Openstax Biology 2eChapter 6

metabolism

term for all of an organism's chemical reactions

cellular respiration

metabolism of glucose

photosynthesis

production of glucose

metabolic pathway

begins with a specific molecule and ends with a product. (i.e. metabolic processes: photosynthesis and cellular respiration).

each step is catalyzed by a specific enzyme

anabolic pathway

consumes energy to build complex molecules from simpler ones.

body builds molecules by forming bonds which store energy in the electrons of said bonds.

synthesis of protein from amino acids is anbolism

catabolic pathway

release energy by breaking down complex molecules into simple compounds.

body breaks down the molecule by breaking the bonds and releasing stored energy in electrons.

cellular respiration is an example.

energy

the ability to work. electrical, light and heat.

Kinectic energy

energy associated with objects in motion

potential energy

energy that has the potential to do work. stored energy.

chemical energy

potential energy in chemical bonds that is released when those bonds are broken.

exergonic

reactions that release energy

catabolic reactions release energy.

cellular respiration- metabolism of glucose

endergonic

requires energy

anabolic reactions require energy

photosynthesis- production of glucose requires energy.

aerobic

type of cellular respiration that contains oxygen.

anaerobic

type of cellular respiration that does not contain oxygen

activation energy

name of energy needed to start chemical reaction.

Law of Thermodynamics

study of energy and energy transfer.

in an open system energy matter can be transferred between system and its surroundings.

biological systems are open systems.

The First Law of Thermodynamics

Energy can be transferred and transformed but it cannot be created or destroyed.

The Second Law of Thermodynamics

During every energy transfer or transformation, some energy is unusable and is often lost as heat.

adenosine triphosphate

ATP, composed of ribose(a sugar), adenine (a nitrogenous base), and three phosphate groups.

energy coupling

managing energy resources by using an exergonic process (release of energy) to drive an endergonic process (requires energy) one.

most energy coupling is mediated by ATP

hydrolysis

breaks bonds in ATP phosphate groups.

energy is released as bonds are broken.

catalyst

chemical agent that speeds up reaction without being consumed by the reaction

enzyme

protein working as a catalyst

-ase

common suffix of enzymes

activation energy curve

enzymes catalyze reactions by lowering the required energy to speed up reaction that would occur eventually

substrate

chemical reactants to which an enzyme binds.

active site

location within enzyme where substrate binds.

enzyme specificity

complimentary fit between the shape of active site and substrate shape.

induced fit

enzymes change shape due to chemical interactions with substrate. the change brings chemical groups of the active site into positions that enhance their ability to catalyze the reaction.

chemical chaos

result if a cell's metabolic pathways were not tightly regulated

competitive inhibitors

bind to the active site of an enzyme, competing with the substrate

non-competitive inhibitors

bind to another part of an enzyme, causing the enzyme to change shape and making the active site less effective.

inhibitors can be toxins, poisons, pesticides

cofactors

non-protein enzyme helpers.

may be inorganic (such as metal in ionic form) or organic

coenzyme

organic cofactor

includes vitamis

coenzymes

ATP

NADH

FADH2

feedback inhibiton

effect of a product of a reaction sequence to decrease its further production by inhibiting the activity of the first enzyme in the pathway that produces it

transition state

a high-energy intermediate state of the reactants during a chemical reaction that must be achieved for the reaction to proceed