Unit 2 + 3 Flashcards
what is the role of the golgi apparatus
involved in the process and packaging of proteins
role of lysosomes
its a digestive enzyme which digests worn out parts of the cell
what are the roles of a slime capsule
- stops the cell from drying out
- protects it from enzymes
why are viruses acellular
because they do not have a cellular structure
what is cell fractionation
when cells are broken up and their organelles are seperated because they have different densities
why is the solution for cell fractionation placed in cold water
it reduces enzyme activity
why is the solution for cell fractionation placed in an isotonic solution
it prevents the cell from shrinking or bursting
why is the solution for cell fractionation placed in a buffered solution
so the pH stays the same
what are some limitations to using a TEM
- may contain artefacts
- image is 2D
what is binary fission
how bacteria reproduce as it is an asexual process
what makes up the bilayer
phospholipids and protein
define active transport
the movement of particles from low to high concentration across a semi-permeable membrane
define osmosis
the movement of water from a high to low concentration against a semi permeable membrane
give 3 ways you can increase the rate of diffusion
- increase concentration gradient
- increase surface area
- change diffusion path
what are spiracles
microscopic holes in the body of insects which can open + close
what causes spiracles to open
a rise in CO2
link haemoglobin with affinity
when its in the heart its affinity is high so it carries a lot of oxygen
when it leaves the heart its affinity lowers so it unloads it quicker
what are the 3 compartments of a fish gill
- flap
- bar
- filaments
how are gills beneficial to fish
they contain many lamellae which increases its surface area
what is meant by a counter current
when blood flows one way and water flows the other
how are gills efficient at diffusion
they ensure the oxygen in water is always just higher than the water so diffusion can occur
what circulatory system do humans have
what system does a fish have
humans - double
fish - single
what are the 2 phases of the cardiac cycle
diastole and systole
what is the diastole phase
it refers to the ventricular filling
what is the systole phase
the ventricular contraction
when do the AV valves open
when the pressure in the atrium is greater than the pressure in the ventricle
give the features of an artery
- high pressure
- elastic tissue
- smooth inner endothelial lining
how does the elastic tissue benefit the artery
it allows it to stretch and recoil
how does the smooth inner endothelial lining benefit the artery
it removes friction so more blood flow
give the features of a vein
- thin collagen layer as pressure is low
- valves which prevent backflow
give the features of capillaries
- single cell walls of endothelial for easy diffusion
- narrow lumen which reduces flow rate giving more time for diffusion
what is meant by tissue fluid
when the liquid plasma leaks out of the capillaries
what links companion cells
plasmodesmata
what is a stylet
what aphids use to penertrate phloem tubes and sip sugary sap
describe the cohesion - tension theory of water transport
- the stomata in the leaves open as transpiration increases
- as transpiration occurs the water potential decreases
- water is pulled up the xylem which creates tension
- water molecules stick together via cohesion
how is the highest pressure produced in the left ventricle
stronger contractions / thicker muscle
which vessel has the thickest muscles
the left ventricle
what would happen if babies are born with a hole between their right and left ventricle
the oxygenated and deoxygenated blood would mix together so the volume of oxygenated blood would be lower
whats an advantage to using a pH meter over a colourimeter
greater accuracy as it gives a numerical reading
what type of bond is broken when chain of amino acids is hydrolysed
peptide
how does an inhibitor stop an enzyme working
- inhibitor is similar shape to substrate
- so it binds to the active site
- this stops the enzyme binding to actual substrate
explain the role of the diaphragm in breathing out
- diahphragm moves up
- this reduces the volume in the thorax / increases pressure
- so the pressure in the thorax is higher than outside
