Biology gas exchange

Gas Exchange Surfaces

Thin, permeable, large surface area, moist.

Type I Pneumocyte

Thin

Few mitochondria

Diffusion of gasses

Higher SA:V

Concentration Gradient

Difference in concentration drives passive diffusion.

Ventilation

Movement of air in and out of lungs.

Surfactant

Reduces surface tension in alveoli.

Inhaling Process

Diaphragm contracts, chest volume increases, pressure decreases.

Exhaling Process

Diaphragm relaxes, chest volume decreases, pressure increases.

Ventilation Rate

Number of inhalations/exhalations per minute.

Tidal Volume (TV)

Volume of air per breath inhaled/exhaled.

Vital Capacity

Maximum air volume lungs can hold.

Inspiratory Reserve Volume (IRV)

Air inhaled after a normal breath.

Expiratory Reserve Volume (ERV)

Air exhaled after a normal breath.

Gas Exchange in Leaves

Process involving stomata for gas exchange.

Stomata

Openings for gas exchange and water loss.

Waxy Cuticle

Prevents excess water loss in leaves.

Palisade Mesophyll

Site of photosynthesis with many chloroplasts.

Spongy Mesophyll

Facilitates gas exchange with air pockets.

Transpiration

Loss of water vapor from leaves.

Partial Pressure

Pressure of one gas in a gas mixture.

Cooperative Binding

Oxygen binding increases hemoglobin's affinity for more oxygen.

Bohr Shift

High CO2 lowers hemoglobin's oxygen affinity.

Fetal Hemoglobin

Higher affinity for oxygen than adult hemoglobin.