Respiration/Heart/Lungs (Bio) Flashcards
(66 cards)
aerobic respiration
glucose + oxygen -> carbon dioxide + water
C6H12O6 + 6O2 -> 6CO2 + 6H2O
- exothermic
- 38 ATP released
where to get reactants for aerobic respiration
glucose from digestion of food (stored in muscles and liver as glycogen)
oxygen from blood
where does aerobic respiration take place
in mitochondria
- more mitochondria in a cell = more metabolically active
why do boys need to eat more than girls
more muscle mass/respiration/glucose needed
5 uses of energy in body
anabolic reactions: synthesis of larger molecules from smaller ones (protein synthesis)
catabolic reactions: break down larger molecules into smaller ones (digestion)
muscle contraction (movement, peristalsis, breathing)
maintain stable body temp. (shivering, sweating)
active transport (moving mineral ions from soil into root hair cells)
aerobic respiration during exercise
heart rate increases - increase blood supply to and from muscles
arteries supplying active muscles dilate (get wider) - for same reasons
breathing rate and depth increase - increase grass exchange at lungs
muscles convert stored glycogen-> glucose
anaerobic respiration (animals)
glucose -> lactic acid
C6H12O6 -> 2C3H6O3
- exothermic
- 2ATP released
- v fast- less bonds broken
where does anaerobic respiration take place
cytoplasm
lactic acid causes…
muscle fatigue (tire and stop contracting as efficiently)
pain (soreness due to reduced pH)
oxygen debt
waste lactic acid needs to be removed from the body and oxygen is needed for this to happen
- lactic acid from anaerobically respiring muscles diffuses into the blood
- converted back to glucose in the liver (using ATP)
anaerobic respiration in plants (and why is this needed? and other uses?)
fermentation:
glucose -> ethanol + carbon dioxide
C6H12O6 -> 2C2H6O + 2CO2
- used when plants are flooded so there is very low oxygen concentration in soil
- used in manufacture of alcoholic drinks / bread
aerobic vs anaerobic respiration:
diffusion
NET movement of particles
down a concentration gradient
through a partially/selectively permeable membrane
until an equilibrium is reached
side length vs SA:V ratio
as side length increases, SA:V ratio decreases
diffusuion in unicellular organisms
- relatively large SA:V ratio
- relatively low distance between cell membrane and centre of cell (substances do not have to travel very far)
- can enter directly from environment, waste products leave the same way
diffusion in multicellular organisms
small SA:V
large distance
exchange cannot happen fast enough
so have exchange surfaces and transport systems to accommodate this
how small intestine is adapted for exchange
highly folded surface and cells with highly folded cell membrane (increase SA)
1 layer of epithelial cells on the surface (decrease diffusion distance)
good blood supply (maintain concentration gradient)
how gills adapted
each gill has lots of smaller filaments (increases SA)
good blood supply
how are roots adapted
highly branched root network
surface covered with root hair cells
(both increase SA)
how are leaves adapted
little hairs (SA)
stomata allow gases in and out (Dd)
spongy mesophyll layer allows air to circulate inside the leaf (Dd)
Ficks Law
rate of diffusion proportional to:
surface area x concentration difference / diffusion distance
so
rd prop to surface area
to concentration difference
to 1 / diffusion distance
function of lungs
enable breathing
move air in and out of lungs (ventilation)
provide a surface area for gas exchange
inhalation
diaphragm contracts and moves down
- increase volume of chest cavity
- decreases pressure of chest cavity
- air moves in and fills lungs
+ intercostal muscles contract - ribs move up and out
exhalation
diaphragm relaxes and moves up
- decrease volume of chest cavity
- increase pressure of chest cavity
- air moves out and empties lungs