Ch 1: Cell as a Unit of Health and Disease Flashcards
what are the two variants of stem cells
totipotent (embryonic) and adult (tissue)
what is a totipotent (embryonic) stem cell
cell that has a limitless cell renewal capacity
can give rise to any type of cell in the body
*think tot as toddler, can grow into anything it wants
what is an adult (tissue) stem cell
cells that have limited lineage potential
can only generate new cells within the same tissue
what are the two important properties of stem cells
self renewal
asymmetric division (one cell for self and one to differentiate and become tissue)
what are the four main purposes of the plasma membrane
selective barrier
detects chemical signals
anchors cell to adjacent structures
fluidity
which substances can cross the phospholipid bilayer
water and other small molecules such as CO2, N2, and O2
which substances cannot cross the phospholipid bilayer
ions
glucose (needs help of carrier protein)
urea (needs help of carrier protein)
what is passive diffusion
ions passively move down their concentration gradient into or out of the cell
what are the two types of fluid-phase uptake
phagocytosis and transcytosis
explain Cholera
vibrio cholerae is ingested and replicates in the GI tract
toxin is released and enters intestinal cell
toxin stimulates adenylyl cyclase pathway
cystic fibrosis conductance regulator (CFTR) opens
chloride ions enter the lumen and water follows
extreme diarrhea
what are the three components of the cytoplasm
cytosol
cytoskeleton
organelles
what are the four functions of the cytoskeleton
maintain and change cell shape
produce cell movements
organize intracellular organelles
maintain polarity
what are the protein subunits of actin filaments
G-actin
what are the protein subunits of microtubules
tubulin
what are microfilaments (actin filaments)
most abundant protein in cells
support and maintain shape of cells
help cells move
ex. thin filaments in skeletal muscles
what are intermediate filaments
made of different proteins that contribute to cell shape and help anchor the nucleus
ex. epithelial cells link to desmosomes
individual filament proteins expressed differently in different cells which can help in identifying tumor origin
what are microtubules
have polarized ends
participate in intracellular transport mechanisms through motor proteins
form centrioles
make up cilia and flagella
which motor protein goes - to +
kinesin
*think Krystina is negative and goes to positive on meds
which motor protein goes + to -
dyneins
what do centrioles do
aid in separation and movement of chromosomes during cellular division
defects in which portion of the cytoskeleton causes neurodegenerative disorders
microtubules
causes Alzheimer’s, Parkinsons, and Amyotrophic lateral Sclerosis
defects in which portion of the cytoskeleton causes giant axonal neuropathy
microfilaments
defects in which portion of the cytoskeleton causes keratinopathies
intermediate filaments
what are keratinopathies
disorders of keratin genes caused by defects in intermediate filaments
causes issues with the hair and skin
what is white sponge nevus
dominant condition caused by a mutation in Keratin 4 or 13 genes
causes irregular intermediate filaments
causes white patches of tissue in the mouth
can lead to bacterial infections
what are some membrane-bound organelles
nucleus, mitochondria, peroxisomes, ER, Golgi, and lysosomes
what are some non membrane-bound organelles
ribosomes and cytoskeleton
which portion of the nucleus makes the most RNA and ribosomes
nucleolus
where does the krebs cycle occur within the mitochondria
inner membrane
where does the electron transport chain occur within the mitochondria
on cristae
which organelle is a major regulator of apoptosis and large generator of reactive oxygen species (ROS)
mitochondria
what is Leber Hereditary Optic Neuropathy
a point mutation (addition, deletion, or change of a single base pair within a genome) within the DNA of the mitochondria
causes visual failure in young adults
what is Kearns-Sayre syndrome
deletion of a segment of the mitochondrial DNA
affects multiple different systems
what is the main purpose of the rough ER
protein synthesis
which cells will have more rough ER
those that make more proteins
ex. myocytes
what is the mechanism of cystic fibrosis
mutation in the cystic fibrosis transmembrane conductance regulator (CFTR)
mutation causes misfolding of the CFTR which is a chloride ion channel
protein gets sent out by the rough ER to be destroyed
leads to deficient chloride ion transport in lungs
what are the four main purposes of smooth ER
lipid and steroid synthesis
stores calcium
glycogen and lipid metabolism
detoxification using cytochrome P-450 enzyme
what does the Golgi apparatus do
processes, packages, secretes, and distributes macromolecules such as proteins and lipids into and out of the cell
secretes by exocytosis and sent to lysosomes to be destroyed
what is achondrogenesis type 1A
recessive disorder where the microtubules of the Golgi apparatus are disturbed
nonsense mutation (early termination) of Trip11 gene which causes loss of GMAP-210 protein
affects cartilage and skeleton
leads to neonatal death
what do lysosomes do
vesicles that contain hydrolytic enzymes to engulf, digest, and release substances into cytoplasm for reuse
involved in apoptosis and immune system via phagolysosome
what is Pompe disease
recessive disease where there is a defect in the alpha glucosidase
leads to excessive glycogen storage
what is Tay-Sachs Disease
recessive disease where there is a defect in the enzyme beta-hexosaminidase A (HEXA gene)
causes accumulation of GM2 gangliosides in the CNS
what do proteasomes do
recognized and degrade misfolded proteins by ubiquitin-proteasome system
what do peroxisomes do
contain oxidative enzymes which neutralize free radicals
what is Adrenoleukodystrophy (X-linked)
defect in a peroxisome membrane transporter which leads to an accumulation of very long chain fatty acids in brain and adrenal cortex
what are some functions of the extracellular matrix
mechanical support
regulator of cell proliferation
bm or stromal scaffolding for tissue removal
foundation for establishment of tissue microenvironments
what are the three things that make up the extracellular matrix
fibrous structural proteins
water-hydrated gels
adhesive glycoproteins
what are fibrous structural proteins
made of collagen and elastins for tensile strength and recoil
what are water-hydrated gels
proteoglycans and hyaluronan that allow for compressive resistance and lubrication
