FTM 1 Week 1 Flashcards
What are the 3 major classes of membrane lipids?
phospholipids, cholesterol and glycolipids
What are the 2 major classes of membrane proteins?
Integral membrane and peripheral membrane
What is the most abundant membrane lipid
phospholipids
Where is cholesterol located in membrane lipids and what does it do
intercalates between phospholipids and affects membrane fluidity in temperature dependent manner
What anchors integral membrane proteins
alpha helix, lipid chain, oligosaccharide linker
What kind of bond does peripheral membrane proteins use
noncovalent
What are the integral membrane proteins?
Pumps/carriers and transporters Channels (aquaporins and gap junctions) Receptors Linkers Enzymes Structural proteins
What is the glycocalyx composed of and what does it do?
Composed of: carbohydrate rich zone on cell surface (glycolipids, glycoproteins and proteoglycans)
Helps establish microenvironment at cell surface
What is it called when a substance exits the cell by fusion of a vesicle with the plasma membrane
exocytosis
What is it called when substance enters the cell by a vesicle formed from the plasma membrane
endocytosis
What are the 3 types of endocytosis
- Receptor mediated
- Pinocytosis
- Phagocytosis
What types of endocytosis are clathrin dependent
Clathrin dependent= receptor mediated
What types of endocytosis are Clathrin Independent
Pinocytosis and phagocytosis
What type of endocytosis is actin dependent
phagocytosis
What are the examples of receptor recycled ligand degraded receptor mediated endocytosis
- low density lipoprotein receptor
- insulin glucose transporter receptor
- other peptide hormones and their receptors
What are the examples of receptor and ligand recycled receptor mediated endocytosis
- iron, transferrin and transferrin receptor
- major histocompatibility complex I and II
What are the examples of receptor ligand degraded receptor mediated endocytosis
-epidermal growth factor and receptor
What are the examples of receptor and ligand transcytosis receptor mediated endocytosis
- secretion of immunoglobulin (secretory IgA) into saliva
- secretion of maternal IgG into milk
What are membrane enclosed structure associated with the endocytotic pathway
endosomes
What matures into the lysosome
late endosomes
What is an example of lysosomal storage disease
Tay Sachs Disease
What is the deficiency in Tay Sachs and what does it result in
Deficiency of HEXA
Results in the accumulation of GM2 ganglioside
What are the 5 lysosomal storage diseases
Hurler syndrome (MPS1) Pompe Tay-Sachs Gaucher I-cell disease
What is the faulty enzyme, accumulating product and main organ affected with Hurler syndrome (MPS1)
Faulty enzyme = alpha-L-iduronidase
Accumulating product = dermatan sulphate
Main organ = skeleton and nervous system
What is the faulty enzyme, accumulating product and main organ affected with Pompe
Faulty enzyme = alpha-1,4-Glucosidase
Accumulating product = Glycogen
Main organ = skeleton and nervous system
What is the faulty enzyme, accumulating product and main organ affected with Tay-Sachs
Faulty enzyme = B-hexosaminidase
Accumulating product = GM2 ganglioside
Main organ = Nervous system
What is the faulty enzyme, accumulating product and main organ affected with Gaucher
Faulty enzyme = Glucocerebrosidase
Accumulating product = glucosylceramide
Main organ = Liver and spleen
What is the faulty enzyme, accumulating product and main organ affected with I-Cell disease
Faulty enzyme = Phosphotransferase of M6P formation
Accumulating product = Lysosomal hydrolyses are absent
Main organ = Skeletal and nervous system
What are the pathways to lysosomal digestion
- Phagocytosis
- Endocytosis
- Autophagy
What lysosomal digestion pathway has a clinical correlation to essential role in starvation, cellular differentiation, cell death and cell aging
Autophagy
What structure of a cell has lamin A mutation in Hutchinson-Gilford Progeria syndrome and other laminopathies
nuclear lamina
What structure in a cell allows transport of molecules between the nucleus and cytoplasm
Nuclear Pore complex (NPC)
What is the site for ribosome production
nucleolus
What is less condensed chromatin, more transcriptionally active and light staining
euchromatin
What is dense staining, highly condensed chromatin and less transcriptionally active
heterochromatin
What is the fundamental structural unit of chromatin
nucleosome
What has centric heterochromatin, persists throughout interphase, constricted region that holds sister chromatids together and also the site of kinetochore formation
centromere
What is at the end of chromosomes, repeated sequences that allow the ends of the chromosome to be replicated
telomere
What has telomerase enzyme and cancer and aging
telomere
What is the location where DNA replication begins
replication origin
What has functions in synthesis of lipids and detoxification
Smooth ER
What has functions in synthesis of proteins destined for plasma membrane and lysosomes or secretion
rough ER
What is the abundant cells specialized in protein synthesis, secretory cells producing proteins for extracellular export
RER
What has initial post translational modifications and folding sites
RER
What has ER stress and unfolded protein response in clinical correlation
RER
What has abundant cells specialized in lipid metabolism
smooth ER
What has well developed in cells that synthesize and secrete steroids
SER
What plays a major role in detoxification (cytochrome P450)
SER
What functions to sequester calcium
SER
In the golgi apparatus what type of secretory cells secrete digestive enzymes
pancreatic acinar cells
In the golgi apparatus what type of secretory cells secrete antibodies
plasma cells
What are the two mediated bidirectional traffic between the ER and the golgi
COP-I and COP-II
What is retrograde transport from CGN back to rER
COP-I
What is anterograde transport, carry newly synthesized proteins from rER to CGN
COP-II
What are the functions of golgi
- post translational modification
- Sorting
- packaging
What are the post translational modification substances in the golgi
- glycosylation
- sulfation
- phosphorylation
- proteolysis
What are the types of vesicular trafficking
- Constitutive secretory pathway
- regulated secretory pathway
- lysosomal pathway
What are the digestive organelles that function in the controlled intracellular digestion of macromolecules
lysosomes
What has 2 membranes and 2 compartments, primary function is to generate ATP (TCA, Ox phos, B-oxidation)
mitochondria
What are the mitochondrial diseases
MERRF and leber hereditary optic neuropathy
What plays an important role in fat metabolism, abundant class of phospholipids in myelin, free ribosomes.
Peroxisomes
What is an example of peroxisomal disease
Zellweger syndrome
What is specialized to compartmentalize and degrade toxic reactive oxygen molecules, contains catalase and others, detoxification of ingested alcohol
peroxisomes
