lecture_11_full 3

biology

Cellular Respiration

The process by which cells convert glucose and oxygen into energy, carbon dioxide, and water.

Glycolysis

The breakdown of glucose into two molecules of pyruvate, yielding a small amount of ATP and NADH.

Pyruvate Oxidation

The process where pyruvate is converted into acetyl-CoA before entering the Krebs Cycle.

Krebs Cycle

Also known as the citric acid cycle, a series of enzymatic reactions that produces NADH and FADH2 for the Electron Transport Chain.

NAD+

An electron carrier that is reduced to NADH during glycolysis and the Krebs Cycle.

NADH

The reduced form of NAD+, which carries electrons to the Electron Transport Chain.

FADH2

An electron carrier similar to NADH, produced during the Krebs Cycle.

Electron Transport Chain (ETC)

A series of protein complexes in the mitochondrial membrane that transfer electrons, creating a proton gradient.

Oxidative Phosphorylation

The process of ATP production in the mitochondria, driven by the electron transport chain and the proton gradient.

Proton Gradient

A difference in proton concentration across a membrane, which is used to drive ATP production.

Aerobic Respiration

A metabolic process that requires oxygen to produce ATP.

Fermentation

An anaerobic process that generates ATP without oxygen, often resulting in byproducts like lactic acid or ethanol.

Allosteric Regulation

Regulation of an enzyme's activity through the binding of molecules at sites other than the active site.

Feedback Inhibition

A process where the end product of a metabolic pathway inhibits an earlier step in the pathway.

Phosphofructokinase (PFK)

An important regulatory enzyme in glycolysis inhibited by ATP and activated by ADP.

Central Dogma of Molecular Biology

The flow of genetic information from DNA to RNA to protein.

Transcription

The process by which DNA is copied into RNA.

Translation

The synthesis of proteins using the information in mRNA.

Ribosome

The cellular structure that synthesizes proteins by translating mRNA.

tRNA

Transfer RNA that carries amino acids to the ribosome for protein synthesis.

mRNA

Messenger RNA that conveys genetic information from DNA to the ribosome.

Amino Acid

The building blocks of proteins, specified by sequences of three nucleotides (codons) in mRNA.

Codon

A sequence of three nucleotides on mRNA that specifies a particular amino acid.

Stop Codon

A codon that signals the termination of protein synthesis.

Start Codon

The codon that signals the start of protein synthesis, usually AUG.

Initiation Complex

The assembly of ribosomal subunits, mRNA, and the initiator tRNA at the start of translation.

Elongation

The process of adding amino acids to the growing polypeptide chain during translation.

Termination

The conclusion of protein synthesis when a stop codon is reached.

Introns and Exons

Introns are non-coding regions of a gene, while exons are the coding regions that remain in the mature mRNA.

Alternative Splicing

The process by which different combinations of exons are joined together to produce different mRNAs from the same gene.

RNA Processing

Post-transcriptional modifications of RNA, including capping, polyadenylation, and splicing.

Histones

Proteins that package and order DNA into structural units called nucleosomes.

Nucleosome

A structural unit made of DNA wound around histone proteins.

Chromatin

The complex of DNA and proteins that forms chromosomes within the nucleus.

Supercoiling

The over-winding or under-winding of DNA, affecting its structure and function.

DNA Polymerase

An enzyme that synthesizes DNA from nucleotides, using a template strand.

Primase

An enzyme that synthesizes a short RNA primer to initiate DNA synthesis.

Ligase

An enzyme that joins together DNA fragments by forming phosphodiester bonds.

Exonuclease

An enzyme that removes nucleotide residues from the ends of a DNA strand.

Endonuclease

An enzyme that cuts DNA at internal sites, not at the ends.

Transcription Factor

Proteins that help initiate and regulate transcription by binding to specific DNA sequences.

RNA Splicing

The editing of the RNA transcript to remove introns and join exons together.

Gene

A segment of DNA that encodes for a protein or functional RNA.

Genome

The complete set of genes or genetic material present in a cell or organism.

Promoter

A DNA sequence that initiates transcription of a particular gene.

Enhancer

A regulatory DNA sequence that increases the likelihood of transcription of a particular gene.

Silencer

A DNA sequence that can downregulate gene expression.

Transcription Bubble

The region of unwound DNA where transcription occurs.

Elongation Factor

Proteins that assist in the elongation phase of translation.

Release Factor

A protein that binds to the stop codon during termination of translation.

Polypeptide

A chain of amino acids linked by peptide bonds, which folds into a functional protein.

Cofactors

Non-protein chemical compounds that are required for enzyme activity.

Substrate

The reactant that an enzyme acts on.

Nucleotide

The basic building block of nucleic acids, consisting of a sugar, phosphate, and nitrogenous base.

Base Pairing

The specific hydrogen bonding between nitrogen bases in DNA and RNA (A with T/U and G with C).

Antiparallel

Describing the opposite orientation of DNA strands in a double helix.

Replication Fork

The area where the DNA double helix is unwound during the process of DNA replication.

Origin of Replication

The specific sequence in DNA where replication begins.

Semiconservative Replication

The method of DNA replication in which each new strand is composed of one old and one new strand.

DNA Ligase

An enzyme that joins DNA strands together by forming phosphodiester bonds.

Exon

The coding region of a gene that is expressed in the final RNA product.

Intron

The non-coding region of a gene that is removed during RNA processing.

Mitochondrial Matrix

The space within the inner membrane of a mitochondrion, where the Krebs Cycle occurs.

Intermembrane Space

The space between the inner and outer membranes of mitochondria, significant for the proton gradient.

Aerobic Conditions

Situations characterized by the presence of oxygen.

Anaerobic Conditions

Situations in which oxygen is absent.

Chemiosmosis

The movement of protons across a membrane, generating ATP via ATP synthase.

ATP Synthase

The enzyme that creates ATP from ADP and inorganic phosphate, utilizing the proton gradient.

Glucose

A simple sugar that is an important energy source for living organisms.

Entropy

A measure of disorder or randomness in a system, often discussed in the context of energy transformations.

Metabolic Pathway

A series of chemical reactions occurring within a cell.

Catabolism

The breakdown of complex molecules to produce energy.

Anabolism

The synthesis of complex molecules from simpler ones, requiring energy.

Redox Reaction

A chemical reaction involving the transfer of electrons from one molecule to another.

GTP

Guanosine triphosphate, a molecule similar to ATP that serves as an energy source.

Zygote

The fertilized egg cell formed by the union of a sperm and an egg.

Haploid

A cell having a single set of chromosomes.

Diploid

A cell containing two complete sets of chromosomes.

Allele

A variant form of a gene.

Phenotype

The observable physical or biochemical characteristics of an organism.

Genotype

The genetic constitution of an organism.

Mutation

A change in DNA sequence that can affect genetic information and function.

Carbohydrates

Biomolecules composed of carbon, hydrogen, and oxygen, serving as energy sources.

Proteins

Large biomolecules made of amino acids, essential for the structure, function, and regulation of the body's cells.

Lipids

Hydrophobic organic molecules, including fats and oils, that are important for cell membranes.

Nucleic Acids

Biomolecules that store and transfer genetic information, primarily DNA and RNA.

Saturated Fat

A type of fat containing a high proportion of saturated fatty acid molecules.

Unsaturated Fat

A type of fat that is liquid at room temperature and contains one or more double bonds between carbon atoms.

Peptide Bond

The bond formed between amino acids in a protein.

Polymerase Chain Reaction (PCR)

A technique used to amplify small segments of DNA.

Gel Electrophoresis

A method for separating nucleic acids or proteins based on size and charge.

Bacterial Transformation

The process by which bacteria take up exogenous DNA from their environment.

Vesicle Transport

The movement of materials into and out of the cell via vesicles.

Endocytosis

The process of taking material into the cell by means of infolding or extending the cell membrane.

Exocytosis

The release of substances from a cell when vesicles fuse with the cell membrane.

Cell Cycle

The series of phases that cells go through as they grow and divide.

Mitosis

A type of cell division where one cell divides to produce two identical daughter cells.

Meiosis

A specialized form of cell division that reduces the chromosome number by half, creating four haploid cells.

Cytokinesis

The process where the cytoplasm of a parental cell divides into two daughter cells.

Signal Transduction

The process by which a cell responds to signaling molecules.