GAS EXCHANGE (savemyexams notes)

What is gas exchange in organisms?

Gas exchange is the process by which organisms acquire oxygen from their environment and release carbon dioxide back into their surroundings.

What is the primary waste product of aerobic respiration?

Carbon dioxide is the primary waste product of aerobic respiration.

What factors affect the rate of diffusion in gas exchange?

Factors include the size of the respiratory surface, concentration gradient, and diffusion distance.

Why can't large multicellular organisms rely solely on diffusion for gas exchange?

Because an increase in size results in a smaller surface area to volume ratio and greater diffusion distance.

What are the properties required for effective gas exchange surfaces?

They must be permeable, thin, moist, and have a large surface area.

How is a concentration gradient maintained in gas exchange?

Through a dense network of blood vessels and continuous blood flow that constantly transports gases.

What is the role of alveoli in gas exchange?

Alveoli are the gas exchange surfaces in humans, where O2 and CO2 diffuse between air and blood.

What adaptations do mammalian lungs have for gas exchange?

Mammalian lungs have many small alveoli, extensive capillary networks, and the ability to regulate airflow.

What is the process of inspiration in ventilation?

Inspiration occurs when the diaphragm contracts and flattens, increasing chest volume and decreasing pressure, drawing air into the lungs.

What happens during passive expiration?

Passive expiration occurs due to the recoil of the lungs after being stretched, resulting in decreased volume and increased pressure, forcing air out.

What does tidal volume refer to?

Tidal volume is the volume of air inhaled and exhaled during normal breathing.

What is vital capacity in terms of lung volumes?

Vital capacity (VC) is the total amount of air exhaled after taking a deep breath, calculated as VC = TV + IRV + ERV.

What is stomatal density?

Stomatal density refers to the number of stomata per unit area on a leaf.

How does the structure of leaves facilitate gas exchange?

Leaves have stomata for gas exchange, a waxy cuticle for moisture retention, and spongy mesophyll with air spaces to facilitate gas movement.

What is the role of guard cells in plants?

Guard cells control the opening and closing of stomata to regulate gas exchange and water loss.

What is the Bohr effect?

The Bohr effect describes the decrease in hemoglobin's affinity for oxygen as carbon dioxide levels increase, allowing for more oxygen release in respiring tissues.

What does the oxygen dissociation curve represent?

The oxygen dissociation curve shows how hemoglobin's affinity for oxygen changes at different partial pressures of oxygen.

What is cooperative binding in hemoglobin?

Cooperative binding refers to the increased likelihood of subsequent oxygen molecules binding to hemoglobin once the first molecule is attached.

Why does fetal hemoglobin have a higher affinity for oxygen than adult hemoglobin?

Fetal hemoglobin has a higher affinity for oxygen to ensure oxygen uptake from the mother's blood at lower partial pressures.