Molecular Biology of the Cell by Bruce Alberts, Alexander Johnson, Julian Lewis, David Morgan, Martin Raff, Keith Roberts, Peter Walter by by Bruce Alberts, Alexander Johnson, Julian Lewis, David Morg

Glossary G:13
free-energy change (∆G) see ΔG.
FRET see fluorescence resonance energy transfer
Frizzled Family of cell-surface receptors that are seven-pass
transmembrane proteins that resemble GPCRs in structure
but do not generally work through the activation of G proteins.
Activated by Wnt binding to recruit the scaffold protein
Dishevelled, which helps relay the signal to other signaling
molecules.
fungus (plural fungi) Kingdom of eukaryotic organisms that
includes the yeasts, molds, and mushrooms. Many plant
diseases and a relatively small number of animal diseases are
caused by fungi.
fusion protein Engineered protein that combines two or more
normally separate polypeptides. Produced from a recombinant
gene.
∆G Change in the free energy during a reaction: the free
energy of the product molecules minus the free energy of the
starting molecules. A large negative value of ∆G indicates that
the reaction has a strong tendency to occur. (Panel 2–7,
pp. 102–103)
G 0 State of withdrawal from the eukaroytic cell-division cycle
by entry into a quiescent digression from the G 1 phase. A
common, sometimes permanent, state for differentiated cells.
G 1 phase Gap 1 phase of the eukaryotic cell-division cycle,
between the end of mitosis and the start of DNA synthesis.
(Figure 17–4)
G 1 -Cdk Cyclin–Cdk complex formed in vertebrate cells by
a G 1 -cyclin and the corresponding cyclin-dependent kinase
(Cdk). (Table 17–1, p. 969)
G 1 -cyclin Cyclin present in the G 1 phase of the eukaryotic cell
cycle. Forms complexes with Cdks that help govern the activity
of the G 1 /S-cyclins, which control progression to S phase.
G 1 /S-Cdk Cyclin–Cdk complex formed in vertebrate cells by
a G 1 /S-cyclin and the corresponding cyclin-dependent kinase
(Cdk). (Figure 17–11 and Table 17–1, p. 969)
G 1 /S-cyclin Cyclin that activates Cdks in late G 1 of the
eukaryotic cell cycle and thereby helps trigger progression
through Start, resulting in a commitment to cell-cycle entry. Its
level falls at the start of S phase. (Figure 17–11)
G 2 phase Gap 2 phase of the eukaryotic cell-division cycle,
between the end of DNA synthesis and the beginning of
mitosis. (Figure 17–4)
G 2 /M transition Point in the eukaryotic cell cycle at which the
cell checks for completion of DNA replication before triggering
the early mitotic events that lead to chromosome alignment on
the spindle. (Figure 17–9)
ganglioside Any glycolipid having one or more sialic acid
residues in its structure. Found in the plasma membrane of
eukaryotic cells and especially abundant in nerve cells.
(Figure 10–16)
gap gene In Drosophila development, a gene that is
expressed in specific broad regions along the anteroposterior
axis of the early embryo, and which helps designate the main
divisions of the insect body. (Figure 21–20)
gap junction Communicating channel-forming cell–cell
junction present in most animal tissues that allows ions and
small molecules to pass from the cytoplasm of one cell to the
cytoplasm of the next.
gastrulation Important stage in animal embryogenesis
during which the embryo is transformed from a ball of cells to a
structure with a gut (a gastrula).
gated transport Movement of proteins between the cytosol
and the nucleus through nuclear pore complexes in the nuclear
envelope that function as selective gates.
geminin Protein that prevents the formation of new
prereplicative complexes during S phase and mitosis, thus
ensuring that the chromosomes are replicated only once in
each cell cycle.
gene Region of DNA that is transcribed as a single unit and
carries information for a discrete hereditary characteristic,
usually corresponding to (1) a single protein (or set of related
proteins generated by variant post-transcriptional processing),
or (2) a single RNA (or set of closely related RNAs).
gene control region The set of linked DNA sequences
regulating expression of a particular gene. Includes promoter
and cis-regulatory sequences required to initiate transcription of
the gene and control the rate of transcription. (Figure 7–17)
gene conversion Process by which DNA sequence
information can be transferred from one DNA helix (which
remains unchanged) to another DNA helix whose sequence is
altered. It often accompanies general recombination events.
(Figure 5–59)
gene family The set of genes in an organism related in DNA
sequence due to their derivation from the same ancestor.
gene segments In immunology: short DNA sequences that
are joined together during B cell and T cell development to
produce the coding sequences for immunoglobulins and T cell
receptors, respectively. (Figure 24–28)
general transcription factor Any of the proteins whose
assembly at all promoters of a given type is required for the
binding and activation of RNA polymerase and the initiation of
transcription. (Table 6–3, p. 311)
genetic code The set of rules specifying the correspondence
between nucleotide triplets (codons) in DNA or RNA and amino
acids in proteins. (Figure 6–48)
genetic instability Abnormally increased spontaneous
mutation rate, such as occurs in cancer cells.
genetic screen Procedure for discovery of genes affecting a
specific phenotype by surveying large numbers of mutagenized
individuals.
genetics The study of the genes of an organism on the basis
of heredity and variation.
genome The totality of genetic information belonging to a
cell or an organism; in particular, the DNA that carries this
information.
genome annotation Process attempting to mark out all
the genes (protein-coding and noncoding) in a genome and
ascribing functions to each.
genomic imprinting Phenomenon in which a gene is either
expressed or not expressed in the offspring depending on
which parent it is inherited from. (Figure 7–49)
genomic library Collection of cloned DNA molecules
representing an entire genome.
genotype Genetic constitution of an individual cell or
organism. The particular combination of alleles found in a
specific individual. (Panel 8–2, p. 486)