DNA Structure, Replication, Protein Synthesis, Cell Cycle, and Mitosis

Vocabulary practice flashcards reviewing DNA structure, nucleotide components, replication, protein synthesis, the cell cycle, mitosis stages, stem cell differentiation, and cancer biology.

DNA (Deoxyribonucleic Acid)

A nucleic acid biomolecule composed of the elements carbon, hydrogen, oxygen, nitrogen, and phosphorus ($\text{C, H, O, N, P}$) organized into repeating monomer units called nucleotides that carries genetic instructions.

Nucleotide Components

The monomer unit of nucleic acids, consisting of three essential parts: 1. Phosphate group, 2. Nitrogenous base, and 3. Deoxyribose (pentose) sugar.

DNA Double Helix Anatomy

The structural components of a DNA molecule: A represents a complete nucleotide, B is the deoxyribose sugar, C is the phosphate group, D is a nitrogenous base, and E represents the hydrogen bond holding complementary bases together.

Nitrogenous Bases (DNA)

The four nitrogen-containing molecular bases in DNA nucleotides: adenine ($\text{A}$), thymine ($\text{T}$), cytosine ($\text{C}$), and guanine ($\text{G}$).

Base-Pairing Rules (DNA)

The rule dictating that adenine pairs specifically with thymine ($\text{A} - \text{T}$) and cytosine pairs specifically with guanine ($\text{C} - \text{G}$).

DNA Replication

The process occurring inside the nucleus of eukaryotic cells prior to division, where parent template strands (A and B) separate to synthesize two identical daughter DNA molecules with complementary strands (X and Y).

Helicase

The enzyme that unwinds and unzips the double-stranded DNA helix during DNA replication.

DNA Polymerase

The primary enzyme responsible for synthesizing new DNA strands by attaching matching complementary nucleotides to the exposed template strands.

Uracil

A nitrogenous base that is absent in DNA and unique to RNA, where it pairs complementarily with adenine.

RNA (Ribonucleic Acid)

A single-stranded nucleic acid containing ribose sugar and the bases adenine, cytosine, guanine, and uracil that assists in copying DNA's genetic code and synthesizing proteins.

Central Dogma of Biology

The principle describing the flow of genetic information: DNA is transferred into RNA, which is transferred into protein.

Codon

A sequence of three consecutive mRNA nucleotides that specifies a single amino acid during protein synthesis.

mRNA Codon Wheel

A decoding wheel read from the innermost circle to the outermost rim to translate a three-nucleotide mRNA codon into its corresponding amino acid.

Cell Differentiation

The biological process in which unspecialized stem cells differentiate into specialized cell types, such as muscle cells, blood cells, nerve cells, cardiac cells, liver cells, and intestinal cells.

Cell Cycle Phases

The recurring sequence of cell growth and division consisting of Interphase (A: $G_1$, B: S phase, C: $G_2$) and M phase (D: Mitosis and Cytokinesis).

S Phase (Synthesis)

The stage of Interphase during which a cell replicates its complete set of nuclear DNA.

$G_0$ Phase

A non-dividing resting state outside the active cell cycle where cells perform everyday metabolic functions without preparing for division.

Cancer

A disease of the cell cycle characterized by uncontrolled cell division and tumor growth when cell cycle checkpoints fail or are bypassed.

Interphase

The longest period of the cell cycle where the cell grows, duplicates organelles, and replicates its DNA while the nuclear envelope remains intact.

Prophase

The first active phase of mitosis where chromatin condenses into distinct visible chromosomes, centrioles separate, and the nuclear membrane begins breaking down.

Metaphase

The mitotic stage where spindle fibers align chromosomes along the center equator (metaphase plate) of the cell.

Anaphase

The stage of mitosis where sister chromatids separate at the centromere and are pulled toward opposite poles of the cell by contracting spindle fibers.

Telophase and Cytokinesis

The final stages of cell division in which new nuclear membranes reform around separated chromosomes and the cytoplasm divides, producing two individual daughter cells.

Mitosis

A process of nuclear division occurring only in somatic (body) cells that produces two genetically identical diploid cells for growth, tissue repair, and replacing worn-out cells.