Module 11 Flashcards
Cell Cycle
The series of steps that take place as a eukaryotic cell grows, replicates its DNA, and divides to produce daughter cells.
Mitosis
The separation of replicated chromosomes to produce daughter cells that are genetically identical to the parental cell. Also called karyokinesis.
Circular Chromosomes
DNA in prokaryotes.
Linear Chromosomes
DNA in eukaryotes.
Interphase
The time between two successive M phases. Lasts around 10-14 hours.
Daughter Cell
The cell produced after cell division.
G2 Phase
The second gap phase. Cell prepares for M phase.
G0 Phase
Separate from G1 phase. No active preparation for cell division. Occurs in cells that do not actively divide ex. liver cells.
Template Strand
The strand of DNA used as a guide to synthesize new DNA.
Daughter Strand
The new strand of DNA that is synthesized.
Helicase
Unwinds the parental double helix at the replication fork. Allows a single strand of DNA to be available for complementary base-pairs to be added by DNA polymerase.
Topoisomerase
Works up stream of the replication fork. Changes the supercoiled state of DNA, caused by the unwinding of the double helix at the replication fork.
RNA Primase
Synthesizes a short piece of RNA that is complementary to a sequence of the DNA parental strand. Is needed so the DNA polymerase can add DNA bases to the growing chain.
Lagging Strand
The strand that grows away from the replication fork and synthesizes discontinuously as fragments.
DNA Ligase
Joins the fragments of DNA together by completing the sugar-phosphate backbone of the new DNA.
Origin of Replication
Any point on a DNA molecule at which DNA synthesis is initiated.
Telomere
The ends of the linear chromosomes. 5’ TTAGGG 3’ in humans.
Germ Cells
A reproductive cell that produces gametes (sperm or eggs).
Somatic Cells
A non-reproductive cell and the most common type of cell in the body of a multicellular organism.
Haploid
A cell with one complete set of chromosomes (n).
Binary Fission
The process of cell division in prokaryotes.
Cytokinesis
The division of the cytoplasm into two daughter cells.
M Phase
The time during which the parent cell divides into two daughter cells (includes cytokinesis).
Parent Cell
The original cell before cell division.
G1 Phase
First gap phase. Increase in cell size and protein content. Preparing the cell for S phase. Synthesis and activation of regulatory proteins.
S Phase
The synthesis phase, replication of DNA.
DNA Replication
Duplicating DNA.
Replication Fork
The site where the parental DNA strands separate as the DNA duplex unwinds.
Semiconservative Replication
One strand is from the parent and the other is from the daughter.
Single-Strand Binding Protein
Binds to the single-stranded regions of the parental strands. Prevents the parental strands from coming back together.
DNA Polymerase
Adds bases to the nucleotide strand in the 5’ to 3’ direction. Can also correct mistakes that may occur during replication.
Leading Strand
The strand that grows towards the replication fork and synthesizes continuously.
Okazaki Fragments
The short, discontinuous pieces found in the lagging strand.
Proofreading
The process in which a DNA polymerase can immediately correct its own errors by excising and replacing a mismatched base.
Replication Bubble
A region formed by the opening of a DNA duplex at an origin of replication which has a replication fork at each end.
Telomerase
An enzyme that can extend the ends of the chromosome to address chromosome shortening. Is a ribonucleoprotein (protein-RNA complex). Carries its own primer (template DNA) and has reverse transcriptase activity (RNA —> DNA).
Stem Cells
An undifferentiated cell that can undergo an unlimited number of mitotic divisions and differentiate into any of the large number of specialized cells.
Homologous Chromosomes
Pairs of chromosomes, matching in size and appearance, that carry the same set of genes. One of each pair was received from the mother and the other from the father.
Diploid
A cell with two complete sets of chromosomes (2n).
Centrosome
The microtubule-organizing centers for animal cells. Are duplicated and begin to migrate to opposite poles during prophase. Part of the mitotic spindle.