Membranes and movement

Created by: Jesshake01
Created on: 01-04-19 13:12

Suggest why the model of the membrane is described as a fluid mosaic.

Molecules within the membrane able to move; mixture of phospholipid and protein / arrangement of protein;

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Describe the structure of a phospholipid molecule and explain how phospholipids are arranged in a plasma membrane.

1 Phosholipid consists of glycerol; 2 (To which are joined) two fatty acids; 3 And phosphate; 4 By condensation/elimination of water molecules; 5 Arranged as bilayer in membrane; 6 Head/phosphate hydrophilic/polar and tail/fatty acid   hydrophobic/

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Describe the structure of a cell membrane. (5)

Double layer of phospholipid molecules; Detail of arrangement of phospholipids; Intrinsic proteins/protein molecules passing right through; Some with channels/pores; Extrinsic proteins/proteins only in one layer/on surface; Molecules can move in memb

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Describe the part played by cell surface membranes in regulating the movement of substances into and out of cells. (6)

Non-polar/lipid soluble molecules move through phospholipid layer/bilayer; Small molecules/water/gases move through phospholipid layer/bilayer; Ions/water soluble substances move through channels in proteins; Some proteins are gated; Reference to dif

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Explain how three features of a plasma membrane adapt it for its functions.

1. Phospholipid bilayer (as a barrier); 2. Forms a barrier to water soluble / charged substances / allows non-polar substances to pass OR Maintains a different environment on each side / compartmentalisation; 3. Bilayer is fluid; 4. Can bend to take

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Describe how the distribution of cell membranes in a prokaryotic cell such as a bacterium differs from that in a cell from a plant leaf. (4)

Absence of nuclear envelope/membrane; Membrane bounded organelles; Such as mitochondria/chloroplast/vacuole/lysosome; and membrane systems/endoplasmic reticulum/Golgi; Mesosomes in prokaryotes;

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Other cards in this set

Card 2

Front

Describe the structure of a phospholipid molecule and explain how phospholipids are arranged in a plasma membrane.

Back

Card 3

Front

Describe the structure of a cell membrane. (5)

Back

Card 4

Front

Describe the part played by cell surface membranes in regulating the movement of substances into and out of cells. (6)

Back

Card 5

Front

Explain how three features of a plasma membrane adapt it for its functions.

Back

View more cards

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Membranes and movement