movement of cells Flashcards
what are the characteristics of plasma membrane
semi-permeable
dynamic layer, transport protein , phospholipid bilayer
what is a phospholipid bilayer
selective over hydrophobic and hydrophilic substances
what substance can move through the plasma layer
non polar molecules like fatty acid, vitamin ADEK and oxygen
what are the 2 ways substances can move in and out of membrane
active transport: against concentration with energy and protein
passive transport: movement down concentration w/o energy
what are the 2 passive transport
diffusion and osmosis
what is the meaning of diffusion
net movement of substances from region of higher concentration to lower concentration as a result of their random movement
what are the 4 things to mention while explaining diffusion
net movement, result of random movement, down concentration gradient and no energy involved
name 3 ways in which diffusion can help living organisms
obtain requirements
get rid of waste products
gas exchange for respiration
examples of diffusion in living things
co2 diffuse frm air to leaves - lower concentration of co2 in leaves
products of digestion are absorbed from ileum of mammals
water vapour through stomata
what are the 6 factors that affect rate of diffusion
temperature, surface area, distanced moved, concentration gradient, size of particles and pressure
what is osmosis
the diffusion of water molecules from an area of higher water potentials to low water potential through a semi-permeable membrane
what is water potential
tendency of water molecules to leave the solution
what is osmotic pressure
pressure needed to prevent water from moving into of the solution
how to explain osmosis
state water potential
direction of movement
results of water movements
mention osmosis
what happens to an animal cell when in higher water potential
cell will swell and burst
what happens to an animal cell in lower water potential
the water will leave the cell causing the cell to shrivel and become crenated
what is the meaning of lysis
happens when animal cell receives waters, swell and burst
what do we say when a RBC lysis
haemolysed
what does crenated mean
happens when animal cell lose water, shrivel up
what happens to a plant cell is higher water potential
cell swell up, cytoplasm pushes against cell wall due to water pressure in vacuole ,cell becomes turgid - wont burst because of cell wall
what happens to a plant cell when it is in low water potential
cell is plasmolysis as cytoplasm detaches frm cell wall . become flaccid and plant wilts
what is turgid
condition of cell that is firm due to hydrostatic pressure in the vacuole pushing cytoplasm against the wall
what is the meaning of flaccid
condition of cell that has lost water
what is the meaning of plasmolysis
process where cell loses water causing the cytoplasm to detach frm the cell wall
what is the meaning of deplasmolysed
condition of cell returning to turgidity after being plasmolysis
what is the importance of osmosis in plants
maintains turgor pressure for support
uptake water frm roots to leaves
what is the importance of osmosis in an animal cell
movement of water from one cell to another
absorption of water at large intestine
reabsorption of water at kidney tubes
how does osmosis maintain turgor pressure in plant cells
when cell lose water, wp in plant is lower compared to adjacent cell. water will move frm hwp and will fill up and vacuoles and push the cytoplasm towards cell wall. water pressure maintain shape making cell turgid
how does osmosis move water into animal cell
wp gradient exist between cell, water molecules will move frm higher wp to lower potential through cell membrane
what is active transport
movement of particles through the cell membrane from a region of lower concentration to a region of higher concentration using energy frm respiration with help of protein molecules
name 3 ways in which active transport helps move substance across membrane
uptake of mineral by root hair cell
uptake of glucose by epithelial cells of villi and uptake of glucose by kidney tubes
how does active transport uptake mineral by root hair
concentration of mineral in root hair is higher than soil
diffusion sometimes cant bring mineral frm soil into roots
rhc actively transport mineral salt frm soil into cell
how does active transport uptake glucose by epithelia cells of villi
glucose needs to be absorbed through the cell lining in intestine and into blood
alot of glucose wld pass out body in faeces if diffusion happen
glucose is absorbed in the intestine to a higher concentration in the cell lining the intestine
how does uptake of glucose by kidney tubes involve active transport
to avoid losing substances that are to be filtered in the kidney in the urine, they are reabsorbed into the bloodstream.
