Cell Division, Cellular Transport, Peptidoglycan, and Protein Synthesis

Vocabulary flashcards summarizing key terms related to cell division (mitosis & meiosis), cellular transport mechanisms, bacterial peptidoglycan structure, and protein synthesis.

Cell Division

Process by which a parent cell splits to produce daughter cells, transferring identical genetic information for growth, repair, or reproduction.

Cell Cycle

Ordered series of events that a cell goes through to grow and divide, culminating in two new cells.

Mitosis

Type of cell division that produces two genetically identical diploid daughter cells.

Interphase

Non-dividing portion of the cell cycle where the cell grows, replicates DNA, and prepares for mitosis (G1, S, G2).

G1 Phase

Interphase stage of cellular growth, organelle production, and protein synthesis.

S Phase

Interphase stage in which DNA replication occurs, creating two identical sets of genetic material.

G2 Phase

Interphase stage of protein synthesis and DNA integrity checkpoint before mitosis.

G0 Phase

Quiescent state where cells exit the cycle and do not divide (e.g., neurons).

Prophase

First mitotic phase: chromatin condenses into chromosomes, spindle forms, nuclear envelope dissolves.

Metaphase

Mitotic phase in which chromosomes align at the cell’s equatorial plate.

Anaphase

Mitotic phase where sister chromatids separate and move to opposite poles.

Telophase

Mitotic phase where chromosomes decondense, nuclear envelopes re-form, and spindle disappears.

Cytokinesis

Division of cytoplasm that physically separates the two daughter cells.

Diploid

Cell condition with two sets of chromosomes (2n).

Haploid

Cell condition with one set of chromosomes (n).

Replication

Exact duplication of the cell’s DNA prior to division.

Centrosome

Organelle containing two centrioles; organizes the mitotic spindle in animal cells.

Centriole

Cylinder of microtubules that helps form spindle fibers during cell division.

Microtubule

Hollow protein filament that shapes cells, moves organelles, and forms spindle fibers.

Spindle Fiber

Microtubule structure that attaches to chromosomes and moves them during mitosis or meiosis.

Chromatin

DNA–protein complex that condenses to form chromosomes during cell division.

Chromatid

One of two identical DNA strands of a duplicated chromosome joined by a centromere.

Diffusion

Net movement of particles from high to low concentration without energy input.

Simple Diffusion

Unassisted movement of small, non-polar molecules across a membrane.

Facilitated Diffusion

Passive transport of molecules via membrane proteins (channels or carriers).

Osmosis

Diffusion of water across a semipermeable membrane toward a higher solute concentration.

Polymer

Large molecule composed of repeating subunits (monomers).

Passive Transport

Movement of substances across membranes without energy expenditure.

Active Transport

Energy-requiring movement of substances against their concentration gradient via transport proteins.

Antiport Pump

Active transporter moving two substances in opposite directions using ATP.

Symport Pump

Co-transporter that uses the downhill movement of one solute to drive another uphill.

Endocytosis

Active process in which the cell membrane engulfs material to bring it inside as vesicles.

Exocytosis

Vesicle-mediated export of substances from the cell to the extracellular space.

Peptidoglycan

Polymer of sugars and amino acids forming the bacterial cell wall; also called murein.

N-acetylglucosamine (NAG)

Sugar monomer that alternates with NAM within peptidoglycan chains.

N-acetylmuramic acid (NAM)

Sugar monomer in peptidoglycan that carries short peptide chains.

Bactoprenol

Membrane carrier molecule that transports peptidoglycan precursors across the bacterial plasma membrane.

DNA Transcription

Synthesis of mRNA using DNA as the template.

Translation

Ribosomal process that converts mRNA codons into a specific polypeptide chain.

Messenger RNA (mRNA)

RNA copy of a gene that conveys genetic information from nucleus to ribosome.

Transfer RNA (tRNA)

Adaptor molecule that carries specific amino acids to the ribosome during translation.

Polypeptide

Linear chain of amino acids produced during translation; may fold into a protein.

Protein

Folded, functional macromolecule composed of one or more polypeptide chains.

Meiosis

Two-stage cell division that produces four genetically unique haploid gametes.

Homologous Chromosomes

Chromosome pair—one maternal, one paternal—with the same genes but possibly different alleles.

Synapsis

Pairing of homologous chromosomes during prophase I of meiosis.

Tetrad

Structure of four chromatids formed by paired homologs during meiosis I.

Chiasma

Visible point where homologous chromatids exchange segments during crossing over.

Crossing Over

Reciprocal exchange of genetic material between homologous chromatids, increasing genetic diversity.

Gamete

Haploid reproductive cell (sperm or egg) produced by meiosis.

Reduction Division

Nickname for meiosis I, when chromosome number is halved.

Leptotene

Early prophase I stage where chromatin condenses into thin chromosomes.

Zygotene

Prophase I substage when homologous chromosomes begin pairing (synapsis).

Pachytene

Prophase I substage characterized by complete synapsis and the onset of crossing over.

Diplotene

Prophase I substage where homologs begin to separate but remain connected at chiasmata.

Diakinesis

Final prophase I substage; chromosomes fully condensed, spindle apparatus forms.

Metaphase I

Meiotic stage where paired homologs align on the metaphase plate.

Anaphase I

Meiotic stage where homologous chromosomes (not chromatids) move to opposite poles.

Telophase I

Stage completing meiosis I; nuclei may form and cytokinesis produces two haploid cells.

Interkinesis

Brief resting phase between meiosis I and meiosis II without DNA replication.

Metaphase II

Meiotic stage where individual chromosomes align at the equator of each haploid cell.

Anaphase II

Meiotic stage where sister chromatids finally separate and move to opposite poles.

Telophase II

Final meiotic stage forming nuclei around chromatids; cytokinesis yields four haploid cells.