What is diffusion?
The movement of particles from an area of a higher concentration to an area of a lower concentration.
What is active transport?
The movement of particles against the concentration gradient. It require energy.
How did the coeliac disease mean the person lost weight, had not enough vitamins and minerals and felt tired?
Decreased surface area= less diffusion so less substances taken in by body- more excreted. Less capillaries= higher concentration of substances in blood so slower diffusion because less steep concentration gradient. Tiredness because of lack of glucose.
Different parts of heart:
Left ventricle
Aorta
Uses of valves in heart
Prevent back flow so blood can be pumped around body
Waste products 6 marker
Carbon dioxide from respiration released by lungs during exhalation
Urea from amino acids in liver released by kidneys during ultrafiltration, then send to bladder as urine and excreted
Excess water and ions lost in ultrafiltration and selective reabsorbtion in kidneys then in excretion
Warming up
Vasoconstriction- vessels further from skin so less heat lost via radiation
How shivering warms you up
Muscles contract, which requires energy from respiration, which is an exothermic reaction, so releases heat and warms you up
How brain detects temperature of blood
Thermoregulatory centre in brain detects temperature of blood that flows past it through receptors
How pancreas reacts to over supply of glucose
Released insulin, which causes glucose to be taken up by cells and glucose to be converted to glycogen and stored in muscles
Effect of sulfur dioxide
Acid rain
How to increase rate of photosynthesis
Lighter
Warmer