1. The Circulatory System:
The Intestine
VILLI= tiny protrusions in the intestine which help to absorb the products of digestion
Use active transport + diffusion to gain as much of the valuable materials, especially sugar, as possible
Villi help increase absorption because they:
Have a large surface area (squashed up)
Are moist
Are very close to a large network of capillaries (absorbed straight into blood stream)
Active Transport
Human Kidney
Vital for homeostasis
Works by filtering everything from blood and then reabsorbing all the sugar, as well as the mineral ions and water needed.
Active transport ensures ALL sugar is reabsorbed and diffusion makes sure mineral ions and water is reabsorbed in the right amounts
Hot day with little water intake = little urine (concentrated)
Cold day with large water intake = lots of urine (dilute)
Active Transport- requires energy to transport molecules from low to a high concentration
B3) Biology
Dialysis
Transplant
Much more readily available
Enables you to lead relatively normal life
No risk of rejection
No need for medicine
Eat what you like
Lead a normal life
Free from restrictions which come with regular dialysis sessions
Transpiration is the loss of water by evaporation from plants.
Plants lose water when they open the stomata in the leaves to let in carbon dioxide.
Transpiration happens faster in hot, dry, windy conditions.
Keywords: Active Transport, Osmosis, Diffusion, lungs, alveoli, villi, stomata, root hair cell
The Breathing System:
-Takes air into and out of your body.
-O2 diffuses into your bloodstream and CO2 diffuses out.
-Alveoli=large surface area, moist, thin walls.
The Circulatory System:
-The body transport system
consists of blood vessels, the
heart and blood.
-Human beings have a double
circulation.
-the heart works a s a pump
moving blood around the body.
-the 3 main types of blood vessel
are the Arteries (Away from heart),
veINs (INto heart) and capillaries.
The Blood
WHITE BLOOD CELLS- fights
PLATELETS- help blood to clot
PLASMA- holds dissolved
substances, glucose (taken from
the small intestine to the body
organs), CO2, waste products
(urea from the kidneys)
RED BLOOD CELLS- No
nucleus- more room for
Haemoglobin
Special shape with a lowered
Centre- greater surface area to
absorb gas
HAEMOGLOBIN- substance
which gains oxygen from the
lungs to form OXYhaemoglobin.
Then releases oxygen into cells.
body’s
cells
lungs
Keywords: Transpiration, artery, vein, capillary, heart, red blood cells, haemoglobin, plasma, platelets, an/aerobic respiration,

2. Growing Microorganisms
Micro-organisms grow in an agar culture medium with a carbohydrate energy source and various other vitamins, minerals and proteins
You need to take careful safety measures and use sterilized equipment to ensure the growth of uncontaminated cultures
Theory of Biogenesis
Pasteur did a series of experiments.
MICROBES CAUSE THINGS TO DECAY
THIS MEANS THAT LIFE (MICROBES) CANT JUST APPEAR FROM NOTHING, (SPONTANEOUS GENERATION).
Exchange in Plants
Need osmosis in roots (for water) and diffusion near stomata (for CO2)
Leaves thin + flat to increase SA for light and a waxy cuticle to prevent evaporation
Root hair cells increase SA because of long, thin hairs
Most minerals + ions needed taken through roots
Fermenters
Microbes can be grown on a large scale using fermenters
Fermenters have features such as an oxgen supply, stirrer to keep microorganisms in suspension and maintain an even temp, water-cooler jacket to remove excess heat and measuring instruments such as pH and temperature gauges
Mycoprotein is produced by allowing the fungus ‘Fusarium’ to grow on sugar syrup in aerobic conditions
Biogas – mainly methane – produced by anaerobic fermentation of a wide range of plants and waste materials that contain carbohydrates
Gets rid of waste, solves energy needs and is renewable, however hard to do it on a large scale
Bacteria and Food production
Bacteria are used to make cheese and yoghurt
Yoghurt is formed when bacteria act on lactose (sugar in the milk), producing lactic acid and changing the texture and taste of the milk
Different type of bacteria is added for cheese, making much more lactic acid is made and it is thicker (curds)
This is cooled and left in moulds to set and then more bacteria is added to give different flavours
Antibiotics
kill bacteria
Penicillin
Discovery of penicillin was made by Alexander Fleming. Penicillium mould is used as it provides more penicillin, as it is made in a fermenter.
Keywords: Biogas, biofuels, Biogenesis, Pasteur, mycoprotein, antibiotics, Flemming
Yeast and Food production
Yeast is a single celled organism which can respire both aerobically and an anaerobically
Aerobic respiration produces CO2 and water and is used to make bread rise
Anaerobic respiration produces CO2 and ethanol, the process is known as fermentation
This is used in the production of beer, wine and other alcoholic drinks
Effect of Exercise
Energy from respiration used to make muscles contract
When this happens, you need more respiration to take place (ie more O2 + glucose, quicker CO2 release)
Causes increased heart/breathing rate
Arteries dilate  more blood for muscles increases oxygen/glucose supply CO2 is removed quicker
Anaerobic Respiration
Your everyday muscle movements are made possible by AEROBIC respiration
If heart rate is increased, blood cant supply O2 quick enough
Anaerobic respiration doesn’t involve O2 and is less efficient
Glucose  Lactic Acid (+ energy)
Lactic acid needs to be got rid of (by reacting with O2 to form CO2 + water) = OXYGEN DEBT
Biofuels
Ethanol based fuels can be produced from anaerobic fermentation of sugar cane juices by the enzyme carbohydrase.
+ves = does’nt produce toxic gases, much cleaner and can be mixed with petrol, carbon neutral
-ves = needs lots of space, poor countries grow cash crops instead of feeding people  starvation.
BREATHING
CELLULAR RESPIRATION
Muscle cells carrying out
Keywords: kidney, dialysis, transplant, immunosuppressant drugs, microbes, fermentation, yeast, bread, alcohol, bacteria, yoghurt lactic acid,