The water enters the xylem first by osmosis. Water moves from the soil to the root hair cell down a water potential gradient, and to the root cortex cell from a higher water potential to a lower water potential, this process will be repeated until water enters xylem. Because transpiration is occurring in the leaf, water is lost so there is a lower water potential inside the leaf. Osmosis moves water from the xylem to the leaf because the xylem has a higher water potential. Water moves from the xylem to the cells of the leaf. This pulls water up the xylem via cohesion which is the process of water molecules attracting each other and sticking together. Water does not fall down the xylem as here is adhesion which is the process of water molecules sticking to the inside of the xylem.
ALL (A, B, C, D) apples to the role of dna in protein synthesis
Answer:
F-actin is a double helical filament as opposed to G-actin,which is a globular protein .Each actin filament has two ends,called the plus and
the minus ends, which makes it recognizable from each other.This gives the structure a distinct polarity.
Explanation:
Actin is the most abundant protein that is found in almost all eukaryotic cells.Its a most important part cytoskeleton as its a monomeric subunits(size 42kDa) of two types of filaments i.e. microfilaments and thin filaments in cells. Actin is essentially required to maintain stability and morphogenesis of cell.It is involved in numerous significant processes such as endocytosis,cell division and migration.Actin is present in two forms:
•G-actin
•F-actin
The two forms of actin are different structurally.
G- actin is a globular shaped protein,usually present in free form(a monomer),having a tight binding site for another actin monomer.Each monomer has ATP. Upon polymerization of G-actin monomers, a polymer called F-actin filaments is form. This process is driven by hydrolysis of ATP.
