Chapter 14 - Key Concepts & Review Points Flashcards
Different organisms use different strategies for capturing free energy from their environment and can be classified by their requirement for ____________.
oxygen
Mammalian nutrition involves the intake of macronutrients (____________, ____________, and ____________) and micronutrients (____________ and ____________).
proteins carbohydrates lipids vitamins minerals
A(n) ____________ is a series of enzyme-catalyzed reactions, often located in a specific part of the cell.
metabolic pathway
The flux of material through a metabolic pathway varies with the activities of the enzymes that catalyze ____________.
irreversible reactions
These flux-controlling enzymes are regulated by ____________, ____________, ____________, and ____________.
allosteric mechanisms
covalent modification
substrate cycling
changes in gene expression
Organisms capture the free energy released on degradation of nutrients as “high-energy” compounds such as ________, whose subsequent breakdown is used to power otherwise endergonic reactions.
ATP
ATP hydrolysis can be coupled to a(n) ____________ such that the net reaction is favorable.
endergonic reaction
Phosphoryl groups are transferred from compounds with ________ phosphoryl group-transfer potentials to those with ________ phosphoryl group-transfer potentials.
high
low
The ____________ in acetyl-CoA is a “high energy” bond.
thioester bond
The electron carriers NAD+ and FAD accept electrons from ____________ and transfer them to other compounds.
reduced metabolites
The Nernst Equation describes the thermodynamics of ____________.
oxidation-reduction reactions
The reduction potential describes the tendency for an oxidized compound to ________ electrons (become reduced).
gain
Free energy and reduction potential are related: the greater the reduction potential, the ____________ the free energy and the more favorable the reaction.
more negative
The free energy released from catabolic oxidation reactions is used to drive ____________ reactions.
endergonic anabolic
____________ is the intake and utilization of food to supply free energy and raw materials.
nutrition
____________ organisms obtain their free energy from compounds synthesized by chemolithotrophic or photoautotrophic organisims.
heterotrophic
Near-equilibrium reactions are ____________, whereas reactions that function far from equilibrium serve as regulatory points and render metabolic pathways ____________.
reversible
irreversible
Flux through a metabolic pathway is controlled by regulating the activities of the enzymes that catalyze its ____________.
rate-determining steps
The free energy of the “high-energy” compound ATP is made available through cleavage of one or more of its ____________.
phosphoanhydride bonds
A(n) ____________ reaction such as ATP or PPi hydrolysis can be coupled to a(n) ____________ reaction to make it more favorable.
exergonic
endergonic
Substrate-level phosphorylation is the synthesis of _________ from ________ by phosphoryl group transfer from another compound.
ATP
ADP
The common product of carbohydrate, lipid, and protein catabolism is ____________, a “high-energy” thioester.
acetyl-CoA
The coenzymes ________ and ________ are reversibly reduced during the oxidation of metabolites.
NAD+
FAD
The Nernst Equation relates the _____________ of a redox reaction to the ____________ and ____________ of the electron donors and acceptors.
electromotive force
standard reduction potentials
concentrations
Electrons flow spontaneously from the ____________ member of a redox couple with the more ____________ reduction potential to the ____________ member of the redox couple with the more ____________ reduction potential.
reduced
negative
oxidized
positive
