exchange Flashcards
(22 cards)
Fitzroy river turtle adaptations
- inside rear opening two large sacs lined with finger like folds provide large surface area
fitzroy river turtle adaptations
muscular openings pumps water in and out ventilating folds and maintaining steep concentration
in animals
-having efficient blood supply moves diffusing substances away maintaining a steep concentration gradient
- Having a large surface area – increases site of exchange
-A membrane that is thin – provides a short diffusion pathway
in animals
ventilated makes gas exchange more efficient by maintaining a steep concentration gradient
what materials to organisms need to exchange
in oxygen ,out carbon ,
in water , out waste molecules ,
- in nutrients
What is the SA:V ratio for unicellular organisms?
Unicellular organisms have a relatively large SA:V ratio - allows sufficient transport of molecules into and out of the cell to meet the needs of the organism
When the surface area to volume ration is large, there is a lot of surface area for diffusion and not much volume to travel through
Therefore, organisms can get all the substances it needs by simple diffusion
In multicellular organisms, the surfaces and organ systems are specialised for exchanging materials. What does this allow?
It allows sufficient molecules to be transported into and out of cells for the organisms’ needs
how to do surface area to volume ratio
Divide the surface area by the volume. Therefore, if an organism has a surface area of 4 meters squared and a volume of 2 meters cubed, the Sa:Vol ratio is 2.
If the shape is a cube:
✅ Length of one side = L
Surface Area (SA) = 6 × (L × L) = 6L²
Volume (V) = L × L × L = L³
SA:V ratio = Surface Area ÷ Volume = 6L² ÷ L³ = 6 / L
👉 What factors make an exchange surface (like the lungs or root hairs) better at allowing substances (like oxygen or water) to diffuse?
gas exchange in humans
Gas exchange is the process of swapping oxygen (O₂) from the air with carbon dioxide (CO₂) from the blood. This happens in the lungs at tiny air sacs called alveoli.
Alveoli adaptations for gas exchange:
Large surface area: Many alveoli increase the area for exchange.
Thin walls (one cell thick): Short distance for diffusion.
Moist lining: Gases dissolve easily for diffusion.
Rich blood supply: Capillaries surround alveoli to carry gases to and from the lungs.
adaptations of Villus (plural: villi) in the small intestine:
✅ Large surface area:
There are millions of villi, increasing the total surface area for absorption.
✅ Thin walls (one cell thick):
This means a short distance for nutrients to diffuse into the blood quickly.
✅ Rich blood supply (capillary network):
Each villus has a network of blood capillaries to carry away absorbed nutrients and keep the concentration gradient steep (so diffusion can happen fast).
function of villus in small intestine
The villi in the small intestine are responsible for absorbing the products of digestion — nutrients from food — into the bloodstream and lymphatic system.
Function of plant roots:
The primary function (most important job) of the roots is to take in water and nutrients
What substances are exchanged in plant roots?
Taken in by the roots:
Water: absorbed by osmosis from the soil into root hair cells.
Mineral ions (nutrients): such as nitrates, phosphates, potassium, magnesium, etc., absorbed by active transport or diffusion.
🌱 Released by the roots:
In some cases, small amounts of gases like carbon dioxide (CO₂) can diffuse out during respiration in root cells (not as significant as the absorption though).
adaptations of gills for gas exchange
Large surface area: gill filaments and lamellae increase surface area for gas exchange.
Thin walls: one cell thick for short diffusion distance.
Rich blood supply: maintains a concentration gradient for diffusion.
Counter-current flow: blood flows in the opposite direction to water flow, maximizing oxygen absorption.
gas exchange in fish
Fish take in oxygen dissolved in water and release carbon dioxide from their blood into the water.
why might gas exchange be harder for fish than animals
- concentration of oxygen in water is dependent on the temperature of the water.
-The concentration of oxygen in water is only around 1% at 15°C.
-This compares with 21% in the air at any temperature. The efficiency of gills has to be - and is - very high - 70 to 80% of the available oxygen is extracted from the water.
Adaptations for exchanging materials of plant roots:
-have large surface area - made even bigger by root hair cells to make uptake of water and minerals more efficient
-Root hair cells contain lots of mitochondria to produce the energy (ATP) needed for active transport even though mineral ions are in low concentration in the soil, active transport lets the plant take them up against the gradient — this ensures the plant gets enough essential nutrients.
-The xylem vessels form continuous tubes that carry water and mineral ions from the roots to the leaves efficiently.
-Lignin in xylem walls strengthens them and prevents collapse during transport
-The thin walls of root hair cells provide a short distance for osmosis.
-The cytoplasm of the root hair cell has a higher solute concentration, so water easily moves from the soil (high water concentration) into the cell (lower water concentration)..
- water constantly moves away from the transpiration stream maintaining a steep concentration gradient.
plant leaves function-
They are broad and flat to provide a large surface area to absorb more sunlight.
They contain lots of chloroplasts with chlorophyll to trap light energy.
The palisade layer is packed with chloroplasts and is near the upper surface to capture maximum light.
Where can the process of exchange only take place?
across its surface
What does the amount of material which needs to be exchanged depend on
Its volume
What does every living organism need to do
Exchange materials with its surroundings
