3.1 importance of ATP Flashcards
what is adenosine triphosphate (ATP) made from?
- ribose
- adenine
- 3 phosphates
ATP is the universal energy carrier
(used in all reactions in all organisms)
how does ATP release energy?
what enzyme is the reaction catalysed by?
- via a 1 step reaction when the high energy bond between the second and third phosphate group is broken
- this hydrolysis reaction is hydrolysed by the enzyme ATPase
what are some examples of the processes that ATP provides energy for?
- protein synthesis
- muscle contraction
- DNA synthesis
- active transport
- mitosis
chemiosmosis definition
the flow of protons down an electrochemical gradient through ATP synthetase, coupled with the synthesis of ATP from ADP and a phosphate ion
during photosynthesis and respiration, when is ATP made?
- when protons are pumped across the membranes using energy from electrons to create an electrochemical or proton gradient
when does ATP synthetase phosphorylate ADP into ATP?
- when the protons flow back through the stalked particles down the concentration gradient, by a process known as chemiosmosis, ATP synthetase phosphorylates ADP into ATP
(in chloroplasts, this occurs on the thylakoid membranes, whereas in mitochondria, occurs on inner membrane or cristae)
the electrons pass from the proton pumps to a terminal electron acceptor?
what is this in mitochondria? in chloroplasts?
mitochondria : oxygen
chloroplasts : coenzyme NADP or chlorophyll
compare the mechanisms of ATP synthesis in mitochondria and chloroplasts
mitochondria:
- uses energy carried by electrons to pump protons across the membrane, they then flow back through stalked particles
chloroplast:
- uses electron energy to pump protons across the membrane which then flow back through stalked particles
compare the enzyme involved in ATP synthesis in mitochondria and chloroplasts
both ATP synthetase
compare the proton gradient of ATP synthesis in mitochondria and chloroplasts
mitochondria:
- from inter-membrane space to matrix
chloroplast:
- from thylakoid space to stroma
activation energy definition
the minimum amount of energy needed to start a chemical reaction
what is phosphorylation?
the addition of a phosphate group or ion to a molecules
in respiration and photosynthesis, what molecule is most often phosphorylated?
ATP
but other molecules can be phosphorylated as well
what are the 3 types of phosphorylation?
- oxidative phosphorylation
- photophosphorylation
- substrate level phosphorylation