Biochem Lab Quiz 3

What is carbon monoxide gas?

Odorless, colorless, and non-irritant gas, easily diffuses across alveolar membranes, incomplete combustion

Why is CO poisoning a silent biochemical hijacker?

Binds to iron blocking the O2 binding and blocks release of O2

How much higher affinity does CO have than O?

240x

What kind of inhibition takes place during hemoglobin affinity battle?

Competitive

What forms during hemoglobin affinity battle?

Carboxyhemoglobin (HbCO)

How do you treat CO poisoning?

High O2 to compete with CO for iron

What is a result from CO preventing O2 from unloading?

Functional anemia + tissue hypoxia

During relaxed state what occurs?

Hb can bind

During tense state what occurs?

Hb unloads to tissue

Which direction does the O2 dissociation curve shift during CO poisoning?

Left; less O2 released to tissue

Why does the skin turn cherry red during CO poisoning?

venous blood remains oxygenated

Why is there a false normal O2 saturation during CO poisoning?

Pulse oximetry(SpO2) reads HbCO as HbO2

What does CO bind in ETC?

Complex IV (cytochrome c oxidase)

What does CO block during mitochondrial disruption?

final electron transfer to O2

What pathway stops during mitochondrial disruption of CO poisoning?

oxidative phosphorylation —> ATP crisis

What form of glycolysis does the mitochondria shift to during mitochondrial disruption?

anaerobic —> increase lactate + increase ROS

What are the clinical consequences of mitochondrial disruption?

(Flu-like symptoms)

Brain: Confusion, headache (ATP shortage)

Heart: Arrhythmia, ischemia (high demand)

Muscles: Fatigue

Skin: Cherry red from oxygen retention in venous blood

What are many of the phenomena of CO poisoning associated with?

Haunted houses

What are the symptoms associated with CO poisoning?

Confusion, delirium, emotional disturbances, hallucinations

Why is normal PaO2 in CO labs?

detects free O2 dissolved in plasma

Why is SpO2 in labs for CO?

detected noninvasively by pulse oximetry

What are lactate levels in labs for CO? What do they lead to

High lactate —> lactic acidosis

What can you use in labs to confirm CO?

CO-oximetry

What diseases are important to rule out during CO?

cyanide and methemoglobinemia

What is the usual treatment for CO poisoning?

100% O2 by non-rebreather mask (speeds CO dissociation)

What form of treatment may be needed in severe cases of CO poisoning?

Hyperbaric O2 (increases dissolved O2, decreases CO half-life)

What are some prevention tips for CO poisoning?

Install CO detectors

maintain ventilation and heaters

Educate at-risk groups (elderly, infants, pregnant)

What happens to SaO2 during CO poisoning?

its below normal

What happens to SpO2 levels during CO poisoning?

False Normal

What happens to ATP production during CO poisoning?

large decrease

What happens to lactic acid during CO poisoning?

Increases

What test confirms diagnosis of CO poisoning?

CO-oximetry

What is peptic ulcer disease?

damage in lining of stomach or duodenum

What are the risk factors of peptic ulcer disease?

alcohol, smoking, stress, gum, spicy, fatty foods, spices, NSAID use, HP pylori infection

What is hematemesis?

vomit blood

What is melena?

Black tarry stool

What are the S/S of a peptic ulcer?

Hematemesis, melena, and blood occult in stool

What are the stages of peptic ulcer disease?

1st. Gastritis → 2nd. peptic ulcer → 3rd. perforation of GI tract

What are the gastro-protective factors?

Alkaline mucus, HCO3, gastroprotective prostaglandins

What are the gastro-harmful factors?

Hydrochloric acid

What are the two kinds of peptic ulcers?

Gastric and duodenal

What kind of peptic ulcer has pain that develops after you eat?

Gastric

What kind of peptic ulcer has pain that develops before you eat?

duodenal

What are all the things needed to produce hydrochloric acid?

Gastrin, acetylcholine, and histamin

What causes food coma?

bicarbonate in blood

What is formed in the bilayer and is activated by an enzyme?

Arachidonic acid

What enzymes can affect arachidonic acid?

Cox 1 and Cox 2

What happens as a result of Cox 1?

Produce platelet activating factors and gastroprotective factors (alk mucuous)

What happens as a result of Cox 2?

Increase pain, fever, and inflammation

How does NSAIDs and aspirin affect the arachidonic acid?

Inhibits Cox 1 and Cox 2

How do steroids affect arachidonic acid?

Inhibits enzyme that coverts phospholipids into arachidonic acid

What enzyme does H. Pylori produce?

Urease

What does Urease do?

Changes urea into ammonia

What does ammonia do?

Creates bubble where bacteria is protected from stomach

What treatment can help treat peptic ulcer disease?

acetaminophen (Cox 3 inhibitor)

Celecoxib and Meloxicam (Cox 2 selective inhibitor)

What is the main cause of peptic ulcer disease?

H. Pylori

Main way to diagnose peptic ulcer disease?

Esophagogastroduodenoscopy