Transport In Cells Flashcards
Define “net”
Overall
Define concentration gradient
A measurement of how a concentration of a substance changes from one place to another
What are alveoli
Tiny air sacs found in the lungs through which gases exchange between blood and air
What are capillaries
Tiny blood vessels found between arteries and veins thag carry blood to organs and tissues
What’s ventilation
Breathing in(inhaling) and breathing out (exhaling)
What are villi (singular villus)
Tiny finger like projections that increase the surface area of the small intestine
What’s excretion
The removal of substances produced by chemical reactions inside cells from cell or organisms
What’s diffusion
The process where particles of gases or liquids spread out from an area with lots of them to an area where there is less
The net movement of particles from an area of high to low concentration
What are areas with lots of particles also known as
High concentration
What are areas with fewer particles also known as
Lower concentration
What kind of process is diffusion
A passive process so it happens naturally and no additional energy is needed
Where in a body in does diffusion occur
In cell membrane
Tell me how oxygen diffuses into lungs
We inhale high amounts of oxygen and as it enters alveoli it’s one tiny membrane from blood which has a lower concentration of oxygen so naturally it diffuses from alveoli to blood
What happens when oxygen enters blood stream
The blood is now high in oxygen and reaches out tissues and organs, the blood travels through capillaries and is only a membrane away from closest cells, the cells have a low concentration of oxygen due to using it for respiration to release energy from glucose so oxygen moves from blood to cells
Tell me how carbon dioxide diffuses
It goes in reverse direction as its produced in respiration it moves from Tissues and organs to blood and then to lungs through alveoli Which then we exhale
List some ways how the lungs are adapted for diffusion
Lungs have a large surface area so more oxygen can enter blood stream at once
Have moist membranes which allow substances to diffuse faster
Having thin lining (usually one cell layer thick)
Having a rich blood supply
Ventilation (breathing) supplies a regular fresh supply of air
Where in the body does diffusion also occur
The small intestine
How does glucose diffuse in small intestine
Small intestine has high concentration of glucose and it crosses from villi to blood which travels to tissues and organs which have lower concentration of glucose due to using it for respiration
Tell me about urea
Some cells make urea as a waste product which move from high to low concentration from blood to kidneys for excretion
How does oxygen diffuse in insects
Instead of lungs insects have spiracles where oxygen diffuses from tubes into cells for respiration
What is the maximum size of an insect partly determined by
The distance that oxygen can quickly diffuses into their cells
What’s different about insects and humanss about volume and surface area ratios
Insects have a greater surface area to volume ration than in large organisms such as humans
So we need exchange surfaces like alveoli and villi
How do fish diffuse oxygen
Fish absorbs oxygen through there gills by structures that have a large surface area, there are many finely divided sections added together which move oxygen to blood by diffusion
How does the concentration gradient affect diffusion
The steeper the gradient(bigger different in number of particles in a high and low area) means the more likely particles are to diffuses down the concentration gradient
How does temperature affect diffusion
Higher temps mean particles have more kinetic energy to they can move and spread faster
How does the surface area of membrane affect diffusion
Larger surface area means more particles can diffuse at once so make diffusion faster
What’s osmosis
the net diffusion of water from an area of high concentration of water to a lower concentration acros a partially permeable membrane
What’s partially permeable
Allowing substances only of a certain size through
What are stomata
Tiny holes in leaves bordered by guard cells this allow gases tk diffuse in and out
What do we say about energy in osmosis
It’s diffusion in water and it’s a passive process so no extra energy needed
We says it is down a concentration gradient
Tell me about osmosis in rain and soil
When is rain, the soil has a high concentration of water and it moves to plant root cells as its a lower concentration so water is osmosing into cells
Then water is carried up to leaves where most will evaporate through stomata holes (transpiration) so water wil always be carried up through roots and will always have a lower concentration
What does isotonic mean
When 2 solutions have the same concentration of water and solute so there’s no overall movement - water moves in both directions, we call the solutions isotonic
Give me an example of isotonic solutions
Red blood cells and our blood plasma are isotonic so water might osmosis out and into our red blood cells at same rate, likewise with plasma
What’s hypertonic
When one solution has a higher concentration than the other the higher concentration solution is called hypertonic
What’s hypotonic
Look it’s different to hypertonic!!
If one solution has a lower concentration than other the lower concentration solution is called hypotonic
What’s active transport
The net movement of particles from an area of LOW TO HIGh concentration using energy
What are mineral ions
Substances that are essential for healthy plant growth eg nitrates and magnesium
How does active transport use energy
Energy comes from respiration
Energy needed as we say particles move up (or against) a concentration gradient so it’s not a passive process
How do plants use active transport
They need to not only take water up through roots but mineral ions too, there’s a low concentration in soil but high in plants so need to use energy to get them
How do humans use active transport
Not having a sugary meal means the lining of the small intestine uses energy to move sugar from low to high concentration - from gut to blood