Human Anatomy and Physiology Chapter 03 Part D: Cells: The Living Units – Vocabulary

Vocabulary flashcards covering the cell cycle, DNA replication, and protein synthesis.

Cell cycle

The series of stages that cells go through to divide, including interphase and the mitotic (M) phase.

Interphase

Growth and metabolic activities; DNA replication occurs; consists of G1, S, G2 (G0 for cells that permanently cease dividing).

G1

First gap phase; vigorous growth and metabolism.

S (synthesis)

DNA replication occurs during this phase.

G2

Second gap phase; preparation for division and final growth.

G0

Phase in which cells permanently cease dividing.

Semiconservative replication

DNA replication in which each new DNA molecule has one old strand and one new strand.

Replication fork

The point where DNA strands separate and replication occurs.

DNA replication

The process of copying the cell’s DNA prior to division.

Nucleotide

The basic unit of DNA and RNA, composed of a sugar, phosphate, and a base.

Deoxyribose

The sugar component of DNA.

Phosphate

Part of the DNA backbone linking sugars together.

Adenine (A)

DNA base that pairs with thymine (and with uracil in RNA).

Thymine (T)

DNA base that pairs with adenine.

Cytosine (C)

DNA base that pairs with guanine.

Guanine (G)

DNA base that pairs with cytosine.

Complementary base pairing

A pairs with T (or U in RNA); C pairs with G.

Double helix

The twisted ladder structure of DNA formed by base pairing.

Mitosis

Nuclear division producing two identical nuclei; stages: prophase, metaphase, anaphase, telophase.

Prophase

First stage of mitosis; chromosomes condense, nucleolus disappears, spindle forms.

Metaphase

Chromosomes align at the metaphase plate; spindle fibers attach to centromeres.

Anaphase

Sister chromatids split and move toward opposite poles.

Telophase

Nuclei form around each set of chromosomes; chromosomes de-condense.

Cytokinesis

Division of cytoplasm; contractile ring forms cleavage furrow; two daughter cells result.

M phase

Mitotic phase; includes mitosis and cytokinesis.

Checkpoints

Control points (e.g., G1 checkpoint) that regulate progression of the cell cycle.

Messenger RNA (mRNA)

RNA that carries genetic information from DNA to ribosomes for protein synthesis; produced by transcription.

Ribosomal RNA (rRNA)

Structural component of ribosomes, where protein synthesis occurs.

Transfer RNA (tRNA)

Carries amino acids and contains anticodons that pair with mRNA codons during translation.

Transcription

Process of copying DNA into an mRNA sequence.

Translation

Process of decoding mRNA to synthesize a polypeptide (protein).

Codon

A three-base sequence in mRNA that codes for an amino acid or a stop signal.