164 ^|

A Handbook of Biology

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Transport rate reaches a maximum when all the protein transporters are

being used or get saturated.

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The carrier protein is very specific. These are sensitive to inhibitors that

react with protein side chains.

(Odisha NEET 2020)

ÇØMPÅRÏSØÑ ØF DÏFFËRËÑT TRÅÑSPØRT PRØÇËSSËS

Property

Simple

diffusion

Facilitated

transport

Active

transport

Requires special membrane proteins

No

Yes

Yes

Highly selective

No

Yes

Yes

Transport saturates

No

Yes

Yes

Uphill transport

No

No

Yes

Requires ATP energy

No

No

Yes

PLÅÑT-WÅTËR RËLÅTÏØÑS

5

4

3

2

1

Water plays an important role in metabolic reactions.

Water is a universal solvent.

Protoplasm is mainly water in which different

molecules are dissolved and suspended.

Soft plant parts mostly contain water, e.g. watermelon

has 92% water.

Herbaceous plants have only 10 - 15% dry matter.