2. The Organelles Flashcards
What is the primary feature that distinguishes prokaryotic from eukaryotic cells?
presence of a nucleus
What does the nucleus contain?
genome
What is the nuclear envelope?
two lipid bilayers that separates the contents of the nucleus into distinct compartments and isolates the nucleus from other organelles and the cytoplasm
In eukaryotes, what processes occur in the nucleus?
replication
transcription
splicing
What is a chromosome?
separate linear DNA molecule
What is the purpose of the centromere?
ensure newly replicated chromosomes are sorted properly during cell division
What is heterchromatin?
regions of chromosome that are folded into densely packed chromatin
What is euchromatin?
regions of chromosome that are loosely packed
What is the nuclear matrix/scaffold?
structure that provides support and regulates gene expression
What is the nucleolus?
region within the nucleus which functions as a ribosome factory
What is contained in the nucleolus?
loops of DNA
RNA polymerases
rRNA
protein components of the ribosome
What is the function of nuclear pores?
allow passage of material into and out of the nucleus
What is the nuclear localization sequence?
sequence of basic amino acids that allow larger molecules to pass through the nuclear envelope to the nuclear interior
Where does oxidative phosphorylation occur?
mitochondria
What is the matrix of the mitochondria?
interior of the mitochondria that is bound by the inner and outer mitochondrial membranes