ATP Flashcards
What does ATP stand for?
Adenosine triphosphate
What is ATP?
A nucleotide found in all living organisms
What are the 3 components of ATP?
3 phosphate groups
Ribose sugar
Nitrogenous base adenine
Where is chemical energy stored?
Lipids
Carbohydrates like glucose
How does respiration oxide glucose?
Series of small reactions to release energy in the form of ATP
Is ATP an energy store?
No
Is an energy currency
Synthesised as it is required
What is ATP involved in?
Energy changes
Carrying the energy to where it is needed and releasing the energy when ATP is broken down
Why is ATP called the ‘universal energy currency’?
It provides energy for many metabolic reactions in all living organisms
What are the uses of ATP?
Active transport
Muscle contraction
Nerve impulse transmission
Secretion (packaging molecules into vesicles for exocytosis)
Synthesis of complex molecules from smaller simpler molecules e.g. proteins/nucleic acids
How is ATP formed?
Enzyme ATP synthase combines ADP & Pi (inorganic phosphate) in a condensation reaction
Requires an input of energy (30.6kJmol-1) in an endergonic reaction
Addition of this phosphate to ADP is called phosphorylation
What is the hydrolysis of ATP?
Enzyme ATPase hydrolyses the terminal phosphate bond releasing a small packet of energy (30.6kJmol-1) in an exergonic reaction
Forms ADP and Pi
What is the equation for the hydrolysis of ATP?
ATP + H2O –> ADP + Pi
What are the advantages to using ATP?
Only one enzyme is needed to release energy through the breaking of one high energy bond
Releases small packets of energy (30.6kJ) when and where it is needed
Common source of energy for different chemical reactions - universal
Easily transported across membranes
What are the disadvantages of using glucose directly instead of ATP?
Many enzymes needed to release energy
Releases large quantities of energy that may not be needed, generating lots of heat
Only releases energy through respiration
Requires proteins to cross a membrane
