Term
| What is intracellular signaling |
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Definition
| Signals arise within the cell due to allosteric regulation and substrate concentrations |
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Term
| What is intercellular signaling |
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Definition
| Signaling between differs cells, coordinate developmental and survival activities |
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Term
| What are the types of intercellular signaling |
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Definition
| Direct contact, synaptic signaling, endocrine signaling |
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Term
| What occurs during direct contact signaling |
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Definition
| Signals sent between layers of cells at periphery of tissues via gap junctions |
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Term
| When is direct contact signaling used |
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Definition
| Wen cells are not in good contact with vessels |
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Term
| What does direct contact signaling share with the other cells |
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Definition
| mRNA, cell cycle regulators, evidence of pathogen invasion, etc |
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Term
| What occurs in synaptic signaling |
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Definition
| Signaling is carried out using neurotransmitters |
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Term
| What occurs in endocrine signaling |
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Definition
| Hormone is released in one location and travels to a receptor in another location |
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Term
| War is the function of endocrine signaling |
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Definition
| Coordinate multiple tissues, regulate and coordinate metabolism |
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Term
| I general, what is a g-protein coupled receptor classified as |
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Definition
| Integral membrane protein |
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Term
| What is a g-protein coupled receptor specific |
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Definition
| Because it can only interact with one ligand |
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Term
| How is a g-protein coupled receptor structured? How many units does it have? |
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Definition
| It has 7 transmembrane domains |
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Term
| What does it mean when said that a g-protein is heterochromatic |
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Definition
| It has 3 subunits: alpha, beta, gamma |
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Term
| Wen is the G protein alpha subunit located when it is inactive |
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Definition
| At the beta gamma subunit docking station |
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Term
| How can G protein be stimulatory or inhibitory? |
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Definition
| It can interact with the G protein coupled receptor to inhibit the process (Gi) or it can interact with the adenylyl cyclase to stimulate the process (Gs) |
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Term
| When the Alpha subunit binds adenylyl cyclase, where does it bind |
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Definition
| On the guanosine nucleotide |
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Term
| What qualifies the alpha subunit of the G protein to be stimulator or inhibitor |
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Definition
| If it is working with a stimulating G protein it is stimulating (Gas) when working with a inhibiting G protein it is and inhibitor (Gai) |
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Term
| Once protein kinase A is activated, how does it actually effect the cell |
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Definition
| It phosphorlyates target proteins which regulates flow of ions across membranes, regulates metabolic pathways using enzymes, acts as DNA binding protein and promotes or inhibits gene expression |
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Term
| What are the steps in the first path we learned to initiate cellular response to intercellular signals |
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Definition
1. Ligand binds G protein coupled receptor
2. Receptor changes conformation on its inner cellular surface
3. G protein that is interacting with the receptor changes conformation
4. G protein changes GDP to GTP
5. G protein alpha subunit dissociates from the beta gamma dock
6. Alpha subunit changes conformation of adenylyl cyclase
7. Adenylyl cyclase generates cAMP using free ATP
8. cAMP activates protein kinase A by binding to its 2 regulatory subunits and release the two catalytic subunits
9. Protein kinase A phosphorlyates target proteins
10. Alpha subunit hydrolysis GTP to GDP
11. Alpha subunit dissociates from adenylyl cyclase
12. Alpha subunit docks with beta gamma dock |
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Term
| In general, what is a adenylyl cyclase considered to be |
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Definition
| An integral membrane enzyme |
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Term
| In general, what is cAMP considered to be |
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Definition
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Term
| When a ligand binds a G protein coupled receptor, what changes occur in the G protein |
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Definition
| It changes conformation changing GDP to GTP, the alpha subunit dissociates from the beta gamma subunit dock and goes off to find adenylyl cyclase |
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Term
| What tools do adenylyl cyclase need to generate cAMP |
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Definition
| G protein alpha subunit, ATP |
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Term
| How does cAMP activate protein kinase a |
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Definition
| It binds to its two regulatory subunits and causes the release of its two catalytic subunits |
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Term
| What hydrolysis GTP back to GDP |
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Definition
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Term
| Way are the three ways to stop the first path of intercellular signaling |
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Definition
| Remove the hormone (or other extra cellular signaling molecule), dephosphorlyate proteins, hydrolysis of cAMP |
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Term
| What do protein phosphatses do |
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Definition
| Hydrological lay cleave phosphate esters and remove effector proteins that are phosphorlyated by protein kinase |
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Term
| What do cAMP phosphodiesterases do |
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Definition
| Hydrolysis of cAMP, cleaves the phosphodiester bond turning it into 5'-AMP which is inactive |
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Term
| Wy is removing the extra cellular signaling molecule not the most effective way of stopping a intercellular signaling chain |
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Definition
| The effect can still keep going inside the cell |
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Term
| Explain the process of cholerae infection |
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Definition
1. It enters the gut and releases cholera toxin
2. Toxin enters the epithelium and is endocytosed, only the elephant subunit enters the cell
3. Alpha subunit is clipped
4. Alpha subunit interacts with ADP ribosylation factor
5. The factor activates adenylyl cyclase permanently
6. Lots of cAMP is made so lots of protein kinase is made
7. Ca is released from the ER opening Cl channels
8. Cl drags positive ions (Na) and water out of the cell into large intestines
9. This much water cannot be absorbed so it causes dirreaha and denydration |
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Term
| How is a cholerae infection treated |
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Definition
| Water and electrolytes to replace the water lost, there isn't a problem absorbing the water just retaining it |
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Term
| What causes the build up of water in the intestines in a cholerae infection |
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Definition
| Ca release opens Cl channels and drags after and positive ions and water into the large intestines |
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Term
| What are the steps in the second path we learned to initiate cellular response to intercellular signals |
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Definition
1. Ligand binds receptor
2. Receptor conformation changes activates Gq protein
3. Gq protein releases GDP and binds GTP
4. Gaq subunit detaches and activates phospholipid C
5. Phospholipid c cleaves the lipid bi layer into IP2, IP3, DAG
6. IP3 binds ER activating Ca channels releasing Ca into cytosol
7. DAG stays in the membrane, activating protein kinase C with the help of Ca
8. Ca and protein kinase C work together as a secondary messenger to turn on phosphorylation proteins |
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Term
| Where is phospholipase C located |
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Definition
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Term
| What does phospholipase C do when activated |
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Definition
| Cleaves the lipid bi layer into IP2, IP3, and DAG |
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Term
| If in the liver and the ligand is epinephrine, what intracellular signaling process is activated, how does it happen |
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Definition
| Glycogen degradation when epinephrine binds a1 adrenic receptor. Calcium binds cal moulin, this new complex changes conformation of enzymes in metabolism |
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Term
| how do organs of metabolism communicate |
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Definition
| nervous system, circulating substrates, hormones |
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Term
| in metabolism, what do hormones signal for |
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Definition
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Term
| what is coordination of the metabolism primairly regulated by |
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Definition
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Term
| what is coordination of the metabolism secondairly regulated by |
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Definition
| epinepherine and norepinepherine |
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Term
| where is insulin produced |
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Definition
| beta cells of the islets of langerhan in the pancreas |
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Term
| what is insulin stored in |
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Definition
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Term
| where is glucagon produced |
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Definition
| alpha cells of the islets of langerhan in the pancreas |
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Term
| what type of effetor is insulin |
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Definition
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Term
| what type of effector is glucagon |
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Definition
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Term
| in general what does insulin affect, what does this cause |
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Definition
| it affects glycogen, TAGs, and proteins. promotes glucose uptake |
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Term
| in general, what does glucagon affect, what does this cause |
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Definition
| affects glucose release from the liver. it causes gluconeogenesis and glycogenolysis |
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Term
| what stimulates insulin to be released |
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Definition
| increased blood glucose, amino acids, peptide hormones, glucagon decreases |
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Term
| what do peptide hormones have to do with insulin |
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Definition
| when produced due to response to food ingestion, they cause insulin to be released |
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Term
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Definition
| decreased amino acids, epinepherine |
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Term
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Definition
| decrease in glucose or amino acids (fasting), increase in epinepherine |
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Term
| what can causes increases in epinepherine in the body |
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Definition
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Term
| what effect does epinepherine have on the body |
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Definition
| increases glucagon, decreases glucose, affects mobilization of glucose from the liver and fatty acids from adipose |
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Term
| in general, what inhibits glucagon |
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Definition
| increasing glucose or insulin levels |
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Term
| what are the types of glucose receptors |
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Definition
| insulin sensitive and insulin insensitive |
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Term
| what type of tissues are insulin insensitive receptors located |
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Definition
| in tissues that require uptake of glucose but do not have a role in blood sugar regulation |
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Term
| what tissues have insulin insensitive receptors and use active transport |
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Definition
| epithelia of intestine, renal tubules, choroid plexus, |
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Term
| what tissues have insulin insensitive receptors and use facilitative transport |
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Definition
| RBC, WBC, lens of eye, cornea, liver, brain |
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Term
| what type of transport do tissues with insulin sensitive receptors use |
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Definition
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Term
| what tissues have insulin sensitive receptors |
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Definition
| most tissues: skeletal muscle, adpipose.. |
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Term
| what is the general cause of hypoglycemia |
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Definition
| low glucose causes elevated glucagon and epinepherine and low insulin |
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Term
| what are the adrenergic symptoms of hypoglycemia |
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Definition
| anxiety, papitation, sweating, tremor |
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Term
| what causes the adrenergic symptoms of hypoglycemia |
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Definition
| epinepherine, ACTH, and growth hormone release from the hypothalamus in response to decreased glucose levels |
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Term
| what are the neuroglycopenia symptoms of hypoglycemia |
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Definition
| headache, confusion, slurred speech, seizures, coma, death |
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Term
| what causes the neuroglycopenia symptoms of hypoglycemia |
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Definition
| impaired delivery of glucose to the brain |
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Term
| what is the treatment of hypoglycemia |
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Definition
| resolved in minutes of glucose intake |
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Term
| what is the main worry of someone who is experiencing hypoglycemia |
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Definition
| CNS only fuel is glucose, without glucose for too long nerves die, could cause death |
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Term
| what does transient hypoglycemia cause |
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Definition
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Term
| what are the types of hypoglycemia |
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Definition
| insulin injected, postparandial, fastine |
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Term
| what type of patients usually have insulin injected hypoglycemia |
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Definition
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Term
| what are symptoms of insulin injected hypoglycemia |
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Definition
| unconsious, no coordiinated swallow reflex |
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Term
| how do you treat insulin injected hypoglycemia |
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Definition
| subcutanous or intramuscular glucagon injection |
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Term
| what is the second most common hypoglycemia |
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Definition
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Term
| what causes postparandial hypoglycemia |
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Definition
| exaggerated insulin release following a meal |
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Term
| how do you treat postparandial hypoglycemia |
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Definition
| auto corrects itself, eat frequent small meals |
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Term
| what is the most rare hypoglycemia |
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Definition
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Term
| what are the most serious symptoms involved in fasting hypoglycemia |
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Definition
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Term
| what causes fasting hypoglycemia |
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Definition
| low liver glucose production, fasting and alcohol, pancreatic tumors that make lots of insulin |
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Term
| what are the three paths you could take to try and inhibit glucagon signaling |
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Definition
| regulate glyconeogenesis, increase glycogen storage, decrease glycogen storage |
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Term
| how can glycogenesis be regulated to stop glucagon signaliing |
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Definition
| dephosphorlyate glycogen synthase |
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Term
| how can glycogen storage be increased to stop glucagon signaliing |
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Definition
| add insulin which decreases cAMP with phosphodiesterase and activates protein phosphatase 1. dephosphorlyate glycogen synthase to activate it |
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Term
| how can glycogen storage be decreased to stop glucagon signaliing |
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Definition
| glycagon and epinepherine induce cAMP production, protein kinase A phosphorlyates glycogen synthase, phosphorlyated glycogen synthase is inactivated |
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Term
| in gulcagon signaling once the associated enzymes are phosphorlyated, what occurs in the liver |
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Definition
| break don of glycogen and increased gluconeogenesis, ketogenesis, amino acid uptake to make carbon skeletons for gluconeogenesis |
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Term
| in gulcagon signaling once the associated enzymes are phosphorlyated, what occurs in the adipose |
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Definition
| activation of lipolysis, free fatty acids are used by the liver to make acetyl coenzyme A to do ketogenesis |
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Term
| what are the steps of glucagon signaliing |
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Definition
1. glucagon binds glucagon receptor
2. receptor activates g-protein which activates adenylyl cyclase
3. adenylyl clcyase generates cAMP
4. protein kinase phosphorlyates and activates metabolic enzymes |
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Term
| what are the steps of insulin signaling |
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Definition
1. insulin binds receptor tyrosine kinase on the insulin receptor
2. tyrosine kinase phosphorlyates beta subunit of insulin receptor and insulin receptor substrates
3. substrates promote activation of protein kinases and phosphatases
4. proteins affect gene expression, cell metabolism, and cell growth |
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Term
| once insulin binds to the membrane, what changes occur in the membrane |
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Definition
| insulin promotes recruitment of insulin sensitive glucose transporters in so more transporters come to the membrane and increase insulin mediated glucose uptake |
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Term
| what changes occur in the membrane after insuliin levels are reduced |
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Definition
| glucose transporters are taken out of the membrane and stored in the cell as endosome |
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Term
| after signaling, what does insulin cause to happen to carbohydrate metabolism (explain what goes on in each tissue) |
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Definition
| glycogen synthesis in the liver, increases glucose transporters in muscle (GLUT-4), in adipose it causes glycerol-3-phosphate synthesis for TAG production |
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Term
| after signaling, what does insulin cause to happen to lipid metabolism |
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Definition
| takes fatty acids out of the blood to increase TG synthesis in adipose, uses glucose to make glycerol-3-phosphage and FA for TAG synthesis |
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Term
| after signaling, what does insulin cause to happen to protein metabolism |
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Definition
| stimulates amino acid uptake by most tissues and protein synthesis |
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Term
| How do beta cells sense changes in glucose levels, explain the process |
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Definition
| Sugar is phosphorlyated by glucokinase and converted to ATP, the increase in ATP closes K channels, depolarizing the membrane, calcium voltage gated ion channels open, calcium flows in, fusion and secretion of insulin granules that are inside the cell |
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