BIOL1008 Lecture 8: Lecture 8
Lecture 8: Break it down and build it up
Metabolism
- Total of all chemical reactions that occur in the body
- Two types of metabolic processes:
Catabolism
• Energy-releasing process
• Large molecules → smaller ones (degradation)
• Begins with digestion, then occurs within cells
• Energy used to drive anabolic reactions
Anabolism
• Energy-requiring process
• Small molecules joined → larger ones (biosynthesis)
• Within all cells
• Formation of new cells, maintenance of existing cells,
production of molecules (e.g. hormones, enzymes)
Mnemonic: Anabolism = Biosynthesis, Catabolism= Degradation
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2
Activated carrier molecules
- Link anabolism and catabolism
- Reversibly carry chemical bond energy in easily exchangeable forms
As a transferable chemical group or as high energy electrons
The most abundant activated carrier molecule:
- ATP
Energy currency of the cell
Conversion to ADP releases energy • Lik aaolis ad ataolis • Reversibly carry chemical
od eerg i easil ehageale fors • As a trasferale heial group or as high energy
electrons
ATP facts:
- Generated from metabolic fuel e.g.
catabolism of carbohydrates, lipids
- Body maintains steady supply of ATP
For anabolic reactions: growth,
reproduction, exercise, immunity, etc
For essential cell housekeeping e.g.
maintaining ion gradients
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3
Cell [ATP] is generally about 5 mM; Cellular [ATP] < 3 mM
→
cell death
- We at store ATP, so it is made on demand
We a ol store it idiretl as fuels like lipids and carbohydrate
- TURNOVER is massive in comparison to store size
Total amount of ATP in whole body ~250 g
Total production and destruction of ATP is almost 1 kg/kg body weight/day
- Rate of ATP generation = rate of ATP consumption
Carbohydrate metabolism
- Carbohydrates digested to
monosaccharides
Glucose is the most
important
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Document Summary
Lecture 8: break it down and build it up. Total of all chemical reactions that occur in the body. Catabolism: energy-releasing process, large molecules smaller ones (degradation, begins with digestion, then occurs within cells, energy used to drive anabolic reactions. Anabolism: energy-requiring process, small molecules joined larger ones (biosynthesis, within all cells, formation of new cells, maintenance of existing cells, production of molecules (e. g. hormones, enzymes) Reversibly carry chemical bond energy in easily exchangeable forms. As a transferable chemical group or as high energy electrons. Conversion to adp releases energy li(cid:374)k a(cid:374)a(cid:271)olis(cid:373) a(cid:374)d (cid:272)ata(cid:271)olis(cid:373) reversibly carry chemical (cid:271)o(cid:374)d e(cid:374)erg(cid:455) i(cid:374) easil(cid:455) e(cid:454)(cid:272)ha(cid:374)gea(cid:271)le for(cid:373)s as a tra(cid:374)sfera(cid:271)le (cid:272)he(cid:373)i(cid:272)al group or as high energy electrons. Generated from metabolic fuel e. g. body maintains steady supply of atp catabolism of carbohydrates, lipids reproduction, exercise, immunity, etc maintaining ion gradients. For essential cell housekeeping e. g. cell [atp] is generally about 5 mm; cellular [atp] < 3 mm cell death.