TOPIC 2-ORGANISATION Flashcards
what is a tissue
a group of cells
explain what is meant by the term ‘organ system’
an organ system is a group of organs working together to perform a particular function
why can enzymes be described as a biological catalyst
this is because enzymes are folded proteins made by an organism
why do enzymes only usually catalyse one reaction
enzymes have a specific active site and only specific substrates can fit .
what does it mean when an enzyme has denatured
if a temperature is too high it breaks the shape of the enzyme and so it doesn’t fit in the active site
what’s the test for sugars
Benedict’s test was the test for sugars ( benedict solution )
what’s the test for starch
iodine solution is the test for starch ( iodine solution )
what’s the test for protein
Biuret test is the test for proteins ( biuret solution )
what’s the test for lipids
Sudan III test is uses to test for lipids ( Sudan solution )
what controls your resting heart rate
a group of cells in the right atrium act as a pace maker , they send impulses causing them to contract
… function
arteries
capillaries
veins
arteries - carry blood away from the heart
capillaries - these are involved in the exchange of
materials at the tissues
veins - carry blood to the heart
structure of arteries
pump the blood out a high pressure so strong and elastic walls , contain thick layers of muscle , elastic fibres to stretch .
structure of capillaries
one cell thick , very small lumen , permeable walls so substances can diffuse in and out
structure of veins
large lumen , have valve to keep correct blood flow , less thick walls .
explain the structure of red blood cells
biconcave disc structure gives large surface area , don’t have a nucleus so more room to carry oxygen and contain haemoglobin
