BIO 120 METABOLISM & ENZYMES
Describe metabolism. The sum of an organism's chemical processes is referred to as its
metabolism. It involves the interactions of molecules inside of a cell. A catabolic process breaks
down bigger molecules like glucose into carbon dioxide and water. The main catalyst for
catabolism is cellular respiration, according to I. Anabolic pathway: Making complex
compounds using energy from cellular respiration. An example of anabolism is the synthesis of
proteins from amino acids. Energy coupling is the process through which energy is moved from
catabolism to anabolism. Energy is the "ability to carry out a task." Photosynthesis is powered by
kinetic energy from the sun. Potential energy is the energy that matter has due to its composition
or location. i. Chemical energy: A form of stored potential energy in molecules.
Energy is transformed by organisms. The part of energy in a system called "free energy" is
capable of doing work. Exergonic reaction: Net energy release (negative) 1. Endergonic
reaction—Net energy absorption in cellular respiration (positive) 1. Cells and the ability to
accomplish workIII. Photosynthesis. Cellsi does three basic sorts of labor. Transporting
chromosomes is mechanical labor. Pumping chemicals against diffusion in transport iii.
Chemical work: polymer synthesis. Adenosine triphosphate (ATP) serves as the source of energy
for this process.
Organisms change energy in many ways. The "free energy" component of a system has the
capacity to perform work. Net energy release from an exergonic reaction (negative) 1. Cellular
respiration's net endergonic response absorption (positive) 1. Cells and their capacity for work
Photosynthesis, in III. Cellsi does three types of work in general. Chromosome transportation
requires mechanical labor. transporting compounds via pumping against diffusion. Polymer
synthesis is a chemical process. The energy source for this procedure is adenosine triphosphate
(ATP).
As another molecule displaces the more reactive phosphate group, the molecule becomes less
stable (or more reactive), and it subsequently becomes more stable. iii. ATP production. 1. ATP
can be produced again. An ADP molecule can be phosphorylated to produce new ATP. 2. By a
process known as dehydration synthesis, energy from catabolism is utilized to rebuild ATP. ATP
+ H2Oi ADP + P. In a biological setting, this process burns 13 kcal/mol of energy. As another
molecule displaces the more reactive phosphate group, the molecule becomes less stable (or
more reactive), and it subsequently becomes more stable. iii. ATP production. 1. ATP can be
produced again. An ADP molecule can be phosphorylated to produce new ATP. 2. By a process
known as dehydration synthesis, energy from catabolism is utilized to rebuild ATP. ADP + P
H2Oi + ATP. In a biological setting, this process burns 13 kcal/mol of energy.
Enzymes are selective, lowering the activation energy while only catalyzing one kind of reaction.
i. Since they only react with particular substrates, enzymes are selective. Its substrates can be
bound by the enzyme. 1. Enzymes are even capable of discriminating between isomers. ii. An
active site is the area of an enzyme where the enzyme binds to its substrate. On the surface of the
enzyme, an active site is often a groove. 1. An enzyme's active site can "close" to grasp its
substrate. iii. The substrate binds to the enzyme and forms an enzyme-substrate complex when it
enters the active site. Ionic and hydrogen connections frequently aid in holding the substrate in
place.
The product is subsequently released, leaving the active site available for more substrates, which
is catalyzed by the variable groups on amino acids. Normally, this occurs so quickly that one
enzyme molecule can interact with 1000 molecules of substrate in a second. a. The metabolic
system can be greatly influenced by a small number of enzymes. f. Regulating enzymes i.
Inhibitors block the entrance of the substrate to the active site. 1. Competitive inhibitors attach to
the active site of the enzyme and prevent the substrate from adhering. 2. Noncompetitive
inhibitors alter the structure of the enzyme by binding at a region other than the active site,
preventing the fuel from interacting with the enzyme there. 3. When a chemical may serve as a
regulator, that is positive suppression.
