Organisation Flashcards
The five levels of organisation
cells, tissues, organs, organ systems, organisms
Small intestine
what does it have + why
villi for large surface area
lots of capillaries supplying villi for good blood supply
short diffusion distance
Path of food
mouth, oesophagus, stomach, small intestine, large intestine, rectum, anus
Where enzymes are:
amylase-
protease-
lipase-
whats in liver+ what does it do
whats in gall bladder
amylase- salivary glands + pancrease
protease- stomach + pancreas
Lipase- pancreas
Liver- bile which speeds up enzyme action
gall bladder- stores bile before its released into small intestine
how enzymes work
the substrate binds to the active site and the enzyme catalyses the reaction
Factors affecting enzymes
temp= to far above optimum temp will denature it
pH= too far above or below optimum pH will denature it
Bile
enzymes in the pancreas + small intestine work best in alkaline conditions, so bile is alkaline, therefore it neutralises HCL in stomach
it also helps to digest fats= emulsifies them to form smaller droplets which increases SA for eznymes to act on
What do the enzymes work on and what are they made of?
AMYLASE: works on carbohydrates (starch), made from simple sugars e.g. glucose
PROTEASE: works on proteins, made from amino acids
LIPASE: works on lipids (fats + oils), made from fatty acids and glycerol
Where are the enzymes produced and where are their sites of action?
AMYLASE: produced in salivary glands + pancreas, site of action is small intestine + mouth
PROTEASE: produced in pancreas, stomach + small intestine, site of action is small intestine + stomach
LIPASE: produced in pancreas + small intestine, site of action is small intestine
Components of blood + function
plasma= transports blood cells + chemicals around the body, straw coloured liquid
platelets= helps blood clot, smaller than red/ white blood cells
white blood cells= protects body against infection, has a nucleus, larger than red blood cell
red blood cells = carries oxygen around to body’s cells. has haemoglobin which is a pigment that binds to oxygen
How are red blood cells specialised for their function?
no nucleus= more space for haemoglobin
bioconcave= more surface area for oxygen
What are the three blood vessels like + what are they for?
Arteries= carry blood away from the heart, high pressure, thick muscular walls + small lumen (keeps high pressure)
Veins= carry blood towards the heart, large lumen (keeps low pressure), has valves to prevent back-flow of blood
Capillaries= brings blood to cells of body, subsrances diffuse in/ out of the blood, walls only one cell thick so short diffusion path
Path of oxygen through lungs + other parts of lungs
Mouth + nose- trachea- bronchus- bronchioles- alveoli
Other: ribs, intercostal muscle, diaphragm
Alveoli
good blood supply, CO2 diffuses in O2 diffuses out, maintains a steep conc gradient, walls are one cell thick so short diffusion path, large SA to volume ratio
what do gills do in fish?
- large SA
- good blood supply
- one cell thick= faster diffusion
- ventilated
- counter-current (water ans blood go opposite ways which maintains steep conc gradient)