Block 5 Flashcards
the endoplasmic reticulum is continuous with what structure
nuclear membrane
where is the site of protein and lipid synthesis
endoplasmic reticulum
what do ribosomes synthesize
proteins
what is the difference between what free and membrane bound ribosomes produce
free produce proteins mostly used by the cell
membrane bound produce proteins for secretion (ex: hormones, digestive enzymes)
where is the site of initiation of posttranslational modification of newly synthesized proteins
rough ER
where does lipid and steroid synthesis occur
smooth ER
where does cholesterol and lipoprotein synthesis occur
smooth ER
where does detoxification of drugs and toxins occur
smooth ER
what is the sarcoplasmic reticulum
smooth ER of muscle cells
what is the function of the sarcoplasmic reticulum
store calcium for muscle contraction
where is the location of glucose 6-phosphatase
smooth ER
what 3 enzymes of steroid synthesis are present in the mitochondria
cholesterol desmolase
17 alpha
11 beta
what enzyme of steroid synthesis is present in the smooth ER
21 beta
what is the rough ER of neurons called
nissl body
what is the function of nissl bodies
synthesize neurotransmitters
what is the main organelle involved in posttranslational modification
golgi
vesicles come in from the __ and leave from the __ golgi
(cis or trans)
enter through cis
leave through trans
what are 3 examples of posttranslational modification
glycosylation
hydroxylation (ex: collagen)
carboxylation (ex: vit K)
what are the 3 main functions of golgi modification
protect proteins from degradation
direct proteins to their target locations
allow protein recognition by receptors
do golgi modifications add N or O oligosaccharides
O
(“O” in the gOlgi)
where does mannose 6-phosphate get added to lysosomal proteins
golgi
N linked oligosaccharides are often attached to what amino acid
asparagine
where are N linked oligosaccharides synthesized
eNdoplasmic reticulum
where are O lined oligosaccharides synthesized
gOlgi
O linked oligosaccharides are often attached to what amino acid
serine or threonine
what is an example of O linked oligosaccharide
mucins
respiratory infection can cause mucin buildup. what can we say about the posttranslational modification which has occurred to produce the mucin
O linked glycosylation in the golgi
is mannose 6 phosphate added to N or O linked oligosaccharides
N
mannose 6 phosphate triggers packaging in trans golgi –> __
lysosomes
defective mannose 6 phosphate addition in the lysosomes can lead to what disease
I cell
what type of inheritance pattern is I cell disease
autosomeal recessive
what enzyme is deficient in I cell disease
N-acetylglucosaminyl-1-phosphotransferase
in I cell disease, since enzymes are not destined properly to the lysosomes, where do they end up
outside the cell
what is missing from the golgi as a result of I cell disease
hydrolases
for enzymes destined to the lysosomes, mannose is added in what organelle
phosphotransferase adds phosphate to the 6th position in what organelle
mannose= ER
6P= golgi
what is the defective enzyme of pompe’s disease
lysosomal alpha 1,4 glucosidase (acid maltase)
what are the symptoms of pompe’s disease
infant cardiomegaly and hypotonia
what type of inheritance is hurler syndrome
autosomal recessive
what type of inheritance is hunter syndrome
X linked
what type of inheritance are sanfilippo and sly syndrome
autosomal recessive
what enzyme is deficient in hunter syndrome
iduronate sulfatase
how can you differentiate hunter syndrome from hurler syndrome
hunter- no corneal clouding
hurler- corneal clouding
what enzyme is deficient in hurler syndrome
alpha L iduronidase
what is the enzyme missing in tay sachs
hexaminidase A
what buildsup in tay sachs
GM2
what are the 2 main symptoms of tay sachs
cherry red spot in macula
startle reflex
what enzyme is missing in gaucher disease
glucocerebrosidase
what builds up as a result of gaucher disease
glucocerebroside
what are the 2 main symptoms of gaucher disease
crumpled paper inclusions
erosion of bones/fractures
what enzyme is missing in niemann pick diease
sphingomyelinase
what builds up as a result of niemann pick disease
sphingomyelin
what are the 2 main symptoms of niemann pick disease
hepatosplenomegaly
foamy macrophages
what builds up in fabry disease
ceramide trihexoside
what enzyme is missing in fabrys disease
alpha galactosidase A
what inheritance pattern is fabrys disease
X linked recessive
what is the main symptom of fabrys disease
peripheral neuropathy
what enzyme is deficient in von gierkes
glucose 6 phosphatase
what enzyme is deficient in cori disease
alpha 1,6 glucosidase (glycogen debranching enzyme)
what enzyme is deficient in mcardles disease
glycogen phosphorylase
von gierkes is evident at what age
6-9m with spaced out feeding
what is the main symptom of cori disease
accumulation of branched glycogen (limit dextrans)
what are the main symptoms of mcardles
decreased plasma lactate
muscle aches and cramping
myoglobinuria after exercise
increased creatinine and aldolase
what are 2 examples of receptor mediated endocytosis
LDL
transferrin
where does transcription occur
where does translation occur
transcription- nucleus
translation- cytosol
a signal sequence directs proteins from __ to __
ribosomes
ER
where in the protein is the signal sequence found
N terminal
signal recognition particles move proteins from __ to __
cytosol to ER
what type of molecules are signal sequences
ribonucleoproteins
CFTR biosynthesis starts with it’s co-translational insertion into the membrane of what organelle
ER
efficacy of CFTR trafficking is controlled by what organelle
ER
where is the site of misfolded CFTR degradation
ER
how are misfolded CFTR proteins degraded
ubiquitination
where is the site of CFTR glycosylation
golgi
the CFTR is what type of channel
chloride ligand gated
what process regulates the CFTR channel
phosphorylation
when there is impaired chloride secretion in those with cystic fibrosis, this leads to what symptom
think mucous
how can you test for cystic fibrosis
sweat test
what chromosome is the CFTR gene found on
7
coated vesicles are important for what type of pathways
secretory
what type of vesicles are used for receptor mediated endocytosis
clathrin coated
what are 3 examples of receptors found in clathrin coated pits
LDL
growth factor
transferrin
COP I is used for __
COP II is used for __
I= retrograde (golgi to ER)
II= anterograde (ER to golgi)
what 4 processes occur in the mitochondria
beta oxidation
TCA cycle
ETC
ketogenesis
what 4 processes occur in the cytosol
fatty acid synthesis
glycolysis
pentose phosphate pathway
glycogenesis
what 3 processes take place in both the cytosol and mitochondria
heme synthesis
urea synthesis
gluconeogenesis
the urea cycle occurs in what part of the mitochondria
mitochondrial matrix
what 3 processes occur in the nucleus
DNA replication
transcription
ribosome assembly
where is the site of rRNA transcription and processing of ribosome assembly
nucleolus
what is the function of proteosomes
destroy misshaped and misfolded proteins
proteasomes have a role in what neurological diseases
parkinsons
what organelle contains oxidative enzymes such as catalase
peroxisomes
what are the 2 main functions of catalase
oxidize H2O2
metabolize ethanol
what fatty acids undergo alpha oxidation
long chain
very long chain
branched chain
what causes refsum disease
defect in peroxisomal alpha oxidation
what causes zellweger syndrome
defective peroxisome synthesis
what causes X linked adrenoleukodystrophy
mutation in the ATP binding cassette leading to defective transport of very long chain fatty acids into peroxisomes
