C1: The importance of ATP Flashcards
What enzyme synthesises ATP
ATP synthetase
Define chemiosmosis
The flow of protons down an electrochemical gradient, through ATP synthetase accompanied with the phosphorylation of ADP to ATP.
Why is ATP referred to as the universal energy currency
It is used by all organisms, in every type of cell for all biological and metabolic processes
Three uses of ATP
Biosynthesis
Muscle contraction
Active transport
How is ATP suited to its role
6 points
Its Inert
It can pass through plasma membranes easily
it releases small, usable amounts of energy
Releases energy efficiently
it can be easily reformed by phosphorylation
It is easily hydrolysed to release energy
Other than mitochondria what other organelle can produce ATP
Chloroplast , on the thylakoid membrane.
Define an electrochemical gradient
Difference in concentration and charge on one side of a membrane.
How is an electrochemical gradient established in a chloroplast
In the LDS electrons are excited by light photons. These electrons move through a series of carriers in the thylakoid membrane and their energy is used to actively pump protons (from the photolysis of water) from the stroma into the thylakoid space, where they accumulate establishing an electrochemical gradient. chemiosmosis then occurs. Protons re-enter the stroma and combine with the electrons and NADP to form reduced NADP to be used in the Calvin cycle
How is an electrochemical gradient established in a mitchondria
In respiration electrons are excited by food.Their energy is made available through a series of carriers in the inner mitochondrial membrane. The energy pumps protons from the matrix across the membrane into the inter membrane space where protons accumulate and establish a electrochemical gradient. Chemiosmosis occurs and protons combine with electrons and oxygen to form water.
Name four similarities of ATP synthesis in mitochondria and chloroplasts
ATP synthetase
Protons provide energy for ATP synthesis
Excited electrons provide energy for H+ pumps
ETC is on the inner membrane of the organelle
Name seven differences of ATP synthesis in mitochondria and chloroplasts
Organelle formation: mitchondria / chlorolast
Type of phosphylation: Oxidative / photo
Energy source: from food in redox / Light
No. of proton pumps: 3 NAD, 2 FAD / 1
…………………….Site of ETC : Cristae / Thylakoid
……………Coenzymes: NAD and FAD / NADP
H+ gradient: I-MS to matrix / Thylakoid space to stroma
Final Electron acceptor : Oxygen / cyclic chlorophyll a, non cyclic NADP
Define photophosphorylation
A reaction bonding a phosphate ion to a molecule of ADP using energy from electrons excited by light making ATP
