Lecture 12: Intro to Metabolism Flashcards
Energy vs Matter
energy FLOWS through living systems via chemical reactions
matter CYCLES through living systems via chemical reactions
potential energy
can be transformed to kinetic energy or a different type of potential energy
why does ice cream, a tree and gasoline all represent chemical energy?
their energy is used to do mechanical work (energy in bonds are broken)
what evidence is there of potential energy of covalent chemical bonds?
- hydrolysis of ATP powers motor proteins
- light and heat are released when cellulose is burned
- triglycerides store about twice as much energy as polysaccharides
- in energy-coupling pathways, catabolism powers anabolism
coupling potential energy to kinetic energy
the potential energy of covalent bonds and electrochemical gradients provide energy for all cellular work
where does the energy to phosphorylate ADP to come from?
breaking of covalent bonds in lipids and carbohydrates
What’re the molecular products of cellular respiration?
CO2 and H2O
coupling of oxidation events
produces the energy to phosphorylate ATP and allow for transport work, mechanical work, and chemical work
Energy in respiration
energy is transformed from covalent bonds in glucose to the covalent bonds of ATP
matter in respiration
glucose is oxidized to CO2. Oxygen is reduced to water
Oxidation
lose hydrogen, lose electrons
reductions
gain hydrogen, gain electrons
NAD+
accepts two electrons and one H atom to reduce to NADH
FAD
accepts two electrons and two protons to become FADH2
(In diagram) AH -> A, B ->BH
AH= glucose A= CO2 B= O2 BH= H2O
