need to control metabolic pathways
To meet energy requirements independently
Fuels are used efficiently and economically
To respond to different situations
Metabolic pathway rates are controlled dependent on what is happening at the level of the whole body, the organ and cell
One mechanism of control = localisation
Same subcellular compartment
catabolic enzymes in mitochondria
Same membrane
Electron transport chain
Same complex
Held with non-covalent bonds in multi-enzyme complex
Glucose metabolism
Sole source of fuel for the brain and central nervous system
Blood glucose levels need to be between 4.0-7.8 mmol/L
Hypoglycaemia
2.5 mmol/L - loss of consciousness
Glucose released from stores
Hyperglycaemia
12mmol/L - Polyuria, polydipsia, polyphagia
Glucose taken up by stores
Hormones: mechanisms of action
Paracrine
Hormone secreted from one cell. Binds to receptor on NEARBY cell
Endocrine
Autocrine
Hormone secreted from one cell. Binds to receptor on SAME cell