20 - Lecture No: 1 (Cellular organization) Flashcards
What is a child deficient in if showing Tay-Sachs disease?
HEXA - Beta hexosaminidase A, alpha subunit
What does rER do?
site of initial post-transitional modifications and folding
What is the largest organelle in the cell?
Nucleus - 10% of cell volume
Peroxisomes
Have an important role in fat metabolism
Centomere
region that holds the sister chromatids together, site of kinetochore formation
Are lysosomes acidic or basic?
Acidic - pH 4.7
Coatomer-coated vesicles?
control the traffic flow between the ER and the Golgi
What is the first LSDs characterized?
Tay-Sachs disease - It’s caused by the absence of an enzyme that helps break down fatty substances. These fatty substances, called GM2 gangliosides, build up to toxic levels in the child’s brain and affect the function of the nerve cells
What is lysosomal storage disease? and what is the most common?
inherited metabolic disease resulting in high amounts of toxic materials in the body’s cells as a result of enzyme deficiencies.
Most common: Gaucher Disease - unable to break down lipids(fats) and carbs (sugars)
what is an important factor in the intrinsic apoptosis pathway?
cytochrome c
Outer nuclear membrane
it faces the cytoplasm
Rough ER
synthesis of proteins heading towards the plasma membrane, lysosomes or secretion
What do plasma cells secrete?
Secrete antibodies
What does the outer membrane of the mitochondria contain?
Porins - large channel forming proteins
Enzymes - phosphlipase and acetyl coenzyme a
Where are mitochondria mainly found?
In cells that need to generate large amounts of energy - striated muscle
sER
Has cells for lipid metabolism and cells to secrete steroids, plays a major role in detoxification
Zellweger Syndrome
- Show with Hypotonia (poor muscle tone), skeletal abnormalities, vision loss, hearing loss,
Mutations in genes required for peroxisome function
What is the NPC made up of?
Nucleoporins
Domains of cellular life
Bacteria(Prokaryotic cells)
Archaea(Prokaryotic cells)
Eukaryota(Eukaryotic cells)
What is the faulty enzyme in 1-cell disease and what is buliding up?
Phosphotranseferase and lysosomal hydrolyses and abscent in lysosomes.
What is the faulty enzyme in Pompe and what is building up?
alpha-1.4-glucosidase and gylcogen
Smooth ER
Synthesis of lipids and detoxification
What are the three pathways to lysosomal digestion?
Phagocytosis, Endocytosis, Autophagy
How is chromatin packaged?
Packaged into nucleosomes (complex of DNA and proteins called histones)
G
Initial ribosomal assembly
FC
stains pale, DNA loops of 5 chromosomes (13,14,15,21,22), contains rRNA genes
What is the faulty enzyme in Tay-Sachs and what is building up?
Beta-hexosaminidase and GM2 ganglioside
Telomere
At the ends of the chromosome, has a repeated sequence allowing replication.
Myoclonic epilepsy with ragged red fibers?
Due to mutation in the MT-TK tRNA gene
might show: myopathy (muscle weakness), ataxia (uncoordinated), dementia (slowed intelectual function)
Example of sEr detoxifying?
Cytochrome P450 - these proteins oxidize steroids, fatty acids, and xenobiotics, and are important for the clearance of various compounds, as well as for hormone synthesis and breakdown.