Midterm 1 Flashcards
centromere
the center of a chromosome
q
the long arm of a chromosome
p
the short arm of a chromosome
pyridimine
single carbon base pairs (cytosine and thymine) that pair with purines (adenine and guanine)
purine
double carbon base pairs (adenine and guanine) that pair with single carbon base pairs (cytosine and thymine)
genes
groupings of base pairs that are used to form an end product of a protein to dictate cellular functioning; the recipe to make a certain protein
23,000
the approximate number of genes per nucleus
somatic cells
23 pairs of chromosome
gamete cells
23 single chromosomes (reproductive cells)
2 steps of DNA replication
- transcription 2. translation
transcription
using the DNA template to make a copy called mRNA (U pairs with A instead of T)
translation
a process in which tRNA directs the synthesis of a polypeptide which takes place on the ribosome using rRNA
polymerase
proof reads the mRNA
Redundant DNA/ Desert DNA
sections that are not parts of specific genes and do not code for proteins (95% of DNA)
Point mutations
a mutation that substitutes one base for another
Missense point mutations
a mutation that can cause minor or severe problems
Silent point mutations
a mutation that makes no difference, the resulting codon still codes for the same amino acid
Nonsense point mutations
a mutation that causes an early stop signal resulting truncated or ineffective proteins
Frameshift mutations
replication of a gene starts or ends at a different place
Insertion
adding an extra base, a type of frameshift mutation
Deletion
removal of a base, a type of frameshift mutation
Reading frameshift mutation
A mutation in a DNA chain that occurs when the number of nucleotides inserted or deleted is not a multiple of three, so that every codon beyond the point of insertion or deletion is read incorrectly during translation
translocation
one piece of chromosome “trades” information for another Ex. Chronic Myelogenous Leukemia (CML) and the Philadelphia chromosome
allele
any alternative form of a given gene Ex. eye color trait may be blue or brown
locus
position of a gene on a chromosome
heterozygous
carrying two different allele’s for a gene Ex. Aa
homozygous
carrying 2 copies of the same allele for a gene Ex. AA
Genotype
the genetic code of a person, their unique sequence of DNA
Genome
the complete set of genes in a human
Phenotype
recognizable traits of a particular genotype, outward appearance of a trait Ex. blue eyes
Karyotype
pictorial chromosomal make up of an individual Ex. looking for an extra chromosome in Down’s Syndrome
Expressitivity
the level that a gene is expressed in a phenotype which can be moderate to severe
Penetrance
the ability of a gene to represent itself (penetrate)
Epigenetic
heritable expression of genes, excluding nucleic acids
Mendel’s 1st Law
The Principle of Segregation- when forming gamete cells only one allele goes to each cell
Mendel’s 2nd Law
The Principle of Independent Assortment- the emergence of one trait will not affect the emergence of another Ex. blue eyes doesn’t affect hair color
Autosomal Dominant
a disease in which a person needs only one mutant allele Ex. Huntington’s
Autosomal Recessive
a disease in which a person needs two mutant alleles Ex. Sickle Cell Anemia
X-linked Disorders
such disorders demonstrate a characteristic phenotype in males Ex Hemophilia, Turner’s Syndrome, Klinefelter Syndrome
Complex Multifactorial Diseases and Disorders
Several genes have mutations that individually or together casue a disease Ex. Diabetes type 1, Diabetes type 2
Atrophy
decrease in cell size associated with loss of components and organelles
Physiologic Atrophy
normal atrophy w/ age ex. thymus, sex glands, brain
Pathologic atrophy
atrophy due to disease
Disuse
decreased workload as with bedrest
Denervation
decreased nerve stimulation as with paralysis
Ischemia
decreased blow flow
Ubiquitin-proteosome pathway
normal process of degrading proteins in the cytoplasm to recycle or turnover proteins (ubiquitin is the first protein in the pathway), deregulated with cancer
cachexia
wasting
hypercatabolic
high energy
hypertrophy
increase in cell size (protein and components)
hyperplasia
increase in number of cells (only in cells capable of mitosis)
