Ventilation
Breathing
Respiration
Chemical reaction to release energy
Inspiration
Breathing in - active process
The external inter coastal muscles - contract
Internal inter coastal musicals - relax
The ribs are pulled upwards and outwards
The diagraphs muscles contract causing it to flatten increasing the volume of the thorax
The increased volume of the thorax results in the reduction of pressure in lungs
Atmospheric pressure now greater
Air forces out lungs
Expiration
Breathing out passive process
Internal inter coastal muscle contract
Ribs moves downwards and inwards
Diaphragm relaxes and returns to some shape
Decreasing the volume of the thorax
Increasing pressure in lungs
Air forces out the lungs
Pulmonary ventilation
Tidal volume x ventilation rate
Gas exchange in alveoli
Alveolar epithelium
Tiny air sacks create a large surface area for gas exchange
Epithelial cell are very thin short diffusion path way
Rich blood supply to maintain concentration gradient
Gas exchange in plants
Gas exchange at stomata
Oxygen diffuses out - if not needed for respiration
Carbon dioxide diffuses in - needed for photosynthesis
Reduce water loss in plants
Stomata closes at night when photosynthesis doesn’t occur
Xerophytic plants
Adapted to survive with limited water
Have structural features
Enable efficient gas exchange to occur
Whilst limiting water loss
Structure for xerophytes
Thicker cuticle - reduce evaporation
Hairs to trap moisture- increase humidity
Longer root network to reach more water
Thicker cuticle to reduce water loss
Terrestrial Insects
Exoskeleton is water proof
Prevents water loss
Hard fibrous material is for protection
However makes it hard for gasses to enter
Tracheal system
Trachea - is a network of internal tubes
Tubes have rings within them
Strengthen the tubes and keep them open
Tracheoles -branched out
Extend through your the tissue in insects to deliver oxygen to respiring cells
Spiracles -
Round value like openings
Long around the abdomen
Oxygen carbon dioxide enter and leave via spiritless
Trachea attached to these opening
Gas exchange in insects
- Along a diffusion gradient
When cells respire they use Up oxygen and produce co2
-Creating a concentration gradient
From tracheolos to atmosphere - Mass transport
Insects contract and relax their abdominal muscles to move hasses
This futher speeds up the exchange of respiratory gases
3.the end of the tracheols are filled with water
1.Muscle cells respite carrying out an anaerobic respiration - produced lactate
2.Lowers the water potential of fells
Water moves from tracheols into cells via osmis
3.Decrease volume in tracheols
4.More air from atm draws in
Adaptations to prevent water loss in insects
Small surface area to volume ratio
- water can evaporate
Waterproof exoskeleton
Spiricales open and close
Fish
Waterproof
Have small surface area to volume ratio
Require gas exchange - gills
Need adaptations
Adaptation for gas exchange
Large surface to volume ratio - created by many gill filaments covered in many gill lamellae
Short diffusion distance - due to capillary network in every lamellae and very thin lamellae
Maintain concentration gradient - countercurrent flow mechanism
Conentercurrent gradient
Water flows over gills opposite direction to blood following through capillary
Advantage -
Make sure the equilibrium of oxygen not reached
Ensures that a diffusion gradient is maintained across the entire length of the hill
Digestion
Large biological molecules are hydrolysed into smaller molecules that can be absorbed across cell membrane
Digestion in mammals
Carbs
Lipids
Protein
Begin in mouth continues in duodenum
Completed in illuem
Carbohydrates
Two enzymes hydrolyses into monosaccharides
- Amylase
- Membrane bound disaccharide
- Amylase is produced in salvariry gland
- Hydrolyses the polysaccharide into disaccharides maltose by hydrolysing glycosidic bonds
- Sucrase and lactase
- membrane bound
Hydrolyse sucrose and lactose into monosaccharides
Proteins
Large polymer molecules
- can be hydrolysed by 3 enzymes
- Endopeptidases
-hydrolyse peptide bonds between amino acids in the middle of polymer chain - Exopeptidases
- hydrolyse peptide bonds between amino acids at the end of the polymer chain - Membrane bound dipetodases
- hydrolyse peptide bonds between two amino acids
Lipids
1.Digested by lipase
2.Action of bile salts
- Lipase
-Produced in pancreas’s
-Hydrolyses the ester bond in triglycerides
-To for’ monoglycerides and fatty acids
2.bile salts
-produced in liver
-emulsify lipids to form tiny droplets - micelles
- micelles increase surface for lipase to act on
Lipid absorbtion
Micelles encounter the illuem epithelial cell due to non polar nature of fatty acid and mono glysceriedes
They can simply diffuse across cell surface membrane to enter the cells of epithelial
Once In cells
-Modify back into triglyceride inside the endoplasmic rectifulum and golgy box
Absorbtion
Products of absorbtion are digested across the cell lining of illuem
