Chapter 8 Flashcards
(60 cards)
The term used to describe all of the chemical reactions inside a cell
These chemical reactions provide energy and create substances that sustain life
Metabolism
Is the build up and breakdown of nutrients within a cell
Metabolism
Large molecules are broken down into simple (smaller) ones, RELEASING ENERGY in the process
Small molecules are assembled into longer ones USING ENERGY
Catabolism
Anabolism
Organisms that convert inorganic carbon dioxide into organic compounds _______?
Plants and Cyanobacteria are well known examples
Autotrophs
Rely on more complex organic compounds as nutrients; these are provided to them initially by autotrophs
Escherichia coli is an example of a
Heterotroph
Catabolism is ______ because it releases energy
Anabolism is _________ requires input of energy
Exergonic
Endergonic
Speed up reactions without being altered
Catalysts
Act on a specific substrate and lower the activation energy
Enzymes
Energy source : chemical
Carbon source : inorganic
Examples: hydrogen, sulfur, iron, nitrogen, and carbon monoxide oxidizing bacteria
Chemoautotrophs
Energy source : chemical
Carbon source : organic compounds
Examples : all animals, most fungi, Protozoa, and bacteria
Chemoheterotrophs
Energy source : light
Carbon source : inorganic
Examples : all plants, algae, Cyanobacteria, and green and purple sulfur bacteria
Photo autotrophs
Energy source : light
Carbon source: organic compounds
Examples : green and purple nonsulfur bacteria, heliobacteria
Photoheterotrophs
Reactions that REMOVE electrons from donor molecules, leaving them oxidized are
Those that add electrons to acceptor molecules, leaving them reduced, are
Oxidation reactions
Reduction reactions
Because electrons can move from one molecule to another, oxidation and reduction reactions occur in tandem. These pairs of reactions are called
Oxidation reactions or Redox reactions
Are inorganic ions such as iron (Fe 2+) and magnesium (Mg2+) that help stabilize enzyme conformation and function.
Cofactors
One example of an enzyme that requires a metal ion as a cofactor is the enzyme that builds DNA molecules, ________, which requires a bound zinc (Zn2+) to function.
DNA polymerase
Are organic helper molecules that are required for enzyme action.
Coenzymes
The most common sources of coenzymes are
Dietary vitamins
An enzyme lacking a necessary cofactor or coenzyme is called a _____ and is inactive.
An enzyme with the necessary associated cofactor and coenzyme is called a _____ and is active.
Apoenzyme
Holoenzyme
Is a molecule similar enough to a substrate that it can compete with the substrate for binding to the active site by simply blocking the substrate from blocking
Example: sulfa drugs
Concentration dependent
Competitive inhibitor
Interact with another part of the enzyme (allosteric site) rather than the active site in a process called allosteric inhibition
Non concentration dependent
Non competitive inhibitors
Is a 6 carbon sugar
Glucose
Is the most common pathway for catabolism of glucose
Takes place in cytoplasm of prokaryotic and eukaryotic cells.
Begins with a single six carbon glucose molecule and ends with TWO molecules of a three carbon sugar called pyruvate
Glycolysis
Incoming two carbon acetyl results in the main out puts per turn of two CO2, THREE NADH, ONE FADH2, and One ATP molecules made by substrate level phosphorylation. Two turns of the _________ are required to process all of the carbon from one glucose molecule
Krebs cycle
