Chapter 8 Flashcards
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
Which part of the cell does Oxidative phosphorylation occur ?
Inner mitochondrial membrane for eukaryotes
Inner part of cell membrane of prokaryotes (plasma membrane )
Names of enzymes usually end in ____; grouped based on the reaction they catalyze
Ase
Oxidoreductase
Transferase
Hydrolase
Lyase
Isomerase
Ligase
Oxidation reduction reactions
Transfer functional groups
Hydrolysis
Removal of atoms without hydrolysis
Rearrangements of atoms
Joining of molecules uses ATP
Factors that influence enzyme activity
Temperature
pH
Substrate concentration
Inhibitors
High temperatures and extreme pH _____ proteins
Denature
If the concentration of a substrate is high _______ the enzyme catalyses at its maximum rate
Saturation
The enzymatic activity increases with increasing temperature until the enzyme, a protein, is denatured by heat and inactivated
Temperature
With increasing concentration of substrate molecules, the rate of reaction increases until active sites on all enzyme molecules are filled, at which point the maximum rate of reaction is reached
Substrate concentration
Removal of electrons
Gain of electrons
An oxidation reaction paired with a reduction reaction
Oxidation
Reduction
Redox reaction
In biological systems, electrons and protons are removed at the same time; equivalent to a hydrogen atom.
Oxidation reduction reactions
ATP is generated by the phosphorylation of _____ with the input of energy
ADP
ATP is generated when high energy PO4 is added to ADP
Substrate level phosphorylation
Electrons are transferred from one electron carrier to another along an electron transport chain on a membrane that releases energy to generate ATP
Oxidative phosphorylation
Is the term for the process wherein ATP is generated from ADP using energy derived from the electron chain transport chain
Chemiosmosis
Is the last component of cellular respiration; it comprises a series of membrane associated protein complexes and associated mobile accessory electron carriers.
Electron transport system
Is a series or chemical reactions that resembles a bucket brigade in that electrons from NADH AND FADH2 are passed rapidly from one ETS electron to another
ETS
Is the ability to do work
Energy
Humans
E.coli
Chemoheterotroph
Purple, green non sulfur bacteria
Photohetertroph
Is generated by the phosphorylation of ADP with the input of energy
ATP
In eukaryotic cells, a little bit of ATP is located in the ?
Cytosol
In eukaryotic cells, cellular respiration happens in ?
Mitochondria
In 1. eukaryotic and 2. prokaryotic cells, the electron transport system is located ?
- Mitochondria
- Cell membrane
32-36 ATP are generated in the mitochondria of
Eukaryotic cells
In prokaryotic cells, a little bit of ATP is located in the ?
Cytosol
Prokaryote produce ATP in ?
Cell membrane, the phospholipid bi layer
Series of reactions that produce 4 ATP
Krebs cycle
A series of enzyme reactions
Glycolysis
Uses oxygen as the final electron acceptor
Aerobic respiration
The final electron acceptor (the one having the most positive redox potential) at the end of the ETS is an oxygen molecule that becomes reduced to water by the final ETS
Aerobic respiration
Uses a molecule other than oxygen as the final electron acceptor
Anaerobic respiration
ETS location in prokaryotes:
ETS location in eukaryotes:
Membrane of prokaryotes
Nucleus of eukaryotes
Is a complex protein that acts as a tiny generator, turning by the force of the H+ diffusing through the enzyme, down their electrochemical gradient from where there are many mutually repelling H+ to where there are few H+
ATP synthase
The breakdown of carbohydrates to release energy typically occurs in three principle stages
Glycolysis
Krebs cycle
ETS
The oxidation of glucose to pyruvic acid produces
ATP and NADH
is generated by oxidative phosphorylation
ATP
