Biology Experiment: Lipid Extraction Procedure

Questions and Answers

What is the primary role of pulmonary surfactant in the lungs?

To increase the pressure in the alveoli

To serve as an energy source for lung cells

To reduce surface tension at the air-liquid interface (correct)

To facilitate gas exchange

Which of the following symptoms is NOT associated with Respiratory Distress Syndrome (RDS) in newborns?

Poor feeding

Excessive yawning (correct)

Apnea

Cyanosis

What is the estimated pool size of surfactant in full-term infants?

200 mg/kg

100 mg/kg (correct)

150 mg/kg

50 mg/kg

Which treatment option is commonly used for managing RDS?

Prenatal corticosteroids and postnatal surfactant replacement therapy Signup and view all the answers

Which of the following descriptions best characterizes the radiological findings in RDS?

A reticulogranular 'ground glass' appearance with air bronchograms Signup and view all the answers

Which of the following is a common risk factor for developing Respiratory Distress Syndrome?

Premature birth Signup and view all the answers

What biochemical composition primarily makes up pulmonary surfactant?

Phospholipids and proteins Signup and view all the answers

Which physiological response is indicative of respiratory distress in newborns?

Tachypnea Signup and view all the answers

What is the purpose of homogenizing the pig’s brain in an ether-alcohol mixture?

To extract total lipids Signup and view all the answers

What is the primary chemical function of potassium bisulphate (KHSO4) in this experiment?

To promote dehydration Signup and view all the answers

What compound is produced when glycerol is heated with KHSO4?

Acrolein Signup and view all the answers

During the experiment, what happens to the 2/3 portion of the ether-alcohol extract after being evaporated?

It becomes a syrupy consistency Signup and view all the answers

In this procedure, what is the result of treating fat with alcoholic KOH?

Dehydration to form acrolein Signup and view all the answers

What is the significance of using glass beads in the Erlenmeyer flask during heating?

They prevent bumping during the heating process Signup and view all the answers

What odor is notably associated with the dehydration of glycerol in this experiment?

Pungent irritating odor of acrolein Signup and view all the answers

What is the primary observation noted when heating the glycerol solution with KHSO4?

Production of peculiar odor Signup and view all the answers

What is the main purpose of heating the aqueous layer to reduce it to about 20 ml?

To concentrate the solution for further tests Signup and view all the answers

Which chemical is mentioned as part of the extraction process before the test on lecithin?

Ether Signup and view all the answers

What is observed when the acrolein test on glycerol yields a burnt odor?

Presence of glycerol Signup and view all the answers

What is the significance of filtering the precipitate after mixing with ether and acetone?

To isolate lecithin from the mixture Signup and view all the answers

During the test on lecithin, which of the following solutions is initially added to the syrup consistency?

Ether Signup and view all the answers

In the context of the described process, what does the term 'surfactants' refer to?

Substances that decrease surface tension Signup and view all the answers

What is likely the expected outcome when adding a few drops of the lecithin solution into water?

Homogeneous mixing without separation Signup and view all the answers

What final step is performed after the ether extract has been combined with acetone?

Filtering to separate lecithin Signup and view all the answers

What role does surfactant play in the alveoli during respiration?

It prevents alveolar collapse by reducing surface tension. Signup and view all the answers

What is the primary component of lung surfactant responsible for reducing surface tension?

Dipalmitoylphosphatidylcholine (DPPC) Signup and view all the answers

What is the consequence of insufficient surfactant production in preterm infants?

Respiratory Distress Syndrome (RDS) Signup and view all the answers

What percentage of lung surfactant is made up of lipids?

90% Signup and view all the answers

Which of the following is NOT a factor that can lead to Respiratory Distress Syndrome (RDS) in adults?

Excessive surfactant levels Signup and view all the answers

What is the composition ratio of proteins to lipids in lung surfactant?

10% proteins, 90% lipids Signup and view all the answers

What condition is directly associated with damaged surfactant-producing pneumocytes in adults?

Acute Respiratory Distress Syndrome (ARDS) Signup and view all the answers

Why is maintaining adequate surfactant levels critical for lung function?

It allows faster inflation of alveoli. Signup and view all the answers

Which statement accurately describes the primary function of Type II alveolar epithelial cells?

They synthesize and secrete surfactant to reduce surface tension. Signup and view all the answers

What is the significance of the L/S ratio in assessing fetal lung maturity?

A ratio of two or above suggests a major shift in surfactant composition indicating maturity. Signup and view all the answers

What is the primary role of lipids in the surfactant system?

They are responsible for lowering surface tension within the alveoli. Signup and view all the answers

During which stage of lung development do the components of the surfactant system begin to appear?

Canalicular stage, between 16 to 26 weeks. Signup and view all the answers

In which scenario might respiratory distress syndrome (RDS) occur in adults?

As a result of injury to surfactant-producing pneumocytes. Signup and view all the answers

What is primarily contained in lung surfactant?

60-70% dipalmitoylphosphatidylcholine along with surfactant proteins. Signup and view all the answers

What characterizes the canalicular stage of lung development?

It is the stage where components of the surfactant system begin to appear. Signup and view all the answers

Which cells are primarily responsible for forming the alveolar wall?

Type I cells. Signup and view all the answers

Study Notes

Lipids and Glycerol Experiments

Homogenize 30 grams of pig's brain with an ether-alcohol mixture.
Filter the homogenized material to obtain an ether-alcohol extract, which contains total lipids.
Prepare a test solution by combining powdered KHSO4 with glycerol and heating to produce a distinctive odor indicating dehydration.
The presence of triglycerides can be identified using the acrolein test, where glycerol is dehydrated to form acrolein under heat, emitting a pungent smell.
Isolate lecithin from the remaining lipid extract by concentrating it and adding ether followed by acetone, resulting in a precipitate that is mostly lecithin.

Respiratory Distress Syndrome (RDS)

RDS primarily affects preterm infants due to inadequate pulmonary surfactant.
Surfactant, a mix of phospholipids (70%-80%) and proteins (10%), reduces surface tension in the alveoli to prevent collapse.
Treatment options include prenatal corticosteroids and postnatal surfactant replacement therapy for infants with RDS.
Alveolar maturity can be assessed by the L/S ratio (lecithin/sphingomyelin) in amniotic fluid; a ratio of 2 or above indicates lung maturity.

Composition and Function of Pulmonary Surfactant

Surfactant consists of approximately 90% lipids, primarily dipalmitoylphosphatidylcholine (DPPC), and 10% proteins.
Key roles of surfactant include:
- Lowering surface tension, facilitating easier inflation of alveoli during inhalation.
- Preventing atelectasis by reducing the pressure needed to reinflate collapsed alveoli.

Pathophysiology of RDS

Insufficient surfactant production leads to RDS, which is a major cause of neonatal mortality in Western countries.
Adults can also experience RDS if surfactant-producing pneumocytes are damaged by factors such as infection or trauma.

Key Development Stages of Surfactant

Type II alveolar epithelial cells synthesize surfactant and become functional around 24-34 weeks of gestation.
The canalicular stage of lung development occurs between 16-26 weeks.
Alveoli develop throughout the last trimester and into the early postnatal months, impacting surfactant production and infant respiratory health.

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Description

This quiz covers the experimental procedure for extracting total lipids from pig's brain using an ether-alcohol mixture. It includes steps such as homogenization, filtration, and reaction observations. Test your knowledge on the techniques and chemical processes involved in lipid analysis.