Biochem Exam 4: Glycosides & Glycolipids

Front 1

Main functions of glycoside formation

Back 1

-increases solubility
-provides functionality

Front 2

How does the formation of glycosides increase solubility?

Back 2

-DISTRIBUTES endogenous molecules throughout body
-CLEARANCE of "foreign" substances (drugs, toxins) & degradation products of endogenous biomolecule (heme, steroid hormones, etc)

Front 3

How does the formation of glycosides provide functionality?

Back 3

-can be cell RECOGNITION MOLECULES
-can have DIFFERENT EFFECTIVENESS (such as morphin-6-glucuronide)

Front 4

In order to link monosacharides together or attach them to protein or lips, they must be in _________ form

Back 4

nucleotide-activated form

name= UDP-___(monosacharide)___________

Front 5

what enzymes catalyze these linkages?

Back 5

glycosyltransferases
*specific

Front 6

Hydrolysis of UDP linkage provides energy for what?

Back 6

glycosidic bond formation

Front 7

UDP-glucose is a necessary precursor for essential biomolecules, including ______

Back 7

UDP-glucuronate

Front 8

Oxidation of UDP-glucose to UDP-glucuronate is catalyzed by what enzyme?

What cofactor does this enzyme require?

Back 8

UDP-glucose dehydrogenase

requires NAD+ cofactor

Front 9

UDP-glucuronate is used for the synthesis of what (5 things)?

Back 9

1. bilirubin diglucuronide
2. glucuronides
3. UDP-xylose (GAGs)
4. Iduronate (GAGs)
5. Proteoglycans, glycoproteins

Front 10

synthesis of Bilirubin diglucuronide requires what, in addition to UDP-glucuronate?

Back 10

bilirubin

Front 11

synthesis of glucuronides require what, in addition to UDP-glucuronate?

Back 11

-OH
from steroids, drugs, xenobiotics, bilirubin

Front 12

Bilirubin is the degradation product of what?

Back 12

the HEME group of hemoglobin

Front 13

Unconjugated bilirubin has (low/high) solubility

Back 13

low solubility

Front 14

Two glucuronate residues are added to bilirubin to produce what?

Where does this occur?

Back 14

Bilirubin diglucuronide


liver

Front 15

Where is bilirubin diglucuronide excreted?

Back 15

into the bile

Front 16

What is jaundice caused by?

How does it manifest?

Back 16

cause: inability to conjugate/excrete bilirubin, leading to accumulation in blood and entrance into tissues
manifestation: yellow sclera and skin

Front 17

Jaundice occurs frequently in newborns because they have low levels of what enzyme?

Back 17

bilirubin glucuronyltransferase

Front 18

Specific glucuronyltransferses add glucuronate to hormones in the liver, eventually these glucuronides will be excreted mainly in urine & in bile. What are some examples of these hormones?

Back 18

estrogen
progesteron
triiodothyronine
morphine

Front 19

Chronic alcoholic males frequently develop gynomastia due to what?

Back 19

inefficient glucuronidation and clearance of estrogen

Front 20

Morphine is converted into two glucuronide forms, which one is active?

Back 20

Morphine-6-glucuronide
-has longer lasting medicinal effects & fewer side effects than morphine

Front 21

What drug is an antibiotic that inhibits prokaryotic & mitochondrial protein synthesis?

Back 21

Chloramphenicol
* conjugated by glucuronic acid in liver & cleared through kidneys

Front 22

Newborns can have toxic levels of chloramphenicol after treatment because they have low levels of what enzyme, in addition to low clearance of the drug?

Back 22

low levels of glucuronyl transferases

Front 23

What syndrome is caused by the toxic levels of chloramphenicol?
what does it cause?

Back 23

Gray baby syndrome
causes:
-inhibition of mitochondrial fxn
-metabolic acidosis
-cyanosis (ashen color), lethargy, vomiting, irregular respiration

Front 24

23 yr old Greek male suddenly becomes pale, feels fatigued, & has bouts of shortness of breath. When he arrives at hospital he presents w/ yellow eyes, low hemolglobin, & high bilirubin. What is the most likely primary cause of his yellow eyes?

Back 24

excessive destruction of RBCs
^leads to overwhelmed liver

Front 25

Glycolipids include: (4 groups)

Back 25

cerebrosides
sulfasides
globosides
gangliosides

Front 26

all glycolipids consist of what 3 things

Back 26

a sphingosine, a FA chain, a caraboydrate

(sphinosine + FA chain = ceramide)

Front 27

What carbohydrate do the following groups contain:
cerebrosides
sulfasides
globosides
gangliosides

Back 27

cerebrosides- single glucose or galactose
sulfasides- sulfated galactose
globosides- short neutral oligosaccharide
gangliosides- acidic oligosaccharide (contains sialic acid)

Front 28

RBCs can only be transferred if the recepient does not have ANTIBODIES against the donor's blood group ___________.

Back 28

antigens

Front 29

Ceramides can be synthesized from what?
where does there synthesis occur?

Back 29

serine, palmitoyl CoA, fatty acyl CoA

takes place in membrane of ER

Front 30

Sugar addition starts in the _____ and is completed in the ______

Sugars have to be in what form to be added to ceramides?

Back 30

starts in ER
completed in Golgi

nucleotide-activated

Front 31

Where are glycolipids degraded?

Diseases of degradation are called what?

Back 31

lysosomes

sphingolipidoses, lysosomal storage diseas

Front 32

Tay-Sachs disease is caused by the deficiency of what enzyme?
accumulation of what?
and leads to what?

Back 32

beta-hexoaminidase A

GM2 gangliosides

rapid & progressive neurodegeneration, blindness, cherry-red macula, muscular weakness, seizures

Front 33

GM1 Gangliosidosis is caused by the deficiency of what enzyme?
accumulation of what?
and leads to what?

Back 33

beta-galactosidase

GM1 ganglioside & keratan sulfate

neurologic deterioration, hepatosplenomegaly, skeletal deformities, cherry-red macula

Front 34

Sandhoff's disease is caused by the deficiency of what enzyme?
accumulation of what?
and leads to what?

Back 34

beta-hexoaminidase A & B

GM2 gangliosides & globosides

same neurodegenerative symptoms as Tay-Sachs + visceral symptom involvement

Front 35

Fabry disease is caused by the deficiency of what enzyme?
accumulation of what?
and leads to what?

Back 35

alpha-galactosidase

globosides

reddish-purple skin rash, kidney & heart failure, burning pain in lower extremities

Front 36

Gaucher disease is caused by the deficiency of what enzyme?
accumulation of what?
and leads to what?

*most common lysosomal storage disease*

Back 36

glucocerebrosidase

glucocerebrosides

hepatosplenomegaly, osteoporosis of long bones, CNS involvement in rate infantile & juvenile forms

*mainly affects macrophages--> crumpled appearance of cytoplasm caused be enlarges lysosomes filled w/ glucocerebrosides* (staining)

Front 37

Metachromatic leukodystrophy disease is caused by the deficiency of what enzyme?
accumulation of what?
and leads to what?

Back 37

arylsulfatase A

sulfatides

cognitive deterioration, DEMYLINATION, progressive paralysis, dementia in adult form
*
nerves stain yellow-brown w/ cresyl violet (metachromasia)

Front 38

Krabbe disease (globoid cell luekodystrophy) is caused by the deficiency of what enzyme?
accumulation of what?
and leads to what?

Back 38

galactocerebrosidase

galactocerebrosides

mental & motor deterioration, blindness & motor deafness, NEAR-TOTAL LOSS of MYELINATION, globoid bodies (glycolipid-laden macrophages) in white matter of brain

Front 39

Niemann-pick (A + B) disease is caused by the deficiency of what enzyme?
accumulation of what?
and leads to what?

Back 39

sphinomyelinase

sphinomyelin

hepatosplenomegaly, neurodegenerative course (type A)

Front 40

Farber disease is caused by the deficiency of what enzyme?
accumulation of what?
and leads to what?

Back 40

ceraminidase

ceramide

painful & progressive joint deformity, subcutaneous nodules of lipid-laden cells, hoarse cry, tissues show granulomas

Front 41

The common symptom of all lysosomal sphingolipid storage diseases is what?

Specific disease diagnosis is made by measuring what?

Back 41

neurological symptoms

measuring the activity of the appropriate enzymes in leukocytes

Front 42

What process is defective in the following storage diseases?
Pompe disease:
Mucupolysaccaridoses:
Sphingolipidoses:
Mucolipidoses (I-cell):

Back 42

Pompe disease: glycogen degradation
Mucupolysaccaridoses: GAG degradation
Sphingolipidoses: Sphingolipid degradation
Mucolipidoses (I-cell): Targeting of lysosomal enzymes (lack of Man-6-P)

Front 43

5 yr old girl complains of pain in left hip. Testing reveals hepatosplenomegaly, slightly elevated liver enzymes, reduced bone density in left femur, & beta-glucocerebrosidase acitivity in peripheral leukocytes only 10% of normal value. What biochemical pathway is deficient?

Back 43

lysosomal degradation of glycolipids