Cells - Transport across cell membranes - - Active Transport Flashcards Preview

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Flashcards in Cells - Transport across cell membranes - - Active Transport Deck (15)
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The movement of molecules or ions AGAINST a concentration gradient using ATP and carrier proteins is describing...

Active transport


Difference between active transport and facilitated diffusion

1. active transport uses ATP
2. Active transport uses only carriers (FD uses channels and carriers)
3. Active transport moves molecules against their concentration gradient


Differences between active transport and osmosis

1. Active transport moves solutes or ions osmosis water moves
2. Active transport uses a carrier to transport a molecule across the plasma membrane, osmosis water moves through the membrane directly


In active transport what does the molecule that is moving bind to on the carrier molecule?

A receptor/binding site


After the molecule has bound to the receptor on the carrier (in active transport), what happens next?

ATP binds to the carrier on the opposite side, it splits into ADP and Phosphate (P) (releasing energy) causing the carrier to change shape, allowing the entry of the molecule.


Why do some cells like root hair cells possess so many mitochondria?

Because they transport mineral ions against a concentration gradient. This requires energy


What is unique about the carrier proteins used in active transport?

they have a specific tertiary structure


Where is active transport used in humans?

Gut/Small intestine - absorption of glucose


How is low levels of glucose absorbed in the small intestine?

Using Na co transporter - ATP used indirectly


Which form of cell transport requires energy?

active transport


Which type of protein are involved in active transport?

carrier proteins


rate of active transport is affected by..

1. speed of carrier molecules
2. number of carrier molecules
3. rate of respiration - ATP availability


How does more carrier molecules affect active transport?

increases the rate


How does an inhibitor of respiration affect active transport?

Less or NO ATP produced to rate of active transport reduced


Where does the energy for active transport come from?

Hydrolysis of ATP (produced in respiration)

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