Chapter 6+7 - Introduction to Metabolism (Enzymes) and Cellular Respiration/Fermentation Flashcards
can't be bothered to split them up now, maybe that can be a weekend project
what is metabolism?
All chemical reactions within a cell that keep the cell and body as a whole alive and healthy
What is a metabolic pathway?
Reactant –> O –> O –> Product
A specific molecule is altered in a series of defined steps, where each step is catalyzed by an enzyme. This makes a product.
What reactions RELEASE energy? (ana or cata bolic)
Catabolic! (like a catastrophe)
What reactions CONSUME energy? (c or a)
Anabolic
What reactions BUILD STUFF?
Anabolic (because exo and endo thermic are for losers who don’t care about entropy, which I should definitely start caring about before AP Chem)
What reactions BREAK stuff?
Catabolic
Is photosynthesis ana or cata bolic?
Anabolic - builds sugars
Is cellular respiration ana or cata bolic?
Catabolic
Do catabolic, anabolic, both, or neither require enzymes to catalyze reactions?
Both
Why do organisms need constant energy?
Power energy requiring reactions like anabolic stuff
What is ΔG?
Gibbs free energy
ΔG = ΔH - ΔS (ΔS is entropy, like choices but honestly I don’t think we need to know so we’re just gonna not)
If ΔG is negative, will the reaction go spontaneously? What is this called?
Yasss - Exergonic - energy exits the system and the reactants are more energetic than the products
If ΔG is positive, will the reaction go spontaneously? What is this reaction called?
Nah bro - Endergonic - energy enters the system and products are more energetic than the reactants
Is photosynthesis exer or ender gonic?
Endergonic - requires energy input (this is the same as endothermic except get rid of the concept of breaking/making - reverse that spit)
Is cellular respiration exer or ender gonic?
Exergonic - releases energy (that’s the whole point)
How do organisms get energy for reactions?
Photosynthesis requires sunlight, we respire, organic products of photosynthesis are used
Label an atp molecule.
OOO-pentose-Adenine
OOO - phosphates held together by phosphoanhydride bonds
Pentose - 5 carbon sugar called Ribose
Adenine - nitrogenous base
When breaking a phosphoanhydride bond, what is the reaction?
Hydrolysis
ATP + H2O –> ADP + Pi + Energy
(adp is adenosine di phosphate, pi is a phosphate)
What is the bond holding together the third phosphate and the rest of the ATP molecule?
Terminal phosphate bond
T or F: When the terminal phosphate bond is broken, energy is absorbed
False. Released. It’s exergonic.
What is Energy Coupling?
Using an exergonic reaction to power an endergonic reaction.
How is ATP reaction coupled?
Energy from catabolism is used to phosphorylate (add phosphate to) ADP, which creates ATP. Then, hydrolysis breaks that ATP down, releasing energy for endergonic processes.
Why is energy coupling advantageous for an organism?
This allows reactions to have a negative net ΔG, allowing the reaction to happen spontaneously.
Describe glutamine reaction coupling.
Glutamic Acid (stable) + ATP –> Phosphorylated Glutamic acid (unstable) –> Glutamine + ADP + Pi
What happens to phosphorylated molecules?
They get unstable and react spontaneously
What is a shared intermediate in reaction coupling?
The product of one reaction that is used as a reactant for another reaction
Why are enzymes considered catalysts?
They speed up biochemical reactions in living organisms without being a reactant
What is activation energy>
The initial energy input to bring molecules to their transition state so they have a higher energy level and can break bonds.
T or F - enzymes decrease Ea required to reach transition state and break bonds
True. Transition state ΔG also decreases.
T or F - Enzyme specificity is a thing for all enzymes
This one will trip you up - yesn’t. Some enzymes have specific active sites that will catalyze the reactions of one specific substrate as they fit together like a lock and key. Other enzymes will mold to the shape of the enzyme (induced fit) and can accept multiple substrates, but they won’t be catalyzing ALL the reactions in the cell, just a couple.