Water and Food Transport Video #2

Water Transport Root hairs absorb minerals via active transport. Glucose stored in roots produces energy via cellular respiration. Minerals pumped from epidermis → cortex → endodermis → xylem Sets up hypertonic condition → water rushes in via osmosis. Root pressure pushes minerals up the xylem. CR= cellular respiration

Water Transport Leaf Pull (Transpiration Pull) Evaporation of water “pulls” on adjacent water molecules.

Leaf Pull Theory Diagram Cohesion - when water molecules stick together by hydrogen bonds (water likes to stick to water) Adhesion - when water molecules stick to other materials (e.g./ the inside of a xylem tube)

* Movement from high pressure toward low pressure* Water Transport Bernoulli’s Principle Breeze blows by leaves creates low pressure. Water & minerals in roots in area of high pressure. * Movement from high pressure toward low pressure*

Food Transport Pressure-Flow Theory Sugar actively transported from leaves into phloem. Sets up hypertonic condition → water rushes in via osmosis. Creates area of high pressure with respect to roots. Phloem sap is pushed down and stored in roots.

Food Transport Companion cells Actively transports sugars into & out of sieve tubes *

Photosynthesis

Word & Chemical Equation Water + carbon dioxide → Glucose + oxygen 6 H2O + 6 CO2 → C6H12O6 + 6 O2

Overview Occurs in the chloroplast. Divided into two stages: Light Reactions. Calvin Cycle. Stroma – aquaous solution Thylakoid – organelle that contains chloroplasts. *

Light Reactions Takes place within thylakoid membrane. Uses solar energy to: Split water into hydrogen ions, electrons and oxygen. Excite electrons within chlorophyll that sets off a series of reactions that create high energy compounds.

Calvin Cycle Takes place within the stroma. Uses high energy compounds from light reactions to drive the cycle. Carbon dioxide combines with intermediate compounds to form glucose.

Photosynthesis NADPH – coenzyme used to help convert CO2 into glucose *