Metabolism, Energy and ATP Flashcards
What is metabolism?
All the chemical reactions that take place within a living organism
What is metabolism usually controlled by?
Enzymes
What is a metabolic pathway?
A sequence of enzyme controlled reactions
What does the product of one reaction act as in a metabolic pathway?
The substrate for the next
What is the last substance produced known as?
End-Product inhibition/feedback regulation which may be used by another part of the cell
What are the 2 types of metabolic pathways?
Anabolism
Catabolism
What is anabolism?
Build up of larger, more complex molecules from smaller, simple ones
What do anabolic reactions require?
Energy
What is catabolism?
Breakdown of complex molecules into simple ones
What do catabolic reaction release?
Energy
2 examples of anabolic, condensation reactions
-Amino Acids into peptides
-Nucleotides into RNA
2 examples of catabolic, hydrolysis reactions
-Starch into glucose
-Triglycerides into fatty acids and glycerol
How can enzymes be grouped together?
Depending on types of reactions they catalyse
Hydrolase Enzymes
Control hydrolysis reactions
Oxidoreductase Enzymes
Control redox reactions
Transferase Enzymes
Move whole chemical groups e.g Amino Acids
Isomerase Enzymes
Change the shape of a molecules (creating an isomer)
What is energy?
Ability to do work
What are the 2 states of energy?
-Kinetic
-Potential
Kinetic Energy
-Energy of motion
-Moving objects perform work by making other objects move
Potential Energy
-Stores energy
-An object that is not moving may still have the potential to do work as it has “potential energy”
Energy Simple Facts
-Can be changed from one store to another
-Cannot be created or destroyed
-Is released and not produced
-Measured in Joules
What is energy needed for?
-Metabolism (anabolism esp)
-Movement within organism and of the organism
-Active Transport
-Maintenance, repair and cell division
-Homeostasis (body temperature esp)
-Secretion of chemicals e.g. hormones
Where does energy come from?
See Notes for Diagram
What is the main energy currency of living cells?
Adenosine Triphosphate (ATP)
What is ATP?
A small water soluble molecule which is therefore easily transported around the cell
How does ATP store energy?
As chemical potential energy
What is the structure of ATP?
Adenine (Nitrogenous Base)
Ribose Sugar
3 Phosphates
How does ATP store energy?
-Each phosphate groups are negativity charged so straining to get away from each other
-Covalent bonds holding P groups together are easily broken
-When covalent bonds break, phosphate is released along with 30.6 kJ mol-1 of energy for each for the first 2 phosphates
What is unique about the conversion of ATP to ADP?
Is reversible
How is the ATP to ADP conversion reversible?
Energy from respiration can be used to combine ADP with a phosphate to re-form ATP
What is the ATP to ADP conversion known as?
Phosphorylation
What type of reaction is Phosphorylation?
Condensation reactions
What is Phosphorylation catalysed by?
ATP synthase or ATPase
How is energy put in and out of Phosphorylation?
Out-by condensation (Phosphorylation)
In-by hydrolysis
Why is ATP a bad long term energy storage molecule?
Due to the instability of ATP’s phosphate bonds
What type of energy source is ATP?
Immediate
ATP as an immediate energy source
-Cell doesn’t need large quantities of ATP
-Maintains only a few seconds supply
-ATP is rapidly reformed so a little goes a long way
