Honeydew httpwwwyoutubecomwatchvi6ovyj9ia2y it

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: – Phloem system under positive pressure aphid • Use of aphids Watch it! – "honeydew" http://www.youtube.com/watch?v=i6OVYj9Ia2Y it sticks and works to find the sieve element and sucks out Translocation Translocation Characteristics • Translocated substances – Xylem versus phloem Translocation Translocation Characteristics • Non-reducing sugars – Less reactive than reducing sugars • Have exposed aldehyde or ketone group – Specific and selective • Only certain non-reducing sugars are translocated Translocation Translocation Characteristics • Organic acids, proteins, mineral ions Translocation Translocation Characteristics • Rates of movement – 1 meter per hour • Gravity does not govern transport • Substances move from sources to sinks – Sources • Leaves, storage organs – Sinks • Meristems, rapidly growing organs – Leaves, roots, flowers, fruits, adventitious organs Translocation Diffusion vs Osmosis vs Mass flow • Diffusion is thermal motion of molecules equalizing differences in concentration of substance (i.e. a gradient in partial pressure) • Osmosis is thermal motion of solvent (water) equalizing effective differences in concentration of the solvent across a semipermeable membrane – The effective difference in concentration is formed by a solute (e.g. sucrose) diluting the solvent on one side of the semipermeable membrane • Mass flow is the movement of solute and solvent...
View Full Document

{[ snackBarMessage ]}

Ask a homework question - tutors are online