Biol 1010 Chapter 4 Review - Metabolism and Cellular Respiration

Flashcards covering biological energy transfer, enzyme regulation, and the steps of cellular respiration including Glycolysis, the Citric Acid Cycle, and Fermentation.

Metabolism

All reactions collectively occurring at the same time.

Anabolic reactions

Reactions that form bonds to store energy by building something larger from smaller components.

Catabolic reactions

Reactions that break bonds to release energy and turn something large into smaller, more manageable components.

First law of thermodynamics

States that energy is neither created nor destroyed but rather transferred between living organisms.

Second law of thermodynamics

States that some energy is always lost as heat in the transfer of energy.

Potential energy

Stored energy required to make movement possible at a later time.

Kinetic energy

Energy involved in movement.

Chemical energy

Energy found in the covalent bonds of organic molecules that gives the potential to do all the things living organisms need to do.

Endergonic

A type of anabolic reaction where low potential energy reactants are turned into high potential energy products by adding energy.

Exergonic

A type of catabolic reaction where energy is released as covalent bonds are broken.

Enzymes

Proteins that increase the rate at which any reaction occurs, typically ending in ‘-ase’, and are not consumed or used up during the process.

Activation energy

The energy needed to initiate a reaction.

Active site

The specific area on an enzyme where a substrate binds to be changed into a product.

Competitive inhibitors

Molecules similar enough to a substrate that they bind to the active site to prevent the substrate from binding.

Noncompetitive inhibitors

Molecules that bind the enzyme somewhere other than the active site, changing the active site shape and preventing substrate binding.

Feedback inhibition

A process cells use to prevent overproduction of a product by using that product as a competitive or noncompetitive inhibitor for reactions in the series.

Adenosine triphosphate (ATP)

A compact unit of energy, small enough to be managed by an individual cell.

Adenosine diphosphate (ADP)

The molecule formed when one of the three phosphate groups is released from ATP in an exergonic, catabolic reaction.

Glycolysis

A process occurring in the cytoplasm where glucose ($6$ carbon molecule) forms $2$ pyruvates ($3$ carbon molecules) for a net of $2$ ATP.

Transition Step (Pyruvate Oxidation)

The process in eukaryotic cells where pyruvates are converted to acetyl-CoA ($2$ carbon molecule) through the loss of a $CO_2$ molecule and reduction of NAD+ to NADH.

Citric Acid Cycle (Kreb’s cycle)

Metabolic reactions in the mitochondrial matrix where $2$ $CO_2$ molecules are released, and $1$ ATP, NADH, and $FADH_2$ are generated while a $4$ carbon molecule is regenerated.

Oxidative phosphorylation

The final step of cellular respiration occurring in the mitochondrial or plasma membrane that uses electron carriers (NADH and $FADH_2$) to produce the bulk of a cell’s ATP.

Electron transport chain (ETC)

A series of embedded membrane proteins that move electrons, causing them to lose potential energy to move hydrogen ions ($H^+$) and create a concentration gradient.

Oxygen

The final electron acceptor in the electron transport chain that combines with free $H^+$ to generate $H_2O$.

Chemiosmosis

The process where the $H^+$ gradient diffuses through the enzyme ATP synthase to generate large amounts of ATP.

Lactic acid fermentation

An anaerobic process where pyruvate donates electrons back to NADH to produce lactic acid; occurs in many bacteria and animal muscles.

Alcohol fermentation

A process where yeast, in the absence of oxygen, converts carbohydrates into ethanol and $CO_2$.