lecture_11_full_3

Cellular Respiration

The process by which cells convert glucose into energy (ATP) through glycolysis, Krebs cycle, and oxidative phosphorylation.

Glycolysis

The first phase of cellular respiration that breaks down glucose into two molecules of pyruvate, producing a net gain of 2 ATP.

Krebs Cycle

A series of chemical reactions in cellular respiration that produces NADH and FADH2 while releasing carbon dioxide as a byproduct.

Electron Transport Chain

A series of protein complexes in the inner mitochondrial membrane that transfer electrons and pump protons to create an electrochemical gradient.

Oxidative Phosphorylation

The process of ATP production linked to the electron transport chain and the final acceptor of electrons, oxygen.

Proton Gradient

An electrochemical gradient created by the pumping of protons across a membrane during the electron transport chain.

Fermentation

The metabolic process that regenerates NAD+ by converting pyruvate into lactic acid or ethanol when oxygen is not available.

Allosteric Regulation

A regulation mechanism whereby an enzyme's activity is modified by the binding of an effector molecule at a site other than the active site.

Feedback Inhibition

A regulatory mechanism in which the end product of a metabolic pathway inhibits an earlier step in the pathway to prevent overproduction.

Codon

A sequence of three nucleotide bases in mRNA that specifies a particular amino acid in a protein.

RNA Polymerase

An enzyme that synthesizes RNA from a DNA template during transcription.

Exons

Coding segments of a gene that are transcribed into mRNA and expressed as proteins.

Introns

Non-coding segments of a gene that are removed during RNA processing.

Alternative Splicing

A process that allows a single gene to code for multiple proteins by including or excluding certain exons during mRNA processing.

tRNA (transfer RNA)

A type of RNA that carries amino acids to the ribosome during protein synthesis.

Polycistronic mRNA

Bacterial mRNA that encodes multiple proteins, allowing for the translation of several proteins from a single transcript.

Monocistronic mRNA

Eukaryotic mRNA that encodes only one protein and is translated to produce a single polypeptide.

Stop Codons

Codons in mRNA that signal the termination of protein synthesis.

Nucleosome

The structural unit of chromatin, consisting of a segment of DNA wrapped around a core of histone proteins.

Histones

Basic proteins that assist in the packaging of DNA into nucleosomes, helping to form chromatin.

Supercoiled DNA

Form of DNA that is tightly wound and compacted, commonly found in prokaryotic cells.