movement of cells

Question 1

what are the characteristics of plasma membrane

Answer 1

semi-permeable

dynamic layer, transport protein , phospholipid bilayer

Question 2

what is a phospholipid bilayer

Answer 2

selective over hydrophobic and hydrophilic substances

Question 3

what substance can move through the plasma layer

Answer 3

non polar molecules like fatty acid, vitamin ADEK and oxygen

Question 4

what are the 2 ways substances can move in and out of membrane

Answer 4

active transport: against concentration with energy and protein
passive transport: movement down concentration w/o energy

Question 5

what are the 2 passive transport

Answer 5

diffusion and osmosis

Question 6

what is the meaning of diffusion

Answer 6

net movement of substances from region of higher concentration to lower concentration as a result of their random movement

Question 7

what are the 4 things to mention while explaining diffusion

Answer 7

net movement, result of random movement, down concentration gradient and no energy involved

Question 8

name 3 ways in which diffusion can help living organisms

Answer 8

obtain requirements
get rid of waste products
gas exchange for respiration

Question 9

examples of diffusion in living things

Answer 9

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

Question 10

what are the 6 factors that affect rate of diffusion

Answer 10

temperature, surface area, distanced moved, concentration gradient, size of particles and pressure

Question 11

what is osmosis

Answer 11

the diffusion of water molecules from an area of higher water potentials to low water potential through a semi-permeable membrane

Question 12

what is water potential

Answer 12

tendency of water molecules to leave the solution

Question 13

what is osmotic pressure

Answer 13

pressure needed to prevent water from moving into of the solution

Question 14

how to explain osmosis

Answer 14

state water potential
direction of movement
results of water movements
mention osmosis

Question 15

what happens to an animal cell when in higher water potential

Answer 15

cell will swell and burst

Question 16

what happens to an animal cell in lower water potential

Answer 16

the water will leave the cell causing the cell to shrivel and become crenated

Question 17

what is the meaning of lysis

Answer 17

happens when animal cell receives waters, swell and burst

Question 18

what do we say when a RBC lysis

Answer 18

haemolysed

Question 19

what does crenated mean

Answer 19

happens when animal cell lose water, shrivel up

Question 20

what happens to a plant cell is higher water potential

Answer 20

cell swell up, cytoplasm pushes against cell wall due to water pressure in vacuole ,cell becomes turgid - wont burst because of cell wall

Question 21

what happens to a plant cell when it is in low water potential

Answer 21

cell is plasmolysis as cytoplasm detaches frm cell wall . become flaccid and plant wilts

Question 22

what is turgid

Answer 22

condition of cell that is firm due to hydrostatic pressure in the vacuole pushing cytoplasm against the wall

Question 23

what is the meaning of flaccid

Answer 23

condition of cell that has lost water

Question 24

what is the meaning of plasmolysis

Answer 24

process where cell loses water causing the cytoplasm to detach frm the cell wall

Question 25

what is the meaning of deplasmolysed

Answer 25

condition of cell returning to turgidity after being plasmolysis

Question 26

what is the importance of osmosis in plants

Answer 26

maintains turgor pressure for support

uptake water frm roots to leaves

Question 27

what is the importance of osmosis in an animal cell

Answer 27

movement of water from one cell to another
absorption of water at large intestine
reabsorption of water at kidney tubes

Question 28

how does osmosis maintain turgor pressure in plant cells

Answer 28

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

Question 29

how does osmosis move water into animal cell

Answer 29

wp gradient exist between cell, water molecules will move frm higher wp to lower potential through cell membrane

Question 30

what is active transport

Answer 30

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

Question 31

name 3 ways in which active transport helps move substance across membrane

Answer 31

uptake of mineral by root hair cell

uptake of glucose by epithelial cells of villi and uptake of glucose by kidney tubes

Question 32

how does active transport uptake mineral by root hair

Answer 32

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

Question 33

how does active transport uptake glucose by epithelia cells of villi

Answer 33

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

Question 34

how does uptake of glucose by kidney tubes involve active transport

Answer 34

to avoid losing substances that are to be filtered in the kidney in the urine, they are reabsorbed into the bloodstream.