Chapter 8 Flashcards
Metabolism
Transforms matter and energy (subject to the law of thermodynamics)
Metabolic pathways are diverse with respect to
- the length of the pathway
- the organization of the pathway
- how the pathway is regulated
Isolated System
Unable to exchange energy or matter with its surroundings
Open System
Energy and matter can be transferred between the system and its surroundings
-Ex: Organisms
First Law of Thermodynamics
Energy cannot be created nor destroyed
- Relates to the amount of energy in the universe
- Ex: Chemical energy in food
- Harness PE to do work
Second Law of Thermodynamics
During every energy transfer, some energy is unusable and often lost in the form of heat
- Reveals efficiency of an energy transformation (does not occur with 100% efficiency)
- Heat (KE)= can be harnessed to do work but only when there is a heat gradient (NOT in cells)
Enzyme Class: Oxidoreductase
other names: Oxidase, Reductase, Dehydrogenase
Reaction Type: Electron Transfer
-Catalyzes reaction where 1 molecule is oxidized and the other is reduced
Enzyme Class: Transferase
Reaction Type: Transfers functional groups from one molecule to another
(ex: taking terminal phosphate from ATP and tranferring it to a portion of a protein, which is the sodium potassium pump)
Enzyme Class: Hydrolases
Reaction Type: Hydrolysis of one molecule into more than one molecule
- Catalyzes hydrolytic cleavage
- Found within lysosome
- Perform optimally in acidic environments
- Can be used to break covalent bonds
Enzyme Class: Lyase
Reaction Type: Removal/addition of a group into a molecule
-Removal/Addition rather than transport –> used to create modified molecule
Enzyme Class: Isomerase
Reaction Type: Movement of functional group within a molecule
- Related to isomers
- Catalyze arrangement of bonds within a single molecule
- Used to move functional groups within a molecule, rather than one molecule to another
Enzyme Class: Ligase
Reaction Type: Joins two molecules together
- Energy dependent process
ex: extend 2 DNA molecules together through phosphodiesther bonds
Cofactors
Nonprotein enzyme helpers
- May be inorganic (metal in ionic form) or organic (vitamins)
- Coenzyme= organic cofactor
Q) All of the following are ways to regulate an enzyme except:
A. Dephosphorylation by a phosphatase
B. The binding of a substrate
C. Allosteric activation
D. Addition of a phosphate group
E. All of the above are mechanisms for regulation
A) E. All of the above are mechanisms for regulation
Catabolic Pathways
- Large molecules are broken down into smaller ones
- Generate energy by breaking down larger molecules