Osmosis, Water Movement, and DNA to Protein (Transcription & Translation) – Vocabulary Flashcards

Vocabulary flashcards covering osmosis, tonicity, and DNA-to-protein processes (transcription and translation) based on the lecture notes.

Osmosis

The passive movement of water across a semi-permeable membrane from a region of higher water activity to lower water activity.

Tonicity

The ability of a solution to affect the fluid volume and pressure inside a cell.

Hypertonic

A solution with higher solute concentration than inside the cell; water exits the cell, causing shrinkage.

Hypotonic

A solution with lower solute concentration than inside the cell; water enters the cell, causing swelling.

Isotonic

A solution with equal solute concentration to the cell; water movement is balanced and the cell remains normal.

Plasma osmolarity

The concentration of solutes in blood plasma used to assess fluid shifts and guide IV therapy.

Homeostasis

The body's ongoing maintenance of stable internal conditions, including water distribution among cells.

DNA

Deoxyribonucleic acid; a polymer of nucleotides that stores genetic information.

RNA

Sugar is Ribose

Nucleic acids

Biological molecules (DNA and RNA) assembled from nucleotides.

Nucleotide

A unit of nucleic acids consisting of a nitrogenous base, a sugar, and a phosphate group.

Deoxyribose

Sugar in DNA.

Adenine (A)

A purine base that pairs with thymine in DNA and with uracil in RNA.

Cytosine (C)

A pyrimidine base that pairs with guanine.

Guanine (G)

A purine base that pairs with cytosine.

Thymine (T)

A pyrimidine base that pairs with adenine in DNA.

Uracil (U)

A pyrimidine base that pairs with adenine in RNA (replaces thymine in RNA).

Transcription

The process of synthesizing RNA from a DNA template, guided by RNA polymerase.

RNA polymerase

The enzyme that synthesizes RNA during transcription by reading the DNA template.

Promoter

A specific DNA sequence that signals where transcription begins.

Initiation (transcription)

RNA polymerase binds promoter and begins RNA synthesis.

DNA unwinding

The separation of DNA strands to expose the template strand for transcription.

Template strand

The DNA strand used as the template for RNA synthesis (3'→5').

Elongation

Addition of RNA nucleotides to extend the growing RNA transcript (5'→3').

Termination

RNA polymerase releases the pre-mRNA when a termination signal is reached.

pre-mRNA

The initial RNA transcript containing exons (coding) and introns (non-coding) before processing.

Exons

Coding regions of a gene that remain in mature mRNA.

Introns

Non-coding regions removed by splicing during mRNA processing.

Splicing

The process of removing introns and joining exons to form mature mRNA.

Mature mRNA

Processed mRNA containing exons, with a 5' cap and 3' poly-A tail, ready for export.

Nuclear export

Transport of mature mRNA from the nucleus to the cytoplasm through nuclear pores.

Translation

Process of decoding mRNA to synthesize a polypeptide at the ribosome.

mRNA

Messenger RNA; the RNA template that carries codons for amino acids.

tRNA

Transfer RNA; carries specific amino acids to the ribosome during translation.

rRNA

Ribosomal RNA; structural and catalytic component of ribosomes.

Ribosome

Cellular machinery that translates mRNA into a polypeptide; has A, P, E sites.

Start codon

The first codon of translation; AUG in mRNA.

Methionine

The amino acid encoded by the start codon AUG and used to begin polypeptide synthesis.

Codon

A three-nucleotide sequence on mRNA that specifies an amino acid.

Anticodon

A three-nucleotide sequence on tRNA that pairs with a complementary mRNA codon.

Stop codons

Codons that terminate translation: UAA, UAG, and UGA.

Post-translational modifications

Changes to a polypeptide after translation, such as phosphorylation or glycosylation.

Phosphorylation

Addition of a phosphate group to a molecule, often regulating activity.

Glycosylation

Attachment of sugar groups to a protein, affecting folding and function.

Protein folding

The process by which a polypeptide assumes its three-dimensional structure.

Targeting to cellular locations

Sorting and directing proteins to specific cellular compartments after synthesis.