cellular respiration overview Flashcards
what kind of work is done
mechanical, chemical, transport
what is energy coupling
using an exergonic/catabolic reaction to drive an anabolic/endergonic one.
How are enzymes catalyzing
- enzymes catalyze high energy organic molecules to simpler products
- some released energy is lost as heat, 40% of it is converted to ATP while 60% is lost as heat which can be used to maintain our body temperature
Why is ATP hydrolysis yield high energy
Because the phosphate bonds of ATP are high-energy bonds, they are unstable, and their hydrolysis yields energy because the products are more stable, all phosphate groups have a negative charge
- The release of energy during the hydrolysis of ATP actually comes from the change to a state of lower energy, not from the phosphate bonds themselves.
phosphorylated meaning
receiving a phosphate, becoming more reactive than the original unphosphorylated molecule
- these molecules undergo changes to endure work, such as through muscle action with myosin and actin:
- ATP binds with myosin, making it detach from actin
- ATP turns into ADP, releasing energy as myosin heads cock
- Ca+ binds to troponin, exposing sites on actin that myosin can grab
- myosin undergoes a power stroke to push on the actin
the three types of phosphorylation?
substrate level:
- occurs in the cytoplasm of cells during glycolysis and in mitochondria
- lower yield of glucose
- phosphorylated intermediate forms ATP from ADP
oxidative:
- process where energy is harnessed through a series of protein complexes embedded in the inner-membrane of mitochondria (called the electron transport chain and ATP synthase) to create ATP.
photo-phosphorylation:
- where light energy is used to generate a proton gradient and uses the energy from this gradient to drive the synthesis of ATP from ADP and inorganic phosphate.
where does the energy to phosphorylate ADP come from
catabolic cellular reactions
