3.11. ATP Flashcards
What does ATP mean?
Adenosine Triphosphate
What do cells require energy for?
- Synthesis of molecules e.g. protein synthesis
- Transport of molecules or ions e.g. vesicles from golgi to plasma
- Cellular movement e.g. contraction of cardiac muscle cells
Why do cells require energy?
energy has to be transferred to cellular processes in the right form and right amount.
What is ATP?
The intermediary between energy-yielding and energy-requiring cellular reactions.
What does energy-yielding mean?
Transferring energy out of molecules
What does energy-requiring mean?
Transferring energy into molecules
What does MRS NERG stand for?
M-ovement
R-espiration
S-ensors
N-utrients
E-xcretion
R-eproduction
G-rowth
What is MRS NERG used to describe?
Cellular processes that give out or require ATP
What are the main components of ATP?
- proposed as a universal energy currency
- classified as a NucleoSide Triphosphate
Who proposed ATP was a universal energy currency?
Fritz Albert Lipmann in 1941
What are the components that classify ATP as a nucleoside triphosphate?
- nitrogenous base (adenine)
- sugar ribose
- triphosphate (3 phosphate groups)
How is the nitrogenous base connected to the pentose sugar in a nucleoSide?
through a 1’ glycosidic bond
What is the difference between a nucleoTide and a nucleoSide?
NucleoTides are nucleoSides with ONE phosphate group connected to the 5’ carbon whereas NucleoSides have THREE phosphate groups.
What can ATP also be known as besides an adenosine triphosphate?
phosphorylated nucleoTide.
What happens when bonds are broken or made?
Broken = energy released
Made = energy required
What is the formula involving ATP and what type of reaction is it?
ATP + H20 —> ADP + Pi
This is a hydrolysis reaction.
How much energy is released during the hydrolysis reaction?
30.6 kJ mol-1
What does Pi mean?
inorganic phosphate (on its own)
How does one identify each phosphate group?
1st = γ (gamma)
2nd = β (beta)
3rd = α (alpha)
What is the Krebs Cycle?
Where the ATP formula can be reversed by condensation and made by hydrolysis
What does ADP stand for?
Adenosine diphosphate
How is ATP transferred in ADP + Pi?
The terminal γ phosphate requires little energy to break the weak bond holding it to the middle β phosphate - separating it from the rest and creating Pi.
- When this bond breaking is coupled to another chemical reaction that involves bond making, a large amount of energy is released.
What is coupling?
When the ATP to ADP reaction occurs at the exact time as another bond making reaction - acts as a catalyst.
What is the ratio of ATP to ADP?
Living cells maintain a ratio of ADP to ATP with ATP concentrations five-fold higher than concentration of ADP.
5:1
What is the volume of ATP making mitochondria in a cell?
25% in a non-photosynthetic aerobic eukaryotic cell.
Where is ATP production?
Mitochondria
What are phosphate to phosphate bonds often referred to as?
High-energy bonds
What are the main ATP properties that doesn’t allow for energy storage in cells?
Bonds between the phosphate groups (especially γ) are relatively weak. This means ATP is not used as long term energy stores.
- ATP is not stored in cells, but made and then consumed by cellular reactions (it is an immediate store of energy for cells as energy currency).
What are alternate long term energy stores to ATP (an immediate store)?
lipids and carbohydrates
Why is ATP soluble in water?
As dipoles allow ATP to bond to water molecules.
- This allows ATP to dissolve in the cytoplasm.
- ATP often bound to Mg2+ in the cytoplasm (magnesium ions)
What does being small allow ATP to be?
Allows it to be easily transported around and between cells
How does ATP being hydrolyzed allow energy transfer?
ATP can transfer appropriate amounts of energy into coupled reactions and not waste such energy as heat.
How can ATP be easily regenerated?
As it can easily be remade from ADP and Pi by a condensation reaction.
How much ATP is made in the human body a day?
The human body recycles its own body mass in ATP each day.
