Biology - CGP wrong answers.. Flashcards
how is the structure of gill filaments adapted to its function
gill filaments are folded into lamellae increase SA:VOL for gas exchange to occur so increase rate of diffusion
explain how an insect pumps air in and out of body
changes volume of body with rhythmic abdominal movements = changes in pressure and air is drawn into spiracles
describe how fluid is insects is involved in gas exchange
allows O2 to dissolve and be transported into respiring tissue,
CO2 diffuses in opposite direction
explain how changes in buccal cavity of bony fish allow gills to be ventilated
-buccal cavity lowers increasing VOL and decrease PRESSURE
- water moves in
- mouth closes causes buccal cavity to raise
- Decrease VOL increase PRESSURE
- water pushes out the operculum flap and over the gill filaments where gas exchange happens
suggest why there is a difference in heart rate between standing up and lying down
heart rate increases when standing up as blood has to be pumped harder against gravity
what happens to cell when solution outside is hypotonic
cell will become turgid
state two roles of glycoproteins in a cell
- act as receptors for cell signalling
- act as antigens
explain why glucagon affects liver cells but not skeletal muscle cells
glucagon is not complimentary to receptor on skeletal muscle cell
suggests why membrane permeability increases when pH is decreased
protein denatured by acidic pH = change shape so can’t control cell activity increase membrane p.
the optimum ph for trypsin is ph 8. describe and explain what will happen to rate of reaction above this pH
OH- ions in alkaline solution will interfere with the ionic/hydrogen bonds that hold trypsin’s tertiary structure in place. This will make the active site change shape so the rate of reaction will decrease. The enzyme will denature
