Test Questions Flashcards
RNA Splicing
snRNPs bind to start on intron, snRNPs assemble to form the spliceosome, Intron is cut-loop forms, Intron is released as a lariat; exons are joined together.
snRNP
small nuclear ribonucleoproteins – pronounced “snurps”
Genetic Code is: (5 answers)
Redundant, unambiguous, non-overlapping, nearly universal, and conservative.
Mutation categories (3 answers)
Beneficial, Neutral, and Deleterious.
Point Mutation
A mutation that results in a change in a single base pair in DNA.
Point Mutations - Silent
Def - change in nucleotide sequence that does not change the amino acid specified by codon – Con - No change in phenotype; neutral with respect to fitness.
Point Mutations - Missense
Def - Change in nucleotide sequence that changes the amino acid specified by codon – Con - Change in primary structure of protein; may be beneficial, neutral, or deleterious.
Point Mutations - Nonsense
Def - Change in nucelotide sequence that results in an early stop codon – Con - Leads to mRNA breakdown or a shortened polypeptide; usually deleterious.
Point Mutations - Frameshift
Def - Addition or deletion of a nucleotide – Con - Reading frame is shifted, altering the meaning of all subsequent codons; almost always deleterious.
Gene
A section of DNA that encodes information for building one or more related polypeptides or functional RNA molecules.
Gene Expression
The set of processes, including transcription and translation, that convert information in DNA into a product of a gene, most commonly a protein.
Genotype
All the alleles of every gene present in a given individual.
Phenotype
The detectable traits of an individual.
DNA - Primary Structure
Sequence of deoxyribonucleotides; bases are A, T, G, C.
DNA - Secondary Structure
Two antiparallel strands twist into a double helix, stabilized by hydrogen bonding between complementary bases (A-T, G-C) and hydrophobic interactions.
