Definitions Flashcards
Steady State
Requiring energy, does not change with time
Equilibrium
No net energy, no energy transfer
Redundancy
one mechanism fails then others can still maintain that parameter around set point- back up
Hierarchy of importance
set-point of some variables may be altered in order to maintain others
Deficient Homeostatic mechanisms
disease progresses then normal compensatory responses fail and the normal negative feedback mechanism are overtaken by positive feedback loops with disastrous consequence
Negative Feedback
minimized or reversed to keep parameter at a set point
Postive Feedback
Amplification- child birth, ejaculations, ovulation, blood clot formation
Feed-Forward
Anticipation
Osmolarity
total concentration of all particles in solution
Tonicity
concentration of only the osmotically active particles
Imprinting
Methylation of specific loci & silencing of gene
Antiicipation
Individuals in recent generations of a pedigree develop disease at an earlier ages & with greater severity
Digenic disorder
2 mutant loci work together to produce an effect which is not seen without the other
Haplo-insufficiency
half normal levels of the gene product result in phenotypic effects
Gain of function mutation
increased levels of gene expression or the development of a new function of the gene product
Pleiotropy
affects multiple organ systems
Dominant-negative
mutant gene product interferes w/ the function of the normal gene product
Heteroplasmy
ONLY IN MITOCHONDRIAL DISORDERS; variable expression in mitochondria, unequal distributions- severity of disorder depends on the # of mitochondria that have the mutant gene
Necrosis
cell swelling, loss of plasma membrane integrity, inflammation
Apoptosis
Programmed cell death, cell shrinking, maintains plasma membrane integrity, no inflammation
Single Copy Genes
unique sequences in the genome that code for a protein
Multigene Families
genes with similar functions that have risen by gene duplication
Classic Gene families
multi-copy genes that show a high degree of homology
Gene Superfamilies
multi-copy genes with similar function but limited gene homology
SNP
single nucleotide polymorphism; single base pair change between individuals
SSR
simple sequence repeat; tandem repeats of 2, 3, 4 base pairs repeated many times
VNTR
variable number tandem repeats; tandem repeats of 5, 10, 100s of base pairs repeated many times
LCR
Low copy repeat tandem repeats of thousands to hundreds of thousands of base pairs repeated a few times; may cause miss-pairing during mitosis and meiosis
LINE
long interspersed nuclear element; encodes reverse transcriptase that makes DNA from mRNA enabling LINEs to copy themselves and enlarge the genome; may cause miss-pairing during mitosis and meiosis
Pseudogene
sequences that look like real genes but are not function-no protein product
Conventional pseudogne
not expressed and they often occur in gene families; others can be transcribed, but their transcripts are not functional
X-inactivation center
XIST mRNA coat one of the X-chromosomes, that results in transcriptional interference
Loss of heterozygosity
occurs when the inheritance of one disease allele in the germ-line occurs, and then loss of the second functional copy occurs, either during fetal development, or following birth sometime during the lifetime of the individual
Pseudoautomsomal Dominance
an autosomal recessive condition presents in individuals in two or more generations of a family, thereby appearing to follow a dominant inheritance patter
Assortative Mating
occurs when people associate the marry with “likely” -marrying hearing impaired
Loss of Function Mutation
cause either reduced activity (hypomorph) or complete loss of gene product (null allele or apomorph)
Compound Heterozygosit
2 different alleles in an individual
Penetrance
proportion of individuals in a population that carry both the disease genotype and the disease phenotype
Variable Expressivity
the degree in which a genotype is phenotypically expressed
Allelic Heterogeneity
different mutations at the same locus cause the same disease phenotype
Locus Heterogeneity
mutations at different loci that cause the same disease phenotype
New Mutation
de novo mutation caused by increased paternal age mutation hot spots
Germline Mosaicism
occurs when an individual has both normals gametes and diseased gametes
Proteasome
covalently tags proteins targeted for destruction with ubiquitin
