Chapter 11 Water and organisms

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Chapter 11 Water and organisms
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Functions of kidney

• Regulate water content of bodyreabsorb a
  proportion of water when body is
  short of water.

larger

• Remove excess salt
• Excrete urea from deamination in liver.

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What conclusion can you draw?
Glucose is filtered from the blood in glomerulus,
but it is reabsorbed by the nephron.
Structure of nephron
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What conclusion can you draw?
All amino acids are filtered by ultrafiltration,
they are then reabsorbed by reabsorption in the
convoluted tubules.
Ultrafiltration vs. Reabsorption
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What conclusion can you draw?
Urea and salts are filtered in the Bowmans
capsule into glomerular filtrate. Their
concentration increases because water is
reabsorbed in the tubules.
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Small molecules, e.g., urea, glucose, salts
Glucose, salts diffuses in
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Renal artery
glomerulus
Bowmans capsule
Convoluted tubule
Renal vein
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ULTRAFILTRATION
glucose, amino acids, minerals, water, urea
REABSORPTION
glucose, amino acids, some water, some minerals
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Water and plants

• Turgor (??)
• when the cytoplasm of the plant cells swells,
• the cytoplasm pushes against the cell wall.
• Producing a hydrostatic pressure inside the
  cell.
• The cell become turgid.

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• Flaccid (???)
• when the cytoplasm of the plant cells shrink,
• the cytoplasm separate from the cell wall.
• The cell become flaccid.

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How plants lose water?

• By transpiration (????)
• water evaporates from mesophyll cells into the
  atmosphere.
• Through the stomata.
• This causes the pull of water from the mesophyll
  cells through xylem to the root, causing the
  absorption of water from soil
• gt transpiration pull (?????).

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What affect the rate of transpiration?

• Light causes the opening of stomata,
• thus increases the rate.
• High temperature increase the rate of
  evaporation,
• thus increases the rate.
• Low humidity in the atmosphere increases the
  concentration gradient between the intercellular
  air space and the atmosphere,
• thus increases the rate.
• High wind speed decreases the humidity,
• thus increases the rate.