Bisc 220 exam 1 rita

Intramolecular Bonds

Bonds that occur within a molecule, primarily ionic and covalent bonds.

Ionic Bond

A type of bond formed through the transfer of electrons, typically between a metal and a nonmetal, leading to the formation of positively and negatively charged ions.

Covalent Bond

A type of bond formed when two atoms share one or more pairs of electrons.

Electronegativity

The tendency of an atom to attract electrons towards itself when forming a bond.

Hydrogen Bond

A weak bond formed between a hydrogen atom and an electronegative atom, significant in the properties of water.

pH Scale

A scale used to determine the acidity or alkalinity of a solution based on the concentration of free hydrogen ions.

Hydrophilic

Substances that are 'water-loving', often polar and soluble in water.

Hydrophobic

Substances that are 'water-fearing', often non-polar and insoluble in water.

Octet Rule

A rule stating that atoms tend to bond in such a way that they have eight electrons in their valence shell, resulting in a stable electron configuration.

Isotope

Atoms of the same element that have different numbers of neutrons, leading to different atomic masses.

Functional Groups

Specific groups of atoms within molecules that are responsible for the characteristic chemical reactions of those molecules.

DNA

Deoxyribonucleic Acid, the hereditary material in almost all living organisms, consisting of two strands that form a double helix.

RNA

Ribonucleic Acid, a nucleic acid present in all living cells that plays a role in coding, decoding, regulation, and expression of genes.

Transcription

The process by which the genetic information encoded in DNA is copied into messenger RNA (mRNA).

Translation

The process by which the sequence of nucleotides in mRNA is translated into an amino acid sequence, forming proteins.

Gene Expression

The process by which information from a gene is used to synthesize functional gene products, typically proteins.

Endocytosis

The process by which cells internalize substances from their external environment by engulfing them in a vesicle.

Exocytosis

The process by which cells expel materials from the cell via vesicle fusion with the plasma membrane.

Affinity Chromatography

A technique used to separate proteins based on their specific interactions with a stationary phase in a column.

ELISA

A common laboratory technique used to detect and quantify proteins, especially antibodies, in a sample.

Western Blotting

An analytical technique used to detect specific proteins in a sample using gel electrophoresis followed by transfer to a membrane.

Induced Fit Model

A model describing how enzymes modify their shape to fit substrates to catalyze a reaction.

Knockout Model

An experimental organism where a specific gene has been completely disabled or 'knocked out'.

Knock-in Model

An experimental organism created by adding a new gene to the organism's genome.

Tonicity

The relative concentration of solutes dissolved in solution which determine the direction and extent of diffusion.

Covalent versus Ionic vs Hydrogen Bonds

Covalent bonds involve sharing electrons, ionic bonds involve transfer and attraction of charged ions, and hydrogen bonds are weak attractions based on partial charges.

Intramolecular Bonds

Bonds that occur within a molecule, including ionic and covalent bonds.

Ionic Bond

A type of bond formed when a metal donates an electron to a nonmetal, resulting in charged ions (cations and anions). Example: Sodium Chloride (NaCl).

Covalent Bond

A type of bond formed when two nonmetals share electrons to balance their valence shells. Example: Water (H2O).

Hydrogen Bond

A weak bond that occurs between a hydrogen atom and a nonmetal atom, owing to electrostatic forces.

Octet Rule

The principle that atoms are most stable when they have eight electrons in their valence shell.

Isomer

Compounds with the same chemical formula but different structural arrangements.

Cation

A positively charged ion formed when an atom loses one or more electrons.

Anion

A negatively charged ion formed when an atom gains one or more electrons.

Electronegativity

A measure of the tendency of an atom to attract a bonding pair of electrons.

Functional Groups

Specific groups of atoms within molecules responsible for the characteristic chemical reactions of those molecules.

Polar Covalent Bond

A covalent bond where electrons are shared unequally, leading to partial positive and negative charges.

Universal Solvent

A term used to describe water, which can dissolve many substances due to its polar nature.

Hydrogen Ion (H+)

A positively charged ion formed when a hydrogen atom loses its electron.

Hydroxide Ion (OH-)

A negatively charged ion consisting of one oxygen atom and one hydrogen atom.

Isotope

Atoms of the same element with different numbers of neutrons, which can be radioactive.

Lewis Dot Structure

A diagram that shows the bonding between atoms and the lone pairs of electrons in a molecule.

Gel Electrophoresis

A laboratory method used to separate DNA, RNA, or proteins based on their size and charge.

Polymerase Chain Reaction (PCR)

A technique used to amplify a specific segment of DNA, generating thousands to millions of copies of a particular DNA sequence.

CRISPR-Cas9

A revolutionary technique for editing genes with high precision by using a specific guide RNA to direct the Cas9 enzyme to a target sequence.

In Situ Hybridization

A technique used to detect specific nucleic acid sequences within fixed tissues and cells.

Northern Blotting

A method used to study gene expression by detecting RNA in a sample; combines gel electrophoresis and in situ hybridization.

Green Fluorescent Protein (GFP)

A protein used as a fluorescent marker to visualize the expression of a protein of interest in cells.

Knock-in

A genetic modification technique where a new piece of DNA is inserted into a specific location within the genome.

Knock-out

A genetic modification technique that involves the deletion or inactivation of a gene to study its function.

Necessary and Sufficient

Terms used to describe the roles of a gene in producing a specific phenotype; necessary means the gene must be present for the phenotype, while sufficient means the gene alone can produce the phenotype.

Taq polymerase

A heat-stable enzyme used in PCR to synthesize new DNA strands by extending primers.

Transcription

The process of creating a messenger RNA strand from a DNA template.

RNA Polymerase

The enzyme that adds RNA-based nucleotides during transcription.

mRNA splicing

The process of excising introns from pre-mRNA to produce a mature mRNA transcript.

Introns

Non-coding regions of the transcript that are removed during RNA splicing.

Exons

The remaining sections of mRNA that code for proteins after splicing.

Poly-A tail

A series of adenine nucleotides added to the 3’ end of an mRNA transcript.

Guanosine cap

A modified guanosine nucleotide attached to the 5’ end of an mRNA transcript.

Translation

The process of protein synthesis from mRNA that occurs at the ribosome.

Ribosome

The cellular structure where translation takes place, composed mostly of rRNA.

tRNA

Transfer RNA that delivers amino acids to the ribosome based on the mRNA codon.

Start codon

The codon that initiates translation, usually corresponding to the amino acid methionine.

Stop codon

The codon that terminates translation.

Phases of transcription

Initiation, Elongation, Termination.

Phases of translation

Initiation, Elongation, Termination.

Passive Transport

Transport mechanisms that do not require energy and allow molecules to move along their concentration gradient.

Active Transport

Transport mechanisms that require energy to move molecules against their concentration gradients.

Simple Diffusion

Process of a molecule moving from an area of high concentration to an area of low concentration without assistance.

Facilitated Diffusion

Diffusion process that involves specialized protein channels to assist the movement of molecules.

Protein Pumps

Transport proteins that use energy to move a molecule against its concentration gradient, typically using ATP.

Cotransporters

Transport proteins that use the energy from moving one molecule along its concentration gradient to move another molecule against its concentration gradient.

Exocytosis

The process of transporting materials out of the cell via vesicles.

Endocytosis

The process of transporting materials into the cell via vesicles.

Clathrin-mediated Endocytosis

A specific form of endocytosis that relies on the clathrin protein to form a coated vesicle.

Tonicity

The ability of a surrounding solution to cause a cell to gain or lose water.

Hypertonic Solution

A solution that causes a cell to lose water, leading to cell shrinkage.

Adherens Junctions

Cell junctions that recruit microfilaments (actin) and are common in epithelial tissue.

Tight Junctions

Cell junctions that fuse two cell membranes together, preventing leakage; common in epithelial tissue.

Gap Junctions

Specialized intercellular connections that allow for the passage of ions and small molecules between cells.

Desmosomes

Cell junctions that provide structural integrity to tissues by anchoring cells together.

Autocrine Signaling

A type of chemical signaling where a cell signals to itself.

Paracrine Signaling

A type of chemical signaling where a cell signals to nearby neighboring cells.

Endocrine Signaling

A type of chemical signaling where cells signal to distant targets through the bloodstream.

Piezo Channels

Ion channels that respond to mechanical stress, providing sensory information about pressure.

Gene Expression

The process of regulating when certain genes are transcribed into (m)RNA.

Transcription Factors

Special proteins in eukaryotic cells that can promote or prevent gene expression by binding to specific DNA regions.

Repressor

A protein that inhibits gene expression by binding to the operator region of DNA.

Operon

A region of DNA in prokaryotes that contains a regulatory gene, a promoter, and structural genes.

Lac Operon

An operon found in prokaryotic cells that regulates the digestion of lactose.

Trp Operon

An operon in prokaryotic cells that regulates the synthesis of the amino acid tryptophan.

Activators

Transcription factors that promote gene expression by binding to the promoter region.

Intracellular Homeostasis

The maintenance of stable internal conditions within a cell.

Allolactose

A structural isomer of lactose that binds to the lac repressor and allows gene expression.

Transcription Factor Complex

A group of more than one transcription factor required for regulating gene expression.

Endosymbiotic Theory

The leading theory explaining the evolution of modern eukaryotic cells, proposing that ancestral prokaryotic cells contributed to the formation of internal membrane-bound organelles.

Transcription

The process of gene expression where DNA is transcribed to mRNA, occurring in the nucleus for eukaryotic cells and in the cytosol for prokaryotic cells.

Translation

The process of protein synthesis, where mRNA is translated into polypeptides at the ribosome, occurring in both eukaryotic and prokaryotic cells.

Endomembrane System

A system of membrane-bound organelles involved in the transport and modification of proteins and macromolecules, including processes like exocytosis and endocytosis.

Rough Endoplasmic Reticulum (Rough ER)

A type of endoplasmic reticulum with ribosomes on its surface involved in synthesizing membrane proteins.