Biochemistry Flashcards
How do AGE affect neurons in diabetic patients?
Glucan ion damages myelin in nerves as well as collagen and is usually noticed in long nerves and progresses distal –> proximal in the limb.
How does micro vascular damage occur in patients with diabetes mellitus type II?
Micro vascular damage takes years to develop and is the result of inflammatory and ROS damage to vessels usually in the distal limbs. AGE binds to RAGE receptors and begin a pro inflammatory process. RAGE involves ROS signaling which interfered with NOS signaling which is used in vasodilation of vessels. Additionally glucagon of collagen affects blood vessel structure.
Complete the sentence: diabetic neuropathy is the most common cause of _____, _______, and __________.
What percentage of diabetics will develop neuropathy?
No traumatic limb amputation
End stage renal failure
Blindness
60%
How does diabetic neuropathy present?
Feet may feel cold or have tingling or burning sensation at night
Limb weakness and unsteady walking
Lack of sensation leads to lesions on the feet that may go unnoticed
Insulin regulates which GLUT transporter?
Insulin signal cells to uptake glucose but also signal a decrease in another hormone; name this hormone.
What can inhibit and stimulate insulin release?
Pancreatic beta cells have which GLUT transporter?
GLUT 4 Glucagon Inhibited by epinephrine Stimulated by AA and glucose at high levels GLUT 2 which has a high km value
When insulin stimulates a GLUT 4 transporter what happens next? What happens to the Vmax if the receptors levels expressed are doubled as a result?
When insulin binds to its receptor (tyrosine kinase) intracellular vesicles containing GLUT 4 are expressed on the cell surface.
The km value will be constant during this process but the Vmax will increase with the receptors expression. Double the expression will double Vmax.
Which form of glucose will glycate AA etc? How is glycation different from glycosylation?
Reactive aldehyde or the linear form of glucose.
Glycation is a random chemical reaction that links glucose to protein, whereas glycosylation is enzymatically controlled
What is the Maillard reaction? How does the reaction of glycation progress to the formation of AGE.
Aka the brown reaction (brown mallard) begins with glycation and can be thought of as a AA, DNA, or lipid linking to glucose.
Following glycation, an amadori product is formed (fructosamine) which is a linear fructose molecule bound to a protein. This is then converted to an AGE.
How does the aging process affect AGE in the body?
Increase amadori products
Bio molecule replacement is reduced
ROS is in a positive feedback cycle with AGE which will increase inflammation, and damage to the neurons and microvasulature of the body
Dopamine is classified as what type of neurotransmitter; why?
What’s the enzyme that converts dopamine to norepinephrine?
Monoamine neurotransmitter because it has a single amine group followed by two carbons and a ring.
Dopamine is converted to norepinephrine by the enzyme- dopamine hydroxylase-because it adds a hydroxyl group to the substrate dopamine.
During long term potentiation the post synaptic neuron will increase the number of receptors at its surface. What does this tell you about MOA activity in the presynaptic neuron?
A) it’s more active
B) it’s less active
C) it’s not active
D) it’s reactive
B- if your post synaptic neuron is increasing receptors it’s because more neurotransmitter is present in the synapse. This would be facilitated by a decrease in the degradation neurotransmitter by MOA.
A neurotransmitter that is not readily degraded because of the energy cost associated with its creation is likely to have what effect on the body?
A) transient
B) long term
C) short term
D) systemic
B long term. This gets to the idea that these type of neurotransmitters are likely working via metabotrophic receptors which have longer lasting effects.
What transporter takes hydrophobic amino acids through the BBB? How might the type of AA transported change frequently?
Large neutral AA transporter or LAAT
Diet will largely determine which neurotransmitters are transported, although it does have a low km value for phenylalanine.
Phenylalanine and tryptophan are _______ kinds of amino acids
A) essential
B) non essential
C) hydrophobic and non essential
D) hydrophilic and essential
A essential, and they happen to be hydrophobic also
What happens to phenylalanine in PKU?
A
