Lecture 19 Resource Transport Flashcards
how do organisms transport materials within themselves
within and between cells
- > this can be over substancial distances
explain the different types of cellular transport
- Passive Transport
- > no energy; diffusion of solutes from [high] to [low], but includes co-transport - Active Transport
- > requires energy; moves solutes against [gradient]
which multicelluar level transport systems are used for short and long distances
Short distance: diffusion
- > through a few cell layers to supply adjacent cells
Long distance: transport systems
- > reduces dstance between exchange surfaces (i.e. gas, nutrients)
characteristics of animal circulatory systems
- > made up of fluid, vessels and pump(s)
- > pump uses energy to increase the pressure of the fluid (fluid flows from high P to low P)
- > connects aqueous environment of cells with organs that exchange gases, absorb nutrients, and eliminate waste
what are the two types of animal circulatory systems
- open circulatory system (interstitial fluid)
- closed circulatory system (blood)
characteristic of an open circulatory system
- > circulatory fluid bathes organs directly
- > heart(s) pumps fluid to sinuses
- > exchange between fluid and cells
- > hemolymph is also an interstitial fluid that contains hemocytes, proteins, and sugars
characteristics of a closed circulatory system
- > circulatory fluid confined to vessels
- > circulatory and intertitial fluid are separate
- > exchange between circulatory and intertitial fluid, and between intertitia fluid and cells
different types of animal blood circulation
- single circulation
- double circulation
explain a single circulation system
- > blood passes through heart once in circuit
- > oxygenated in gills, deoxygenated in body capillaries
- > through 2 capillary beds before returning to heart
explain a double circulation system
blood passes through two circuits, powered by two (combined) pumps
right side:
- > moves blood to pulmonary circuit where it is oxygenated in lung capillaries
left side:
- > moves blood to systemic capillaries where it is deoxygenated and binds to CO2
different types of double circulation
blood pressure and flow is influenced by ____________
blood vessel structure
- > endothelium cells line lumen of BV
- > elastic recoil of arterial walls air in maintaining P
- > flow influence by diameter of lumen (vasodil/con of smooth muscles in art.)
- > gravity important for the demands of blood pressure
what happens to the fluid that is lost in the process of gas exchange
lymph is returned to the blood via the lymphatic system (drained into large veins)
- > before lymph is drained, it is sent through lymph nodes which attack viruses and bacteria, filtering fluid
- > lymph nodes swell when immune response increases
water moves through plants by ____________
bulk flow
2 types of vascular tissue used in plant transport systems
- Xylem
- Phloem
Xylem
- > conducts water and minerals from root to shoots (1 direction, up)
- > dead at maturity (no membranse)
- > have thick secondary cell walls, hardended with linin which provides support and prevents colapse under water transport
phloem
- > transports sugar-water from site of production to site of need (source to sink)
- > sieve-tube elements alive at maturity, membrane is crucial to function
- > no nucleus, ribosomes, sometimes vacuole (provided by companion cell), allowing easy water flow
Explain water movement in plant transport systems
- > water moves from high to low potential energy
- > “water potential” (ψw) is measured in pressure (MPa)
- > potential energy is sum of solute and pressure potentials
ψW = ψS + ψP
What drives Xylem flow (transpiration)
- > solar energy
what drives phloem flow (translocation)
- > driven by metabolism; plant spends ATP to drive water movement
- loading sucrose lowers ψS so sieve tube takes up water by osmosis
- taking up water increase ψP, water flows down pressure gradient
- phloem is unloaded (also active step), and water is recycled to the associated xylem
