Movement of Substances (osmosis, direct transport, diffusion) Flashcards
how does oxygen get into the body
oxygen is breathed in, in air - travels down trachea - bronchus - lung - bronchioles - alveoli - diffuses into blood
what happens to oxygen inside a capillary
moves into red blood cells - combines with haemoglobin
why does oxygen need to move around the body
body cells require oxygen for aerobic respiration in mitochondria to create energy - energy used to move, generate heat (enzymes), growth (creating new cells), chemical reactions (digestion) etc
concentration
how many particles are in a fixed area/volume
movement of particles in diffusion
move from high to low concentration until even distribution (equilibrium)
how is it possible for oxygen to move from alveolus to capillary
alveolus & capillary wall are 1 cell thick - easier for diffusion to occur (high to low concentration - alveolus has high, capillary has low)
how is it possible for carbon dioxide to move from capillary into alveolus
co2 created as waste product of respiration in bloodstream in plasma - diffuses out down concentration gradient
why is it important for co2 to be removed from body
it’s toxic/poisonous - cannot be allowed to build up - can make body too acidic - affect enzymes
how is it possible for co2 to move from air into palisade cells in leaf
higher concentration outside of leaf -lower inside. diffuses into leaf through stoma, through air spaces between spongy mesophyll. even lower concentration inside palisade cells as constantly used in photosynthesis
why does co2 diffusion not occur in plants at night, and what does the plant do because of this
there is no concentration gradient as the plant is not photosynthesising due to lack of light. stomata closes so the plant does not lose excess water
what is urea and why is it found in liver
toxic chemical - dissolved in urine - extra protein cannot be stored - liver breaks it down into urea
how does urea move out of liver cells into blood plasma
diffusion - higher concentration in liver - lower in blood plasma (blood flows constantly and takes it away)
what happens to urea in kidneys
higher concentration in blood plasma -lower in kidneys - diffusion. filtered - moves to bladder - excretion
factors affecting rate of diffusion
temperature, sa, concentration gradient
how does a high temperature affect rate of diffusion
higher temp - particles have more kinetic energy - increased motion - move and diffuse quicker. vice versa for low temperature
how does large sa affect rate of diffusion
larger sa - more space for particles to diffuse across - quicker. vice versa for smaller sa
how does a steep concentration gradient affect diffusion rate
greater difference - steeper gradient - faster diffusion as trying to move from a place of high to low. vice versa for shallow concentration gradient
how is amoeba specialised for diffusion
not regular shape - lots of psedopods etc. increases sa - higher rate of diffusion
how are humans adapted to low sa:v ratio
transport systems i.e circulatory system (tubes/vessels). specialised exchange surfaces i.e. lungs (thin, moist, large area)
sa
outer layer of something
v
amount of space something occupies
sa:v ratio
amount of sa per unit v of an object
ventilation
movement of air in and out of an animal
how are lungs adapted for exchange of gases, and which gases are these
gases: co2, o2, nitrogen, argon, water vapour. adaptations: large sa - lots of rounded alveoli. short diffusion distance - lots of capillaries nearby - wall 1 cell thick. steep concentration gradient - much co2 in body, not in air - much o2 in air, not body - constantly breathing
how is the small intestine adapted for diffusion, and what substances are exchanged
substances: nutrients, fats, carbs, proteins. adaptations: large sa - millions of villi - very long - highly folded. short diffusion distance - wall 1 cell thick - nearby capillaries & blood vessels. steep concentration gradient - lymph vessel runs through centre to transport fatty acids and glycerol - blood constantly moves - body regularly eats and egests.
how are fish gills adapted for diffusion, and what substances are exchanged
substances: o2, co2, h2o. adaptations: large sa - lamellae - protrusions - filaments. short diffusion distance - rich blood supply - thin walls. steep concentration gradient - counter-current flow principle - ventilation.
how are plant roots adapted for diffusion, and what substances are exchanged
substances: water, minerals. adaptations: large sa - long root hair. short diffusion distance - thin cell walls. steep concentration gradient - lots of water outside, not in - xylem and phloem - transpiration
how are plant leaves adapted for diffusion, ad what substances are exchanged
substances: co2, o2, water vapour. adaptations: large sa - large leaves, but thin. short diffusion distance - thin - thin cell walls - stomata - air spaces. steep concentration gradient - ventilation - photosynthesis.
process of osmosis
net movement of water from a dilute solution (higher concentration [of water]) to a concentrated solution (lower) across a semi-permeable membrane
solvent
liquid that things are dissolved into
solute
something that is dissolved in a solvent/water
solution
mixture - solute dissolved in solvent
soluble
something that is dissolvable/ in a solvent
insoluble
something not dissolvable in a solvent
concentrated
lots of solute dissolved in solvent - high ratio
dilute
not much solute dissolved in solvent - low ratio
equilibrium
equal distribution - balanced across all parts
how does sa affect osmosis
greater size of semi-permeable membrane - more space to move across
how does temperature affect osmosis
particles have more kinetic energy - move faster - osmose faster - move across membrane faster
why is osmosis important in animal cells
water controls chemical reactions (eg digestion), needed to make cytoplasm, keep hydrated - full of moisture, lubricant - trap bacteria, to make blood
what 3 factors affect osmosis
sa, temperature, length of osmosis pathway
why is osmosis important in plant cells
water controls chemical reactions (eg photosynthesis), needed for cytoplasm and vacuoles, keeps cells turgid (stems), keep hydrated
define crenation
the contraction of the edges of a cell after exposure to a hypertonic solution, due to water loss via osmosis
define hypertonic
water leaves cell via osmosis as the concentration of solution is high
define hypotonic
water enters cell via osmosis as the concentration of solution is low
define isotonic
water does not enter or leave the cell - equilibrium
what happens to a plant and animal cell in a hypertonic solution
if a cell loses water is will shrink and lose its shape. animal - crenation. plant - plasmolysis.
what happens to a plant and animal cell in a hypotonic solution
if a cell takes in too much water is will swell and may burst. animal - lysis. plant - turgid
what happens to a plant and animal cell in an isotonic solution
animal - normal. plant - flaccid.
what is active transport
the movement of substances (usually charged particles or larger molecules that would struggle to move by diffusion) from one cell to another against the concentration gradient
why is active transport necessary for plant roots absorbing minerals
minerals are in roots and need to get to leaves; minerals are dilute in soil and concentrated in leaves
what are similarities of osmosis and diffusion
do not require energy, move down concentration gradient, high concentration to low
what are similarities of osmosis and active transport
needs a membrane, movement of liquids/solutes
how is active transport different from osmosis and diffusion
goes against concentration gradient, requires energy, involves carrier proteins, movement of charged particles/larger molecules
how do transport proteins and solute molecules fit together
they are unique complimentary shapes
describe the process of active transport
transport protein on semi-permeable membrane. transport protein recognises solute in dilute solution, grabs it. protein rotates in membrane and releases solute inside cell (high concentration) using energy. protein rotates back again (often using energy)
why are air pockets important in soil for active transport
oxygen required for respiration - make energy - to do active transport
why does waterlogged soil negatively affect plants
less oxygen in soil - less able to respire - less energy - less active transport - less vitamins and minerals in plant
why is there a high concentration of minerals within a plant
minerals build up as they are used in molecules within in the plant (eg Mg in chlorophyll)
how are plant roots adapted for exchange of materials
long projections - large sa, thin surface (shorter path), lots of mitochondria
how does large sa help active transport
more space for transport proteins to be present
what is Mg needed for in plants
chlorophyll
what is N needed for in plants
to make protein (enzymes)
what is P needed for in plants
fruits and flowers
what is K needed for in plants
opening and closing stomata
how is the epithelium adapted for exchange of materials
lots of mitochondria, large sa, active transport proteins
why is active transport required to bring glucose into the body
starts with diffusion of glucose from lumen to epithelial cell- reaches equilibrium - diffusion stops - active transport starts to move remaining glucose (50%) into blood
why is active transport important in the absorption of food
allows the body to absorb as much digested food as possible
