Quiz 2 Pt 1 Flashcards
(27 cards)
• The totality of an organism’s chemical reactions
• is an emergent property of life that arises from orderly interactions between molecules.
• from the Greek metabole, “change”
Metabolism
specific molecule is altered in a series of defined steps, resulting in a certain product. Each step is catalyzed by a specific enzyme, a macromolecule that speeds up a chemical reaction.
Metabolic pathway
release energy by breaking down complex molecules to simpler
compounds
Catabolic pathway
consume energy to
build complicated molecules from simpler ones; they are sometimes called biosynthetic
pathways
Anabolic pathway
the study of how energy
flows through living organisms.
Bio energetics
The study of the energy
transformations that occur in a collection of matter
Thermodynamics
is the portion of a system’s
energy that can perform work when temperature and pressure are uniform throughout the system, as in a living cell.
Free energy
proceeds with a net
release of free energy
Exergonic reaction
is one that absorbs free energy from its surroundings
Endergonic reaction
A cell does three main kinds of work:
Mechanical work
Transport work
Chemical work
the pushing of endergonic
reactions that would not occur
spontaneously, such as the synthesis of polymers from monomers
Chemical work
the pumping of substances across membranes against the
direction of spontaneous movement
Transport work
such as the beating of
cilia, the contraction of muscle cells, and the movement of chromosomes during cellular
reproduction
Mechanical work
the use of an exergonic
process to drive an endergonic one.
Energy coupling
contains the sugar ribose, with the
nitrogenous base adenine and a chain of three phosphate groups (the triphosphate group) bonded to it
ATP (Adenosine Triphosphate)
the transfer of a phosphate group from ATP to some other molecule, such as the reactant.
Phosphorylation
The recipient molecule with the phosphate group
covalently bonded to
Phosphorylated Intermediate
is a macromolecule that acts as a
catalyst
a chemical agent that speeds up a reaction without being consumed by the reaction
Enzymes
The initial investment of energy for starting a reaction — the energy required to contort the reactant molecules so the bonds can break
the amount of energy needed to push the reactants to the top of an energy barrier, or “uphill,” so that the “downhill” part of the reaction can begin.
is often supplied by heat in the form of thermal energy that the reactant molecules absorb from the surroundings
Activation energy
is typically a pocket or groove on
the surface of the enzyme where catalysis occurs
Active site
The tightening of the binding
after initial contact,
Induced fit
Are adjuncts, may be bound tightly to the enzyme as permanent residents, or they may bind loosely and reversibly along with the substrate.
Cofactors
resemble the normal substrate
molecule and compete for admission into the active site
reduce the productivity of enzymes by blocking substrates from entering active sites.
Competitive exhibitors
do not directly compete with the
substrate to bind to the enzyme at the active site
they impede enzymatic reactions by binding to another part of the enzyme
Non competitive inhibitors
