Cellular Processes and Metabolism Vocabulary

Vocabulary flashcards covering cellular processes, enzymes, cellular respiration, and protein synthesis based on Chapter 1-8 lecture transcripts.

Enzyme

A protein catalyst that speeds up chemical reactions in cells by lowering the energy needed to get the reaction started.

Substrate

The specific molecule or atom that an enzyme acts upon or works on during a chemical reaction.

Coenzyme

A helper molecule, often synthesized from B vitamins, that assists an enzyme in performing its function.

Redox reaction

An oxidative reduction reaction that involves the movement or transfer of electrons between molecules.

Dehydration reaction

An anabolic chemical reaction that removes water to combine smaller molecules, such as monosaccharides or amino acids, into larger structures.

Hydrolysis

A catabolic chemical reaction that uses water to split or break down large molecules into smaller components.

Metabolism

The sum total of all chemical reactions that take place within the body or inside cells.

Catabolism

The side of metabolism focused on breaking down complex molecules into smaller units to release energy.

Anabolism

The side of metabolism focused on building up larger molecules from smaller components.

Adenosine Triphosphate (ATP)

The primary refined energy currency or cellular fuel synthesized from carbohydrates, proteins, and fats.

Cellular respiration

The metabolic process of refining sugar in the presence of oxygen to produce ATP, releasing $CO_2$ as a byproduct.

Glycolysis

An anaerobic 10-step process occurring in the cytoplasm that splits a six-carbon glucose molecule into two three-carbon pyruvate molecules, yielding a net total of 2 ATP and 2 NADH.

Pyruvate reduction

An anaerobic reaction catalyzed by lactate dehydrogenase that converts pyruvate and NADH into lactate (lactic acid) to recycle $NAD^+$ when oxygen is lacking.

Pyruvate oxidation

An aerobic process occurring in the mitochondria where pyruvate is converted into acetyl CoA, producing $CO_2$ and NADH without directly producing ATP.

Citric acid cycle

An aerobic cyclic metabolic pathway in the mitochondria that uses acetyl CoA to produce 3 NADH, 1 $FADH_2$, 2 $CO_2$, and 1 ATP per cycle.

Electron transport system

An aerobic chain of protein pumps in the mitochondria that receives electrons from NADH and $FADH_2$ to pump $H^+$ ions, transferring electrons to oxygen to form water and produce a large amount of ATP.

ATP synthase

An enzyme in the mitochondria that synthesizes ATP from ADP and phosphate using the flow of $H^+$ ions.

Oxidative phosphorylation

The metabolic process of synthesizing ATP via the flow of hydrogen ions driven by the electron transport chain, using oxygen as the final electron acceptor.

Acetyl CoA

A crucial intermediate molecule produced from pyruvate oxidation or fatty acid breakdown that can enter the citric acid cycle or be assembled into fatty acids for fat storage.

Transcription

The process taking place in the nucleus of a cell where a specific gene sequence on DNA is copied to produce RNA.

Translation

The process taking place at the ribosome where the sequence of RNA is read to assemble amino acids into a protein.

Messenger RNA (mRNA)

The type of RNA that carries the direct copy of genetic instructions from DNA to guide protein synthesis.

Ribosomal RNA (rRNA)

The type of RNA produced in the nucleolus that forms part of the structure of a ribosome along with proteins.

Transfer RNA (tRNA)

The supplier RNA molecule that brings the correct amino acids to the ribosome during protein translation.