-
Prepare by Xtremepapers!
🚀 NEW from the xtremepape.rs team: AI exam prep — 120,000+ worked solutions, and it marks your handwritten working from a photo. Sign in with your forum account & try it free → prepare.xtremepape.rs
~AS Bio doubts Here !!~
- Thread starter nidzzz09
- Start date
- blood flowing into the lungs have higher partial pressure of CO2 and lower partial pressure of O2.
- alveoli is higher in partial pressure of O2 and lower in partial pressure of CO2.
- CO2 and oxygen moves down the concentration gradient.
- O2 diffuses into the moist surface of the alveoli then move across endothelium cells of the blood capillaries and into the blood.
- CO2 diffuses into across the blood capillaries and into the alveoli.
ps. do u even read your textbook? or even finish off your past years?
- alveoli is higher in partial pressure of O2 and lower in partial pressure of CO2.
- CO2 and oxygen moves down the concentration gradient.
- O2 diffuses into the moist surface of the alveoli then move across endothelium cells of the blood capillaries and into the blood.
- CO2 diffuses into across the blood capillaries and into the alveoli.
ps. do u even read your textbook? or even finish off your past years?
- Messages
- 138
- Reaction score
- 13
- Points
- 28
please someone answer this one..
how companion cells load sucrose into phloem sieve tubes?
how companion cells load sucrose into phloem sieve tubes?
- sucrose are loaded at the source into the companion cells.
- H+ ions are pumped out of the companion cells
- sucrose move into the companion cells through co-transporters
- sucrose move into the companion cells via active transport
- sucrose then move into the sieve tubes via the plasmodesmata between the sieve tubes and companion cells.
- sucrose diffuse down the concentration gradient into the sieve tubes.
- the low water potential in the sieve tubes then causes water to move by osmosis.
- the difference in hydrostatic pressure between source and sink causes mass flow to occur.
- sucrose is unloaded at the sink
so those are basically the points for the transport of sucrose. so from leaf ( source ) to companion cell, it is active transport, cause energy is needed to pump H+ ions out. then as the H+ ions have a higher concentration outside the companion cells, they then diffuses down the concentration gradient, back into the companion cells. AT THE SAME TIME, the sucrose move in together with the H+ ions into the companion cells. hence it is known as co-transport. then from companion cells to sieve tubes, is just diffusing across the plasmodesmata. simple
- H+ ions are pumped out of the companion cells
- sucrose move into the companion cells through co-transporters
- sucrose move into the companion cells via active transport
- sucrose then move into the sieve tubes via the plasmodesmata between the sieve tubes and companion cells.
- sucrose diffuse down the concentration gradient into the sieve tubes.
- the low water potential in the sieve tubes then causes water to move by osmosis.
- the difference in hydrostatic pressure between source and sink causes mass flow to occur.
- sucrose is unloaded at the sink
so those are basically the points for the transport of sucrose. so from leaf ( source ) to companion cell, it is active transport, cause energy is needed to pump H+ ions out. then as the H+ ions have a higher concentration outside the companion cells, they then diffuses down the concentration gradient, back into the companion cells. AT THE SAME TIME, the sucrose move in together with the H+ ions into the companion cells. hence it is known as co-transport. then from companion cells to sieve tubes, is just diffusing across the plasmodesmata. simple
- Messages
- 138
- Reaction score
- 13
- Points
- 28
thanks a lot, Xthegreat!
2 forms : triglyceride + phospholipids
triglyceride
- made up of glycerol + 3 fatty acids, form by condensation
- insoluble in water, but soluble in organic solvents
- non-polar, hydrophobic
- f(x) : storage for energy ( stores more energy than carbohydrate )
: as insulator against lost of heat
: to cushion organs
Phospholipids
- glycerol + phosphate + 2 fatty acids
- hydrophilic head, hydrophobic tails
- f(x) : forms the phospholipid bilayer of cell's plasma membrane
triglyceride
- made up of glycerol + 3 fatty acids, form by condensation
- insoluble in water, but soluble in organic solvents
- non-polar, hydrophobic
- f(x) : storage for energy ( stores more energy than carbohydrate )
: as insulator against lost of heat
: to cushion organs
Phospholipids
- glycerol + phosphate + 2 fatty acids
- hydrophilic head, hydrophobic tails
- f(x) : forms the phospholipid bilayer of cell's plasma membrane
- Messages
- 138
- Reaction score
- 13
- Points
- 28
oh so same process we have to write when asked about loading at source n unloading at sink?
Phagocytosis is the process by which bacteria are ingested by cells.
Describe the role of the cell surface membrane during phagocytosis
hw do i write an accurate answer for this
this wats written in ms
bacteria / antigen / epitope( antigenic determinant), combine(s) with / attach to/ recognition by, receptor ;
antibody on bacteria combines with receptor ;
opsonisation / opsonisation described ; e.g. facilitates phagocytosis
ref. to constant region ;
membrane infolds / invaginates / envelops / engulfs / enclose / AW ;
accept answers without ‘membrane’ where implied previously / later
membrane fuses ;
to form, vacuole / vesicle / phagosome (enclosing bacteria) ;
Describe the role of the cell surface membrane during phagocytosis
hw do i write an accurate answer for this
this wats written in ms
bacteria / antigen / epitope( antigenic determinant), combine(s) with / attach to/ recognition by, receptor ;
antibody on bacteria combines with receptor ;
opsonisation / opsonisation described ; e.g. facilitates phagocytosis
ref. to constant region ;
membrane infolds / invaginates / envelops / engulfs / enclose / AW ;
accept answers without ‘membrane’ where implied previously / later
membrane fuses ;
to form, vacuole / vesicle / phagosome (enclosing bacteria) ;