The Cell Flashcards
cell theory
four basic tenets:
- all living things are composed of cells
- the cell is the basic functional unit of life
- cells arise only from preexisting cells
- cells carry genetic information in the form of deoxyribonucleic acid (DNA); this genetic material is passed on from parent to daughter cell
eukaryotic cells
contain a true nucleus enclosed in a membrane
prokaryotic cells
do not contain a nucleus
lack mitochondria
primitive cytoskeleton
different size of ribosome
organelles
in eukaryotic cells, most are membrane-bound, which allows for compartmentalization of functions
cytosol
allows for the diffusion of molecules throughout the cell
nucleus
within which genetic material encoded in DNA, organized into chromosomes
contains all of the genetic material necessary for replication of cell
surrounded by double membrane that maintains a environment separate and distinct from the cytoplasm
mitosis
how eukaryotic cells reproduce, forming two identical daughter cells
nuclear envelope
double membrane that maintains an environment separate and distinct from the cytoplasm
nuclear pores
in nuclear membrane, allow for selective two-way exchange of material between the cytoplasm and the nucleus
genes
coding regions of DNA
histones
linear DNA wound around these organizing proteins
chromosomes
once linear DNA wound around histones, wound further into these linear strands
nucleolus
subsection of the nucleus where ribosomal RNA (rRNA) is synthesized
only takes about ~25% of volume of entire nucleus
mitochondria
“the power plants of the cell” – reference to important metabolic functions
contain two layers: outer and inner membranes
semi-autonomous
contain some of their own genes and replicate independently of the nucleus via binary fission
thought to have evolved from an anaerobic prokaryote engulfing an aerobic prokaryote and establishing a symbiotic relationship
capable of killing the cell by release of enzymes from the electron transport chain –> kick-starts apoptosis
outer membrane of mitochondria
serves as barrier between cytosol and inner environment
cristae
numerous infolding of the inner membrane, which contains molecules and enzymes necessary for electron transport chain
highly convoluted structures that increase the surface area available for electron transport chain enzymes
intermembrane space
space inside the inner and outer membranes
mitochondrial matrix
space inside the inner membrane
apoptosis
programmed cell death
lysosomes
membrane-bound structures containing hydrolytic enzymes that are capable of breaking down many different substrates, including substances ingested by endocytosis and cellular waste products
autolysis
release of hydrolytic enzymes of the lysosome
results in apoptosis
directly lead to degradation of cellular components
endoplasmic reticulum (ER)
series of interconnected membranes that are actually contiguous with the nuclear envelope
single membrane folded into numerous invaginations, creating complex structures with a central lumen
two varies: smooth and rough
rough ER (RER)
studded with ribosomes
ribosomes
permit the translation of proteins destined for secretion directly into its lumen