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Metabolism Chapter 25
Metabolism
Chapter 25
Essential Nutrients
45 – 50 molecules must be ingested.
This includes representatives from the 4 major organic molecule groups, plus a number of inorganic substances such as including water, vitamins and minerals (Na, Fe, etc.)
The USDA Food Pyramid
Nutrient –A substance in food used by the body for growth,
maintenance, energy and repair.
• Carbohydrates: 55 – 60 % of daily calories. 125 – 175 g.
• Lipid: < 30% of daily calories. 80 – 100 g.• Protein: 0.8g/kg body weight.• Nucleic acids: not established• Water: 1500 ml (average) per day.
Uses of nutrients• Carbohydrate: Primary energy molecule. Also found on
cell membranes and as part of structure of connective tissue matrix molecules
• Lipid: Energy storage, plasma membrane structure, cushioning, steroid hormones.
• Proteins: Enzymes, receptors, hormones, structures of all kinds. Must be “complete” or “complimentary” in order to supply essential amino acids.
Essential amino acids
Energy Metabolism
• Metabolism = catabolism + anabolism• Cellular respiration is a series of catabolic
reactions that provide energy for the production of
• This energy is used to generate ATP from phosphorylation of ADP.
• It is a series of Redox reactions.
ATP
Summary of steps of energy
metabolism
Generation of ATP by “substrate-level phosphorylation”
Oxidative phosphorylation
Overview of cellular respiration
Carbohydrate Metabolism
C6H12O6 + 6 O2 6 CO2 + 6 H2O + 36 ATP + Heat
Oxidation of Glucose
Glycolysis: an Anaerobic process.It is the first stage in cellular respiration
Krebs cycle
The Electron Transport Chain
The ETC energy gradient
Summary of ATP synthesisGains & losses
Glycogenesis/Glycogenolysis
Summary of lipid
metabolism:oxidation
Metabolism of Triglycerides
Protein metabolism in the Liver
Carbohydrate/fat & amino acid pools
Interconversion of carbohydrate, lipid and protein
Pathways of the Absorptive state
The effects of insulin on
metabolism
Major Events of the Postabsorptive state
Influences of
Glucagon on blood glucose levels
Pathways of the Postabsorptive state
Composition of
Lipoproteins
Hypothetical feeding control mechanism
Heat Balance
Temperature regulation mechanisms
Maynard or Hans?
