Chapter 5 Metabolic Processes and Enzymes

These flashcards cover key terms and concepts relevant to metabolic processes, enzymes, and energy transformation as discussed in Chapter 5 of the lecture.

Oxidation

Loss of electrons from a substrate, often involving the removal of protons.

Reduction

Gain of electrons, resulting in a decrease in oxidation state.

Photoheterotrophs

Organisms that obtain chemical energy from light.

Chemoheterotrophs

Organisms that gain chemical energy by oxidizing/reducing organic compounds.

Autotrophs

Organisms that can use inorganic sources like CO2 as carbon sources.

Apoenzyme

The protein portion of an enzyme that must be activated by cofactors.

Cofactor

A non-protein component that assists in enzyme activation.

Coenzyme

An organic cofactor that aids enzyme function.

Holoenzyme

The complete active enzyme, consisting of apoenzyme plus cofactor.

Collision theory

Chemical reactions occur when atoms collide, requiring activation energy.

Competitive inhibitor

A substance that competes with the normal substrate for the active site of an enzyme.

Non-competitive inhibitor

An inhibitor that decreases enzyme activity without competing for the active site.

NAD+

A coenzyme that acts as an electron carrier during glucose breakdown.

FAD

Another coenzyme that functions similarly to NAD+ in electron transport.

Glycolysis

A metabolic process occurring with or without oxygen, yielding ATP and NADH.

Fermentation

An anaerobic process that releases energy from organic molecules by oxidation.

Substrate-level phosphorylation

A method of ATP production that occurs in glycolysis.

Final electron acceptor in fermentation

An organic molecule within the cell that accepts electrons.

Lactic acid

A fermentation product used in yogurt and cheese production.

Alcohol fermentation

Conversion of pyruvate to ethanol, used in biofuel production.

pH change in fermentation

Acid production from catabolizing carbohydrates can lead to pH changes.

38 ATP

The total ATP molecules generated during complete glucose metabolism in bacteria.

Krebs cycle

A metabolic pathway that processes acetyl-CoA, generating electron carriers.

Electron transport chain (ETC)

A series of protein complexes that transfer electrons and produce ATP.

NADH and ATP production

1 NADH results in 3 ATP; FADH2 results in 2 ATP.

Proton motive force

A gradient created by H+ ions across the membrane that drives ATP synthesis.

Chemiosmosis

The process of generating ATP using the electrochemical gradient created by protons.

Amphibolic pathways

Metabolic pathways that serve both catabolic and anabolic functions.

Energy release from ATP

Occurs via breaking high energy phosphate bonds.

Cell division requires ATP

Energy must be expended for cellular growth and division.

Beta oxidation

The metabolic pathway for breaking down fatty acids for energy.

Anaerobic respiration

A process where nitrate or sulfate ions serve as final electron acceptors.

Aerobic respiration

A process where oxygen is the final electron acceptor, producing CO2 and H2O.

CO2 production from glucose

Carbon from glucose is lost during Krebs cycle or before, converting pyruvate.

ATP synthase

An enzyme complex that synthesizes ATP during chemiosmosis.

Enzyme activity

Depends on optimal conditions such as pH and temperature.

Hydrogen ions (H+)

Protons that create a gradient used for ATP synthesis.

Proton concentration gradient

A difference in proton levels across the membrane that drives ATP production.

Intermediates in glycolysis

Compounds used as building blocks for biosynthetic pathways.

Active transport

Requires ATP to move substances across a membrane against their concentration gradient.

Cofactor activation

Cofactors enhance enzyme activity by enabling apoenzymes to function.

High-energy phosphate bond

A bond that stores energy, broken to release energy for cellular processes.

Pyruvate

The end product of glycolysis, which can enter Krebs cycle or fermentation.

Acetyl-CoA

A key intermediate used in the Krebs cycle, derived from pyruvic acid.

Organic molecules fermentation

Organic compounds serve as final electron acceptors in anaerobic fermentation.

Yogurt production

A fermentation process that produces lactic acid from lactose.

Ethanol fermentation

Conversion of pyruvate to ethanol and CO2, significant in brewing.

Inhibitor types

Competitive and non-competitive inhibitors alter enzyme activity differently.

Energy from fats

Fats can be metabolized to provide energy when carbohydrates are scarce.

Role of NADH

Carries high-energy electrons to the ETC to facilitate ATP production.

Carbon sources for bacteria

Bacteria can utilize lipids and proteins when carbohydrates are scarce.

Krebs cycle byproducts

Produced during glucose metabolism, including NADH and ATP.

Glycolysis yield

Each glucose molecule yields 2 ATP and 2 NADH through glycolysis.

Final electron acceptor in aerobic respiration

Oxygen acts as the electron acceptor in aerobic metabolic processes.

Intermediate metabolites

Substances that can enter glycolysis or Krebs for energy.

Metabolic pathways

Series of enzymatic reactions processing substrates for energy or building blocks.

Reduction of pyruvate

Pyruvate can be reduced via fermentation to regenerate NAD+.

Biosynthetic pathways

Utilize intermediates from metabolic pathways for cellular assembly.

Hydrogen ion pump

H+ ions are moved to create a proton motive force across membranes.

Charge gradients

Uneven distribution of charges across membranes beneficial for ATP synthesis.

Energy yield comparison

Aerobic respiration yields more energy than anaerobic pathways.

Electron carriers

Molecules that transfer electrons within the electron transport chain.

Sulfate as electron acceptor

Used in anaerobic respiration when oxygen is absent.

Oxygen in respiration

Serves as the terminal electron acceptor in aerobic pathways.

Lactate from fermentation

Produced by reducing pyruvate during anaerobic conditions.

ATP production from NADH

Each NADH can theoretically produce up to 3 ATP in the ETC.

Fatty acid oxidation

Lipid breakdown that occurs to provide energy through beta oxidation.

Energy for macromolecule synthesis

ATP needed for the biosynthesis of lipids, proteins, and nucleic acids.

Chemical signaling in cells

Some ATP is used for signaling pathways in cellular communication.

NAD+ regeneration

Essential for glycolysis to continue during fermentation processes.

Acid production during fermentation

Results from the breakdown of carbohydrates, measurable by pH change.

Decrease in enzyme activity by inhibitors

Both types of inhibitors reduce the rate of enzyme-catalyzed reactions.

Pyruvate role in metabolism

A key intermediary in metabolic pathways related to both energy production and biosynthesis.

Oxidative phosphorylation

The process that generates the majority of ATP in cellular respiration.

Krebs cycle ATP yield

Direct ATP production, typically minimal compared to oxidative phosphorylation.

Electron transport efficiency

High energy electron carriers enhance the ability of the ETC to produce ATP.

Fermentative products variety

Different microorganisms can produce a variety of fermentation by-products.

Organic substrates in fermentation

Sugars are typically the main energy source for fermentation processes.

Proteins in cellular metabolism

Can be utilized for energy through catabolic processes when carbohydrates are limited.

Carbon cycling in bacteria

Bacteria play a significant role in recycling carbon through metabolic processes.

Metabolite interconversion

Metabolites can be interconverted depending on cellular needs for energy or building blocks.

Deamination

The process of removing an amine group from amino acids for energy use.

Final products of anaerobic metabolism

Gases like CO2 and organic acids are produced during anaerobic processes.

Hydrolytic reactions

Involve breaking down larger molecules into smaller components using water.

Competitive inhibition examples

Substances that resemble the normal substrate and bind to the active site.

Enzyme feedback inhibition

A mechanism where the end product inhibits an earlier step in the pathway.

Facilitated diffusion

Process by which substances move across membranes with the help of transport proteins.

Electron transport chain location

Embedded in the plasma membrane of prokaryotes and mitochondrial membrane of eukaryotes.

Altering enzyme activity

By changing substrate concentration, temperature, or pH.

Calvin cycle association

Pathway used by autotrophs to fix inorganic carbon dioxide.

Byproducts of fermentation

Organic products generated as a result of anaerobic metabolism.

Strains of bacteria

Different strains can produce different end products via fermentation pathways.

Sugar metabolism

Involves various pathways, including glycolysis, fermentation, and the Kreb's cycle.

Aerobic metabolism advantages

More efficient due to higher energy yield from the complete oxidation of glucose.

Essential cofactors

Minerals like zinc or iron are critical for enzymatic reactions.

Pathway interconnectivity

Different metabolic pathways influence one another for efficient cellular function.

Cellular respiration

The overall process by which cells convert biochemical energy from nutrients into ATP.

Hydrogen pump function

Forms proton gradients that drive ATP synthesis.

Energy conversion processes

Bacteria convert various substrates into usable energy forms.

Microorganisms in fermentation

Utilized in various biotechnological applications for food, fuel, and pharmaceuticals.