3.1.6 ATP Flashcards
State reasons why organisms need energy to function
-metabolism: the sum of all of the chemical reactions that take place within an organism
-anabolic reactions: building larger molecules from smaller ones
-active transport: to move molecules against the concentration gradient
-movement: (muscle contraction) within and of organisms
-maintenance, repair and division: of cells and organelles
-production of proteins
-maintenance of body temperature: of birds and mammals through respiration
Describe the function of ATP
It is used to transfer energy in all energy-requiring processes in cells. This means it provides the energy needed to drive many processes and reactions in cells that require energy.
Describe the bonds between phosphate groups in ATP
-high energy bonds
-unstable bond with a low activation energy, so are easily broken
-this releases a considerably large amount of energy
What does ATP stand for?
Adenosine tri-phosphate
What is BMR?
Basal metabolic rate- the measure of the energy required to keep the body functioning at rest
Why is BMR different for males and females?
-differences in muscle mass, as muscle cells require more energy to function
Describe the structure of ATP?
-Another type of nucleic acid
-a nucleotide formed from ribose, adenine and 3 phosphate groups
-adenine is a nitrogenous base and ribose is a pentose sugar
Describe how ATP releases energy
-energy released during respiration or photosynthesis is transferred to ATP
-the hydrolysis of ATP is an exothermic reaction, which therefore means energy is released
-This reaction is catalysed by the enzyme ATP hydrolase
-this produces adenosine di-phosphate, an inorganic phosphate, and releases energy
-the inorganic phosphate produced can be used to phosphorylate other molecules
-the reactants are ATP and water
Describe how ATP is synthesized from ADP
-a condensation reaction between ADP and an inorganic phosphate
-this requires energy as is is an endothermic reaction
-thus reaction produces ATP and a water molecule
-The reaction is catalysed by the enzyme ATP synthase
Why is ATP a useful energy source?
-the hydrolysis of ATP is quick and efficient when energy is required
-a useful amount of energy is released per ATP molecule
-the hydrolysis of ATP can be coupled to energy-requiring reactions within cells.
Give the 3 ways in which ATP is made?
1) Substrate level phosphorylation- as a byproduct of other reactions
2) Oxidative phosphorylation- formed during respiration
3) Photophosphorylation- formed during photosynthesis
Define phosphorylation
The addition of a phosphate group to a molecule, which makes it more reactive
What is AMP and ADP?
-Adenosine mono-phosphate has one phosphate group
-Adenosine di-phosphate has two phosphate groups
Give the 7 features of ATP that make it a suitable energy source
-energy is released in small, manageable quantities when hydrolysed
-hydrolysis involves a single reaction so energy is therefore released immediately
-it can be readily reformed and resynthesised
-it is not lost from, and does not leave the cell
-phosphorylates (adds phosphates) to other molecules which makes them more reactive and lowers their activation energy
-it uses energy that is released from other reactions
-it can be readily moved, stored or broken down when needed
