Organisms Exchange Substances With Their Enviroment Flashcards
(45 cards)
Describe the respiratory system of fish
•Water enters fish’s open mouth -operculum closes
•Fish lowers base of mouth increasing volume of water in mouth
•Fish closed mouth raises base of mouth - operculum opens
•Due to high pressure water Is forced through gills and leaves through operculum
What are the structures of the gills
Gill arch
Filament
Lamella- folds on filament to increase SA
operculum- fill flap
Why do fish use counter current flow
Maximises diffusion if oxygen as it maintains the concentration gradient
Describe respiratory system of insect
•Air enters spiracles - pore of surface
•air moves through trachea which branches off into tracheoles
•division continues till they penetrate individual cells
What are the adaptations of insect respiration
Water at end of tracheoles used to increase water potential in cells when lactic acid produced
Abdominal pumping
Describe the trachea and bronchi
Both contain cartilage to keep airways open, ciliates epithelial cells and goblet cells worth prevent pathogens entering lungs and elastic fibres aloe movement
Describe the bronchioles
No cartilage. lots of squamous epithelial cells and elastic fibres
Describe the alveoli
One layer of squamous epithelial cells providing short diffusion distance large SA, high blood flow, high ventilation and high moisture. contain collagen to prevent bursting
What are the steps of inspiration
Diaphragm and external intercostal muscles contract as internal intercostal muscles relax so thorax volume increase air flows into lungs
What are the steps of expiration
Diaphragm and external intercostal muscles relax as internal intercostal muscles contract so thorax volume decreases air flows out of lungs
What are xerophytes
Plants that have adapted to dramatically reduce water loss
What are the adaptations of xerophytes
Layer of hairs to trap water
Less stomata
Curled leaves
Waxy cuticle
Stomata sunk into pits to create humid environment
What does Bile do?
Produced the liver and stored and secreted by the gall bladder caused emulsification of lipids
What are micelle ?
When Lipids are broken down into fatty acids and mono-glycerides by bile and held together by bile salts
How are lipids absorbed into the blood
Micelle move to ileum in the small intestine the fatty acids and monoglycerides diffuse through and turned into a triglyceride at the smooth-ER then to the Golgi body where a protein is added forming a chylomicron which leaves cell by exocytosis into lymphatic system and hydrolysed in blood for fatty acids and mono glycerides
Describe carbohydrate digestion
Salivary amylase hydrolyses stach in the mouth pancreatic amylase in the stomach hydrolysed the alternate glycosidic bonds in the starch forming maltose which is hydrolysed by Maltase on the lining of the ileum into alpha glucose
Describe the digestion of lipids
Lipase breaks down lipids by hydrolysing the ester bond forming fatty acids and mono-glycerides bile from the hall bladder emulsifies the rest of the lipids and bile salts hold the fatty acids and mono-glycerides in micelle
Describe Protein digestion
•Endopeptidase: hydrolyse peptide bond between AA in central region
•Exopeptidase: hydrolyse the peptide bond on the terminal AA at the end of the peptide releasing Dipeptides and AA
•Dipeptidase: are membrane bound lining the ileum hydrolyse bind between two AA of a dipeptide
Describe Haemoglobin
Quaternary protein made from 4 poly peptide chains containing 4 haem groups each contain a Fe2+ which attaches O2. There are 270million haemoglobin on a red blood cell
Define Affinity
How much attraction O2 has to haemoglobin
Define Association and Dissociation
Association- haemoglobin binding to O2
Dissociation- haemoglobin releasing O2
Define high/low affinity
•High - associates O2 readily in high O2 concentration
•Low - dissociates O2 easily in low O2 concentration
How does affinity for O2 to haemoglobin change as O2 is added?
1st O2 is difficult to bind due to the close association of the peptide chains
2nd and 3rd are easy as haem group has been opened for them
4th is difficult as there is low chance of a collision with the last haem group
Describe the Bohr shift
O2 affinity is reduced in presence of CO2 due to low ph of CO2 in water and high temp from respiring muscles changes shape of haemoglobin so O2 lost
