4.1: Structure of the cell membrane

Question 1

All cells are surrounded by a

Answer 1

membrane

Question 2

In eukaryotic cells, many of the organelles are surrounded by a

Answer 2

membrane

Question 3

Partially permeable

Answer 3

Allow some molecules through but not others

Question 4

Membranes around organelle act as a …

dividing the cell into different …

Answer 4

barrier between organelles and the cytoplasm

compartments

Question 5

Cell membranes structure

Answer 5

fluid mosaic structure

Question 6

Cell membranes mainly composed of

Answer 6

lipids, proteins and carbohydrates

Question 7

Fluid mosaic model

describes

Answer 7

arrangement of molecules in the membrane

Question 8

Fluid mosaic model

in the model

Answer 8

Phospholipid molecules form a continuous double layer (bilayer) which is fluid

Question 9

Proteins on/in the bilayer

Answer 9

receptor proteins, channel proteins and carrier proteins

Question 10

Glycoproteins

Answer 10

proteins have a polysaccharide chain attached to them

Question 11

Glycolipids

Answer 11

lipids have a polysaccharide chain attached to them

Question 12

Centre of the phospholipid bilayer is

Answer 12

hydrophobic

Question 13

Cholesterol is a type of

Answer 13

lipid

Question 14

Where is cholesterol present in cells

Answer 14

all cell membrane except bacteria cell membranes

Question 15

Where is cholesterol present in cell membranes

Answer 15

between phospholipids

Question 16

Cholesterol function

Answer 16

makes the membrane more rigid and less fluid

Question 17

Cholesterol

how does it carry out its function

Answer 17

by fitting between phospholipids and binding to their hydrophobic tails which causes them to pack together more closely which restricts the movement of the phospholipids