Flashcards in Chapter 8: Metabolism Deck (25)
Name the two types of reactions
Catabolic - breakdown pathways, releases energy
Anabolic - biosynthetic pathways, requires energy
CHE & ADE
What is Potential Energy?
Stored energy waiting to be used
What is Kinetic Energy?
Energy that an object has because of its movement
First law of thermodynamics
Energy cannot be created nor destroyed
Second law of thermodynamics
Energy transformations are not 100% efficient
Which do you think contains the most potential energy?
C. A phospholipid
D. A triacylglycerol
D. It has more bonds, therefore it's more efficient to store a lot of energy.
Exergonic reactions ________ energy.
In terms of spontaneity, exergonic reactions are ________.
Endergonic reactions ______ energy.
In terms of spontaneity, endergonic reactions are __________.
Which of the following is an endergonic reaction?
A. Synthesis of a polypeptide from amino acids
B. Diffusion of oxygen molecules across a plasma membrane
C. Digestion of starch into its component glucose molecules
D. Formation of hydrogen bonds between water molecules
A. Synthesis of a polypeptide is dehydration, which is endergonic.
What is energy coupling?
1. Energy transferred from catabolic -> anabolic
2. Energy transferred from exergonic -> endergonic
How do you make sure energy is not lost during a transfer?
Through the energy carrier, ATP.
Where is energy stored in ATP?
In the covalent bonds between the phosphates
When ATP is hydrolysized, the energy release powers an __________ reaction.
What are enzymes?
- catalysts that speed a reaction
- not consumed by the reaction
- are reusable
- many of them are proteins
Ending in -ase
In terms of Activation Energy, exergonic reactions have _____ energy overall than when they started.
In terms of Activation Energy, endergonic reactions have _____ energy overall than when they started.
Enzymes _______ the activation energy.
True or False
Enzymes decrease the energy of the products to make endergonic reactions exergonic reactions.
False. Enzymes do not change the energy of products or reactants.
Explain the 5 steps of how enzymes do their work.
1. Substrates enter the active site.
2. Substrates are held in the active site due to their shape.
3. Substrates undergo intermolecular forces in the substrate complex and are converted into products.
4. The products (substrates) now have a different shape and are released.
5. The active site is now available for new substrates.
What is normal binding?
When the substrate goes directly to the active site of an enzyme without any interference.
What is competitive inhibition?
When a competing substrate goes into the active site and the original substrate doesn't bind.