Outcome 2: BC Pathways, Enzymes Flashcards
What is cell metabolism?
All chemical reactions taking place inside a living cell
What are the two types of major reactions that occur in cells?
Anabolic and Catabolic
What is a anabolic reaction?
An endergonic reaction where molecules are joined together with the help of ATP (endothermic condensation reaction)
What is a catabolic reaction?
An exergonic reaction where molecules are broken apart, and it releases energy (exothermic spontaneous reaction)
What is a biochemical pathway?
Where products of the first step become the reactants in the next step, this continues until a final product is reached
What is a substrate?
Substance where enzyme will act
What is an enzyme?
A globular protein that acts as a biological catalyst
How does a chloroplast produce oxygen and glucose?
carbon dioxide + water –light energy–> oxygen + glucose
How does a mitochondria produce carbon dioxide and ATP?
oxygen + glucose —-> carbon dioxide + ATP + energy produced
Is cellular respiration endothermic or exothermic?
Exothermic
Is photosynthesis endothermic or exothermic?
Endothermic
What is ADP?
adenosine diphosphate (di=2)
What is ATP?
adenosine triphosphate (tri=3)
What is the difference between ADP and ATP?
ADP has had its third phosphate broken off to produce energy.
What is the broken off phosphate from ATP called?
Pi (subscript under ADP)
How is ADP involved in cellular respiration?
The reaction means the phosphate is reattached to form ATP (30 or 32 ADP involved in reaction)
What does a catalyst do?
Lowers the amount of energy (activation energy) required for a reaction to proceed
Why can catalysts be reused?
Because they are not changed or consumed in the reaction
What is the lock and key model?
The substrate fits correctly into the enzyme (this forms a enzyme substrate complex)
What is the induced fit model?
enzyme changed shape slightly to fit substrate
How can enzymes be used to regulate biochemical pathways? (5 points)
- regulate availability
- regulate levels of cofactors/coenzymes
- regulate levels of other enzymes
- introduce inhibitors
- change environmental factors (e.g. temp, pH)
What is the active site?
Where a substrate binds to an enzyme
What is a cofactor?
Inorganic molecule e.g. metal ions
What is a coenzyme?
non-protein organic substances that carry molecules to enzymes
What is the loaded version of ADP?
ATP
What is the loaded version of NAD+?
NADH
What is the loaded version of FAD?
FADH
What is the loaded version of NADP+?
NADPH
What is the unloaded version of ATP?
ADP
What is the unloaded version of NADH?
NAD+
What is the unloaded version of FADH?
FAD
What is the unloaded version of NADPH?
NADP+
How are coenzymes loaded?
oxidation reactions
How are coenzymes unloaded?
reduction reactions
How is reaction speed increased (collision theory)?
- Increase temp
- Increase concentration
- Maintaining enzyme substrate specificity
Why is there a limit on how much you can increase the temperature to increase reaction speed?
Past a certain temperature the enzymes will be denatured and no longer work
What does a enzyme inhibitor do?
Disrupts normal reaction pathway between enzyme and substrate
What does a irreversible inhibitor do?
Forms strong covalent bonds that causes permanent attachment
What does a reversible inhibitor do?
Forms weak bonds, temporary attachments
What does a competitive inhibitor do?
Binds to the enzymes active site and blocks substrate
How can an competitive inhibitor be counteracted?
By adding more substrate
What does a non competitive inhibitor do?
Binds to allosteric site with causes a change in the active site to no longer able to fit the substrate
Why can’t adding more substrate increase rate of reaction with non competitive inhibitors?
Because its not in direct competition with the substrate
