4.1: The structure of the cell surface membrane Flashcards

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1
Q

All membranes around and within all cells (including the membranes around and within cell organelles) have the same what?

A

All membranes:
1. Around
2. Within
all cells (including the membranes around and within cell organelles) have the same basic structure

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2
Q

All membranes around and within all cells (including the membranes around and within cell organelles) have the same basic structure and are known as what?

A

All membranes around and within all cells (including the membranes around and within cell organelles):

  1. Have the same basic structure
  2. Are known as plasma membranes
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3
Q

All membranes around and within all cells (including the membranes around and within cell organelles) have the same basic structure and are known as plasma membranes.
The cell-surface membrane is the name specifically given to the plasma membrane that does what?

A

The cell-surface membrane is the name specifically given to the plasma membrane that:

  1. Surrounds cells
  2. Forms the boundary between the cell cytoplasm and the environment
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4
Q

All membranes around and within all cells (including the membranes around and within cell organelles) have the same basic structure and are known as plasma membranes.
The cell-surface membrane is the name specifically given to the plasma membrane that surrounds cells and forms the boundary between the cell cytoplasm and the environment.
It allows what to be established inside and outside a cell?

A

The cell-surface membrane allows different conditions to be established:
1. Inside
2. Outside
a cell

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5
Q

All membranes around and within all cells (including the membranes around and within cell organelles) have the same basic structure and are known as plasma membranes.
The cell-surface membrane is the name specifically given to the plasma membrane that surrounds cells and forms the boundary between the cell cytoplasm and the environment.
It allows different conditions to be established inside and outside a cell.
It controls the what in and out of the cell?

A

The cell-surface membrane controls the movement of substances:
1. In
2. Out
of the cell

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6
Q

All membranes around and within all cells (including the membranes around and within cell organelles) have the same basic structure and are known as plasma membranes.
The cell-surface membrane is the name specifically given to the plasma membrane that surrounds cells and forms the boundary between the cell cytoplasm and the environment.
It allows different conditions to be established inside and outside a cell.
It controls the movement of substances in and out of the cell.
What are the molecules that form the structure of cell-surface membranes?

A

The molecules that form the structure of cell-surface membranes are:

  1. Phospholipids
  2. Proteins
  3. Cholesterol
  4. Glycolipids
  5. Glycoproteins
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7
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Phospholipids form a what?

A

Phospholipids form a bilayer

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8
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Phospholipids form a bilayer.
Phospholipids are important components of cell-surface membranes for the following reasons:
1. The hydrophilic what of both phospholipid layers point to what?

A

The hydrophilic heads of both phospholipid layers point to the outside of the cell-surface membrane

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9
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Phospholipids form a bilayer.
Phospholipids are important components of cell-surface membranes for the following reasons:
1. The hydrophilic heads of both phospholipid layers point to the outside of the cell-surface membrane, what on both sides?

A

The hydrophilic heads of both phospholipid layers point to the outside of the cell-surface membrane, attracted by water on both sides

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10
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Phospholipids form a bilayer.
Phospholipids are important components of cell-surface membranes for the following reasons:
1. The hydrophilic heads of both phospholipid layers point to the outside of the cell-surface membrane, attracted by water on both sides.
2. The hydrophobic what of both phospholipid layers point into what?

A

The hydrophobic tails of both phospholipid layers point into the centre of the cell membrane

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11
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Phospholipids form a bilayer.
Phospholipids are important components of cell-surface membranes for the following reasons:
1. The hydrophilic heads of both phospholipid layers point to the outside of the cell-surface membrane, attracted by water on both sides.
2. The hydrophobic tails of both phospholipid layers point into the centre of the cell membrane, what on both sides?

A

The hydrophobic tails of both phospholipid layers point into the centre of the cell membrane, repelled by the water on both sides

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12
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Phospholipids form a bilayer.
Phospholipids are important components of cell-surface membranes for the following reasons:
1. The hydrophilic heads of both phospholipid layers point to the outside of the cell-surface membrane, attracted by water on both sides.
2. The hydrophobic tails of both phospholipid layers point into the centre of the cell membrane, repelled by the water on both sides.
What moves through the membrane?

A

Lipid-soluble material moves through the membrane

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13
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Phospholipids form a bilayer.
Phospholipids are important components of cell-surface membranes for the following reasons:
1. The hydrophilic heads of both phospholipid layers point to the outside of the cell-surface membrane, attracted by water on both sides.
2. The hydrophobic tails of both phospholipid layers point into the centre of the cell membrane, repelled by the water on both sides.
Lipid-soluble material moves through the membrane via what?

A

Lipid-soluble material moves through the membrane via the phospholipid bilayer

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14
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Phospholipids form a bilayer.
Phospholipids are important components of cell-surface membranes for the following reasons:
1. The hydrophilic heads of both phospholipid layers point to the outside of the cell-surface membrane, attracted by water on both sides.
2. The hydrophobic tails of both phospholipid layers point into the centre of the cell membrane, repelled by the water on both sides.
Lipid-soluble material moves through the membrane via the phospholipid bilayer.
The functions of phospholipids in the membrane are to:
1. Allow what?

A

The functions of phospholipids in the membrane are to allow lipid-soluble substances to:
1. Enter
2. Leave
the cell

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15
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Phospholipids form a bilayer.
Phospholipids are important components of cell-surface membranes for the following reasons:
1. The hydrophilic heads of both phospholipid layers point to the outside of the cell-surface membrane, attracted by water on both sides.
2. The hydrophobic tails of both phospholipid layers point into the centre of the cell membrane, repelled by the water on both sides.
Lipid-soluble material moves through the membrane via the phospholipid bilayer.
The functions of phospholipids in the membrane are to:
1. Allow lipid-soluble substances to enter and leave the cell.
2. Prevent what?

A

The functions of phospholipids in the membrane are to prevent water-soluble substances:
1. Entering
2. Leaving
the cell

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16
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Phospholipids form a bilayer.
Phospholipids are important components of cell-surface membranes for the following reasons:
1. The hydrophilic heads of both phospholipid layers point to the outside of the cell-surface membrane, attracted by water on both sides.
2. The hydrophobic tails of both phospholipid layers point into the centre of the cell membrane, repelled by the water on both sides.
Lipid-soluble material moves through the membrane via the phospholipid bilayer.
The functions of phospholipids in the membrane are to:
1. Allow lipid-soluble substances to enter and leave the cell.
2. Prevent water-soluble substances entering and leaving the cell.
3. Make the membrane what?

A

The functions of phospholipids in the membrane are to make the membrane:

  1. Flexible
  2. Self-sealing
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17
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Proteins are what throughout the cell surface membrane?

A

Proteins are interspersed throughout the cell surface membrane

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18
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Proteins are interspersed throughout the cell surface membrane.
Proteins are embedded in the phospholipid bilayer in 2 main ways:
1. Some proteins occur where?

A

Some proteins occur in the surface of the phospholipid bilayer

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19
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Proteins are interspersed throughout the cell surface membrane.
Proteins are embedded in the phospholipid bilayer in 2 main ways:
1. Some proteins occur in the surface of the phospholipid bilayer and never do what?

A

Some proteins:

  1. Occur in the surface of the phospholipid bilayer
  2. Never extend completely across it
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20
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Proteins are interspersed throughout the cell surface membrane.
Proteins are embedded in the phospholipid bilayer in 2 main ways:
1. Some proteins occur in the surface of the phospholipid bilayer and never extend completely across it.
They act either to do what or, in conjunction with glycolipids, as what?

A

They act either:
1. To give mechanical support to the membrane
Or,
2. In conjunction with glycolipids, as cell receptors

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21
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Proteins are interspersed throughout the cell surface membrane.
Proteins are embedded in the phospholipid bilayer in 2 main ways:
1. Some proteins occur in the surface of the phospholipid bilayer and never extend completely across it.
They act either to give mechanical support to the membrane or, in conjunction with glycolipids, as cell receptors for what?

A

They act either:
1. To give mechanical support to the membrane
Or,
2. In conjunction with glycolipids, as cell receptors for molecules such as hormones

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22
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Proteins are interspersed throughout the cell surface membrane.
Proteins are embedded in the phospholipid bilayer in 2 main ways:
1. Some proteins occur in the surface of the phospholipid bilayer and never extend completely across it.
They act either to give mechanical support to the membrane or, in conjunction with glycolipids, as cell receptors for molecules such as hormones.
2. Other proteins completely do what?

A

Other proteins completely span the phospholipid bilayer

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23
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Proteins are interspersed throughout the cell surface membrane.
Proteins are embedded in the phospholipid bilayer in 2 main ways:
1. Some proteins occur in the surface of the phospholipid bilayer and never extend completely across it.
They act either to give mechanical support to the membrane or, in conjunction with glycolipids, as cell receptors for molecules such as hormones.
2. Other proteins completely span the phospholipid bilayer from what?

A

Other proteins completely span the phospholipid bilayer from:
1. One side
to
2. The other

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24
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Proteins are interspersed throughout the cell surface membrane.
Proteins are embedded in the phospholipid bilayer in 2 main ways:
1. Some proteins occur in the surface of the phospholipid bilayer and never extend completely across it.
They act either to give mechanical support to the membrane or, in conjunction with glycolipids, as cell receptors for molecules such as hormones.
2. Other proteins completely span the phospholipid bilayer from one side to the other.
Some proteins are protein channels.
What do protein channels do?

A

Protein channels form water-filled tubes to allow water-soluble ions to diffuse across the membrane

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25
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Proteins are interspersed throughout the cell surface membrane.
Proteins are embedded in the phospholipid bilayer in 2 main ways:
1. Some proteins occur in the surface of the phospholipid bilayer and never extend completely across it.
They act either to give mechanical support to the membrane or, in conjunction with glycolipids, as cell receptors for molecules such as hormones.
2. Other proteins completely span the phospholipid bilayer from one side to the other.
Some proteins are protein channels.
Protein channels form water-filled tubes to allow water-soluble ions to diffuse across the membrane.
Other proteins are what?

A

Other proteins are carrier proteins

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26
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Proteins are interspersed throughout the cell surface membrane.
Proteins are embedded in the phospholipid bilayer in 2 main ways:
1. Some proteins occur in the surface of the phospholipid bilayer and never extend completely across it.
They act either to give mechanical support to the membrane or, in conjunction with glycolipids, as cell receptors for molecules such as hormones.
2. Other proteins completely span the phospholipid bilayer from one side to the other.
Some proteins are protein channels.
Protein channels form water-filled tubes to allow water-soluble ions to diffuse across the membrane.
Other proteins are carrier proteins that do what?

A

Other proteins are carrier proteins that:

  1. Bind to ions or molecules like glucose and amino acids
  2. Then change shape in order to move these molecules across the membrane
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27
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Proteins are interspersed throughout the cell surface membrane.
Proteins are embedded in the phospholipid bilayer in 2 main ways:
1. Some proteins occur in the surface of the phospholipid bilayer and never extend completely across it.
They act either to give mechanical support to the membrane or, in conjunction with glycolipids, as cell receptors for molecules such as hormones.
2. Other proteins completely span the phospholipid bilayer from one side to the other.
Some proteins are protein channels.
Protein channels form water-filled tubes to allow water-soluble ions to diffuse across the membrane.
Other proteins are carrier proteins that bind to ions or molecules like glucose and amino acids and then change shape in order to move these molecules across the membrane.
The functions of the proteins in the membrane are to:
1. Provide what?

A

The functions of the proteins in the membrane are to provide structural support

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28
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Proteins are interspersed throughout the cell surface membrane.
Proteins are embedded in the phospholipid bilayer in 2 main ways:
1. Some proteins occur in the surface of the phospholipid bilayer and never extend completely across it.
They act either to give mechanical support to the membrane or, in conjunction with glycolipids, as cell receptors for molecules such as hormones.
2. Other proteins completely span the phospholipid bilayer from one side to the other.
Some proteins are protein channels.
Protein channels form water-filled tubes to allow water-soluble ions to diffuse across the membrane.
Other proteins are carrier proteins that bind to ions or molecules like glucose and amino acids and then change shape in order to move these molecules across the membrane.
The functions of the proteins in the membrane are to:
1. Provide structural support.
2. Act as channels, doing what?

A

The functions of the proteins in the membrane are to act as channels, transporting water-soluble substances across the membrane

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29
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Proteins are interspersed throughout the cell surface membrane.
Proteins are embedded in the phospholipid bilayer in 2 main ways:
1. Some proteins occur in the surface of the phospholipid bilayer and never extend completely across it.
They act either to give mechanical support to the membrane or, in conjunction with glycolipids, as cell receptors for molecules such as hormones.
2. Other proteins completely span the phospholipid bilayer from one side to the other.
Some proteins are protein channels.
Protein channels form water-filled tubes to allow water-soluble ions to diffuse across the membrane.
Other proteins are carrier proteins that bind to ions or molecules like glucose and amino acids and then change shape in order to move these molecules across the membrane.
The functions of the proteins in the membrane are to:
1. Provide structural support.
2. Act as channels, transporting water-soluble substances across the membrane.
3. Allow what through carrier proteins?

A

The functions of the proteins in the membrane are to allow active transport across the membrane through carrier proteins

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30
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Proteins are interspersed throughout the cell surface membrane.
Proteins are embedded in the phospholipid bilayer in 2 main ways:
1. Some proteins occur in the surface of the phospholipid bilayer and never extend completely across it.
They act either to give mechanical support to the membrane or, in conjunction with glycolipids, as cell receptors for molecules such as hormones.
2. Other proteins completely span the phospholipid bilayer from one side to the other.
Some proteins are protein channels.
Protein channels form water-filled tubes to allow water-soluble ions to diffuse across the membrane.
Other proteins are carrier proteins that bind to ions or molecules like glucose and amino acids and then change shape in order to move these molecules across the membrane.
The functions of the proteins in the membrane are to:
1. Provide structural support.
2. Act as channels, transporting water-soluble substances across the membrane.
3. Allow active transport across the membrane through carrier proteins.
4. Form what?

A

The functions of the proteins in the membrane are to form cell-surface receptors

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31
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Proteins are interspersed throughout the cell surface membrane.
Proteins are embedded in the phospholipid bilayer in 2 main ways:
1. Some proteins occur in the surface of the phospholipid bilayer and never extend completely across it.
They act either to give mechanical support to the membrane or, in conjunction with glycolipids, as cell receptors for molecules such as hormones.
2. Other proteins completely span the phospholipid bilayer from one side to the other.
Some proteins are protein channels.
Protein channels form water-filled tubes to allow water-soluble ions to diffuse across the membrane.
Other proteins are carrier proteins that bind to ions or molecules like glucose and amino acids and then change shape in order to move these molecules across the membrane.
The functions of the proteins in the membrane are to:
1. Provide structural support.
2. Act as channels, transporting water-soluble substances across the membrane.
3. Allow active transport across the membrane through carrier proteins.
4. Form cell-surface receptors for doing what?

A

The functions of the proteins in the membrane are to form cell-surface receptors for identifying cells

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32
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Proteins are interspersed throughout the cell surface membrane.
Proteins are embedded in the phospholipid bilayer in 2 main ways:
1. Some proteins occur in the surface of the phospholipid bilayer and never extend completely across it.
They act either to give mechanical support to the membrane or, in conjunction with glycolipids, as cell receptors for molecules such as hormones.
2. Other proteins completely span the phospholipid bilayer from one side to the other.
Some proteins are protein channels.
Protein channels form water-filled tubes to allow water-soluble ions to diffuse across the membrane.
Other proteins are carrier proteins that bind to ions or molecules like glucose and amino acids and then change shape in order to move these molecules across the membrane.
The functions of the proteins in the membrane are to:
1. Provide structural support.
2. Act as channels, transporting water-soluble substances across the membrane.
3. Allow active transport across the membrane through carrier proteins.
4. Form cell-surface receptors for identifying cells.
5. Help cells do what?

A

The functions of the proteins in the membrane are to help cells adhere together

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33
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Proteins are interspersed throughout the cell surface membrane.
Proteins are embedded in the phospholipid bilayer in 2 main ways:
1. Some proteins occur in the surface of the phospholipid bilayer and never extend completely across it.
They act either to give mechanical support to the membrane or, in conjunction with glycolipids, as cell receptors for molecules such as hormones.
2. Other proteins completely span the phospholipid bilayer from one side to the other.
Some proteins are protein channels.
Protein channels form water-filled tubes to allow water-soluble ions to diffuse across the membrane.
Other proteins are carrier proteins that bind to ions or molecules like glucose and amino acids and then change shape in order to move these molecules across the membrane.
The functions of the proteins in the membrane are to:
1. Provide structural support.
2. Act as channels, transporting water-soluble substances across the membrane.
3. Allow active transport across the membrane through carrier proteins.
4. Form cell-surface receptors for identifying cells.
5. Help cells adhere together.
6. Act as what?

A

The functions of the proteins in the membrane are to act as receptors

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34
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Proteins are interspersed throughout the cell surface membrane.
Proteins are embedded in the phospholipid bilayer in 2 main ways:
1. Some proteins occur in the surface of the phospholipid bilayer and never extend completely across it.
They act either to give mechanical support to the membrane or, in conjunction with glycolipids, as cell receptors for molecules such as hormones.
2. Other proteins completely span the phospholipid bilayer from one side to the other.
Some proteins are protein channels.
Protein channels form water-filled tubes to allow water-soluble ions to diffuse across the membrane.
Other proteins are carrier proteins that bind to ions or molecules like glucose and amino acids and then change shape in order to move these molecules across the membrane.
The functions of the proteins in the membrane are to:
1. Provide structural support.
2. Act as channels, transporting water-soluble substances across the membrane.
3. Allow active transport across the membrane through carrier proteins.
4. Form cell-surface receptors for identifying cells.
5. Help cells adhere together.
6. Act as receptors, for example for what?

A

The functions of the proteins in the membrane are to act as receptors, for example for hormones

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35
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Cholesterol molecules occur where?

A

Cholesterol molecules occur within the phospholipid bilayer of the cell-surface membrane

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36
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Cholesterol molecules occur within the phospholipid bilayer of the cell-surface membrane.
They do what?

A

The cholesterol molecules add strength to the membranes

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37
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Cholesterol molecules occur within the phospholipid bilayer of the cell-surface membrane.
They add strength to the membranes.
Cholesterol molecules are very what?

A

Cholesterol molecules are very hydrophobic

38
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Cholesterol molecules occur within the phospholipid bilayer of the cell-surface membrane.
They add strength to the membranes.
Cholesterol molecules are very hydrophobic and therefore play an important role in preventing what?

A

Cholesterol molecules are very hydrophobic and therefore play an important role in preventing the loss of:
1. Water
2. Dissolved ions
from the cell

39
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Cholesterol molecules occur within the phospholipid bilayer of the cell-surface membrane.
They add strength to the membranes.
Cholesterol molecules are very hydrophobic and therefore play an important role in preventing the loss of water and dissolved ions from the cell.
The cholesterol molecules also pull together what?

A

The cholesterol molecules also pull together the fatty acid tails of the phospholipid molecules

40
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Cholesterol molecules occur within the phospholipid bilayer of the cell-surface membrane.
They add strength to the membranes.
Cholesterol molecules are very hydrophobic and therefore play an important role in preventing the loss of water and dissolved ions from the cell.
The cholesterol molecules also pull together the fatty acid tails of the phospholipid molecules, doing what?

A

The cholesterol molecules also pull together the fatty acid tails of the phospholipid molecules:
1. Limiting their movement and that of other molecules
,but
2. Without making the membrane as a whole too rigid

41
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Cholesterol molecules occur within the phospholipid bilayer of the cell-surface membrane.
They add strength to the membranes.
Cholesterol molecules are very hydrophobic and therefore play an important role in preventing the loss of water and dissolved ions from the cell.
The cholesterol molecules also pull together the fatty acid tails of the phospholipid molecules, limiting their movement and that of other molecules, but without making the membrane as a whole too rigid.
The functions of cholesterol in the membrane are to:
1. Reduce what?

A

The functions of cholesterol in the membrane are to reduce lateral movement of other molecules

42
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Cholesterol molecules occur within the phospholipid bilayer of the cell-surface membrane.
They add strength to the membranes.
Cholesterol molecules are very hydrophobic and therefore play an important role in preventing the loss of water and dissolved ions from the cell.
The cholesterol molecules also pull together the fatty acid tails of the phospholipid molecules, limiting their movement and that of other molecules, but without making the membrane as a whole too rigid.
The functions of cholesterol in the membrane are to:
1. Reduce lateral movement of other molecules, including what?

A

The functions of cholesterol in the membrane are to reduce lateral movement of other molecules, including phospholipids

43
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Cholesterol molecules occur within the phospholipid bilayer of the cell-surface membrane.
They add strength to the membranes.
Cholesterol molecules are very hydrophobic and therefore play an important role in preventing the loss of water and dissolved ions from the cell.
The cholesterol molecules also pull together the fatty acid tails of the phospholipid molecules, limiting their movement and that of other molecules, but without making the membrane as a whole too rigid.
The functions of cholesterol in the membrane are to:
1. Reduce lateral movement of other molecules, including phospholipids.
2. Make the membrane what?

A

The functions of cholesterol in the membrane are to make the membrane less fluid at high temperatures

44
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Cholesterol molecules occur within the phospholipid bilayer of the cell-surface membrane.
They add strength to the membranes.
Cholesterol molecules are very hydrophobic and therefore play an important role in preventing the loss of water and dissolved ions from the cell.
The cholesterol molecules also pull together the fatty acid tails of the phospholipid molecules, limiting their movement and that of other molecules, but without making the membrane as a whole too rigid.
The functions of cholesterol in the membrane are to:
1. Reduce lateral movement of other molecules, including phospholipids.
2. Make the membrane less fluid at high temperatures.
3. Prevent what from the cell?

A

The functions of cholesterol in the membrane are to prevent leakage of:
1. Water
2. Dissolved ions
from the cell

45
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Glycolipids are made up of what?

A

Glycolipids are made up of a:
1. Carbohydrate
covalently bonded with
2. Lipid

46
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Glycolipids are made up of a carbohydrate covalently bonded with a lipid.
What does the carbohydrate portion of the glycolipids do?

A

The carbohydrate portion of the glycolipids extends from the:
1. Phospholipid bilayer
into
2. Watery environment outside the cell

47
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Glycolipids are made up of a carbohydrate covalently bonded with a lipid.
The carbohydrate portion of the glycolipids extends from the phospholipid bilayer into the watery environment outside the cell, where it acts as a what?

A

The carbohydrate portion of the glycolipids extends from the:
1. Phospholipid bilayer
into
2. Watery environment outside the cell
,where it acts as a cell-surface receptor

48
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Glycolipids are made up of a carbohydrate covalently bonded with a lipid.
The carbohydrate portion of the glycolipids extends from the phospholipid bilayer into the watery environment outside the cell, where it acts as a cell-surface receptor for what?

A

The carbohydrate portion of the glycolipids extends from the:
1. Phospholipid bilayer
into
2. Watery environment outside the cell
,where it acts as a cell-surface receptor for specific chemicals

49
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Glycolipids are made up of a carbohydrate covalently bonded with a lipid.
The carbohydrate portion of the glycolipids extends from the phospholipid bilayer into the watery environment outside the cell, where it acts as a cell-surface receptor for specific chemicals.
Example

A

For example, the human ABO blood system operates as a result of glycolipids on the cell-surface membrane

50
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Glycolipids are made up of a carbohydrate covalently bonded with a lipid.
The carbohydrate portion of the glycolipids extends from the phospholipid bilayer into the watery environment outside the cell, where it acts as a cell-surface receptor for specific chemicals.
The functions of glycolipids in the membrane are to:
1. Act as what?

A

The functions of glycolipids in the membrane are to act as recognition sites

51
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Glycolipids are made up of a carbohydrate covalently bonded with a lipid.
The carbohydrate portion of the glycolipids extends from the phospholipid bilayer into the watery environment outside the cell, where it acts as a cell-surface receptor for specific chemicals.
The functions of glycolipids in the membrane are to:
1. Act as recognition sites.
2. Help maintain what?

A

The functions of glycolipids in the membrane are to help maintain the stability of the membrane

52
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Glycolipids are made up of a carbohydrate covalently bonded with a lipid.
The carbohydrate portion of the glycolipids extends from the phospholipid bilayer into the watery environment outside the cell, where it acts as a cell-surface receptor for specific chemicals.
The functions of glycolipids in the membrane are to:
1. Act as recognition sites.
2. Help maintain the stability of the membrane.
3. Help cells to do what?

A

The functions of glycolipids in the membrane are to:

  1. Help cells to attach to one another
  2. So form tissues
53
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Carbohydrate chains are attached to many what?

A

Carbohydrate chains are attached to many extrinsic proteins

54
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Carbohydrate chains are attached to many extrinsic proteins where?

A

Carbohydrate chains are attached to many extrinsic proteins on the outer surface of the cell membrane

55
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Carbohydrate chains are attached to many extrinsic proteins on the outer surface of the cell membrane.
These glycoproteins also act as what?

A

These glycoproteins also act as cell-surface receptors

56
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Carbohydrate chains are attached to many extrinsic proteins on the outer surface of the cell membrane.
These glycoproteins also act as cell-surface receptors, more specifically for what?

A

These glycoproteins also act as cell-surface receptors, more specifically for:

  1. Hormones
  2. Neurotransmitters
57
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Carbohydrate chains are attached to many extrinsic proteins on the outer surface of the cell membrane.
These glycoproteins also act as cell-surface receptors, more specifically for hormones and neurotransmitters.
The functions of glycoproteins in the membrane are to:
1. Act as what?

A

The functions of glycoproteins in the membrane are to act as recognition sites

58
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Carbohydrate chains are attached to many extrinsic proteins on the outer surface of the cell membrane.
These glycoproteins also act as cell-surface receptors, more specifically for hormones and neurotransmitters.
The functions of glycoproteins in the membrane are to:
1. Act as recognition sites.
2. Help cells to do what?

A

The functions of glycoproteins in the membrane are to help cells to:

  1. Attach to one another
  2. So form tissues
59
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Carbohydrate chains are attached to many extrinsic proteins on the outer surface of the cell membrane.
These glycoproteins also act as cell-surface receptors, more specifically for hormones and neurotransmitters.
The functions of glycoproteins in the membrane are to:
1. Act as recognition sites.
2. Help cells to attach to one another and so form tissues.
3. Allow cells to do what?

A

The functions of glycoproteins in the membrane are to allow cells to recognise one another

60
Q

The molecules that form the structure of cell-surface membranes are phospholipids, proteins, cholesterol, glycolipids and glycoproteins.
Carbohydrate chains are attached to many extrinsic proteins on the outer surface of the cell membrane.
These glycoproteins also act as cell-surface receptors, more specifically for hormones and neurotransmitters.
The functions of glycoproteins in the membrane are to:
1. Act as recognition sites.
2. Help cells to attach to one another and so form tissues.
3. Allow cells to recognise one another.
Example

A

For example, lymphocytes can recognise an organism’s own cells

61
Q

The functions of membranes within cells are to:

1. Control the entry and exit of materials in what organelles?

A

The functions of membranes within cells are to control the:
1. Entry
2. Exit
of materials in discrete organelles

62
Q

The functions of membranes within cells are to:

1. Control the entry and exit of materials in discrete organelles, such as what?

A

The functions of membranes within cells are to control the entry and exit of materials in discrete organelles, such as:

  1. Mitochondria
  2. Chloroplasts
63
Q

The functions of membranes within cells are to:

  1. Control the entry and exit of materials in discrete organelles, such as mitochondria and chloroplasts.
  2. Separate what?
A

The functions of membranes within cells are to separate organelles from the cytoplasm

64
Q

The functions of membranes within cells are to:

  1. Control the entry and exit of materials in discrete organelles, such as mitochondria and chloroplasts.
  2. Separate organelles from the cytoplasm, so that what?
A

The functions of membranes within cells are to separate organelles from the cytoplasm, so that specific metabolic reactions can take place within them

65
Q

The functions of membranes within cells are to:

  1. Control the entry and exit of materials in discrete organelles, such as mitochondria and chloroplasts.
  2. Separate organelles from the cytoplasm, so that specific metabolic reactions can take place within them.
  3. Provide a what system?
A

The functions of membranes within cells are to provide an internal transport system

66
Q

The functions of membranes within cells are to:

  1. Control the entry and exit of materials in discrete organelles, such as mitochondria and chloroplasts.
  2. Separate organelles from the cytoplasm, so that specific metabolic reactions can take place within them.
  3. Provide an internal transport system, for example what?
A

The functions of membranes within cells are to provide an internal transport system, for example endoplasmic reticulum

67
Q

The functions of membranes within cells are to:

  1. Control the entry and exit of materials in discrete organelles, such as mitochondria and chloroplasts.
  2. Separate organelles from the cytoplasm, so that specific metabolic reactions can take place within them.
  3. Provide an internal transport system, for example endoplasmic reticulum.
  4. Isolate what?
A

The functions of membranes within cells are to isolate enzymes that might damage the cell

68
Q

The functions of membranes within cells are to:

  1. Control the entry and exit of materials in discrete organelles, such as mitochondria and chloroplasts.
  2. Separate organelles from the cytoplasm, so that specific metabolic reactions can take place within them.
  3. Provide an internal transport system, for example endoplasmic reticulum.
  4. Isolate enzymes that might damage the cell, for example what?
A

The functions of membranes within cells are to isolate enzymes that might damage the cell, for example lysosomes

69
Q

The functions of membranes within cells are to:

  1. Control the entry and exit of materials in discrete organelles, such as mitochondria and chloroplasts.
  2. Separate organelles from the cytoplasm, so that specific metabolic reactions can take place within them.
  3. Provide an internal transport system, for example endoplasmic reticulum.
  4. Isolate enzymes that might damage the cell, for example lysosomes.
  5. Provide what on which reactions can occur?
A

The functions of membranes within cells are to provide surfaces on which reactions can occur

70
Q

The functions of membranes within cells are to:
1. Control the entry and exit of materials in discrete organelles, such as mitochondria and chloroplasts.
2. Separate organelles from the cytoplasm, so that specific metabolic reactions can take place within them.
3. Provide an internal transport system, for example endoplasmic reticulum.
4. Isolate enzymes that might damage the cell, for example lysosomes.
5. Provide surfaces on which reactions can occur.
Example

A

For example, protein synthesis using ribosomes on rough endoplasmic reticulum

71
Q

Permeability of the cell-surface membrane:
The cell-surface membrane controls the movement of substances into and out of the cell.
In general, most molecules do not freely do what?

A

In general, most molecules do not freely diffuse across the cell-surface membrane

72
Q

Permeability of the cell-surface membrane:
The cell-surface membrane controls the movement of substances into and out of the cell.
In general, most molecules do not freely diffuse across the cell-surface membrane, because many are:
1. Not soluble in what?

A

In general, most molecules do not freely diffuse across the cell-surface membrane, because many are not soluble in lipids

73
Q

Permeability of the cell-surface membrane:
The cell-surface membrane controls the movement of substances into and out of the cell.
In general, most molecules do not freely diffuse across the cell-surface membrane, because many are:
1. Not soluble in lipids and therefore cannot do what?

A

In general, most molecules do not freely diffuse across the cell-surface membrane, because many:

  1. Are not soluble in lipids
  2. Therefore cannot pass through the phospholipid bilayer
74
Q

Permeability of the cell-surface membrane:
The cell-surface membrane controls the movement of substances into and out of the cell.
In general, most molecules do not freely diffuse across the cell-surface membrane, because many are:
1. Not soluble in lipids and therefore cannot pass through the phospholipid bilayer.
2. Too large to pass through what?

A

In general, most molecules do not freely diffuse across the cell-surface membrane, because many are too large to pass through the channels in the membrane

75
Q

Permeability of the cell-surface membrane:
The cell-surface membrane controls the movement of substances into and out of the cell.
In general, most molecules do not freely diffuse across the cell-surface membrane, because many are:
1. Not soluble in lipids and therefore cannot pass through the phospholipid bilayer.
2. Too large to pass through the channels in the membrane.
3. Of the same what as what?

A

In general, most molecules do not freely diffuse across the cell-surface membrane, because many are of the same charge as the charge on the protein channels

76
Q

Permeability of the cell-surface membrane:
The cell-surface membrane controls the movement of substances into and out of the cell.
In general, most molecules do not freely diffuse across the cell-surface membrane, because many are:
1. Not soluble in lipids and therefore cannot pass through the phospholipid bilayer.
2. Too large to pass through the channels in the membrane.
3. Of the same charge as the charge on the protein channels and so even if they are small enough to pass through, they are what?

A

In general, most molecules do not freely diffuse across the cell-surface membrane, because many are:

  1. Of the same charge as the charge on the protein channels
  2. So even if they are small enough to pass through, they are repelled
77
Q

Permeability of the cell-surface membrane:
The cell-surface membrane controls the movement of substances into and out of the cell.
In general, most molecules do not freely diffuse across the cell-surface membrane, because many are:
1. Not soluble in lipids and therefore cannot pass through the phospholipid bilayer.
2. Too large to pass through the channels in the membrane.
3. Of the same charge as the charge on the protein channels and so even if they are small enough to pass through, they are repelled.
4. Electrically what (in other words what)?

A

In general, most molecules do not freely diffuse across the cell-surface membrane, because many are electrically charged (in other words polar)

78
Q

Permeability of the cell-surface membrane:
The cell-surface membrane controls the movement of substances into and out of the cell.
In general, most molecules do not freely diffuse across the cell-surface membrane, because many are:
1. Not soluble in lipids and therefore cannot pass through the phospholipid bilayer.
2. Too large to pass through the channels in the membrane.
3. Of the same charge as the charge on the protein channels and so even if they are small enough to pass through, they are repelled.
4. Electrically charged (in other words polar) and therefore have difficulty passing through what?

A

In general, most molecules do not freely diffuse across the cell-surface membrane, because many are electrically charged (in other words polar) and therefore have difficulty passing through the non-polar hydrophobic tails in the phospholipid bilayer

79
Q

The fluid-mosaic model of the cell-surface membrane:

What is known as the fluid-mosaic model?

A

The way in which all the various molecules are combined into the structure of the cell-surface membrane is known as the fluid-mosaic model

80
Q

The fluid-mosaic model of the cell-surface membrane.

It is fluid, because what?

A

It is fluid, because the individual phospholipid molecules can move relative to one another

81
Q

The fluid-mosaic model of the cell-surface membrane.
It is fluid, because the individual phospholipid molecules can move relative to one another.
This gives the membrane a what structure?

A

This gives the membrane a flexible structure

82
Q

The fluid-mosaic model of the cell-surface membrane.
It is fluid, because the individual phospholipid molecules can move relative to one another.
This gives the membrane a flexible structure that is constantly what?

A

This gives the membrane a flexible structure that is constantly changing in shape

83
Q

The fluid-mosaic model of the cell-surface membrane.
It is fluid, because the individual phospholipid molecules can move relative to one another.
This gives the membrane a flexible structure that is constantly changing in shape.
It is mosaic, because what?

A

It is mosaic, because the proteins that are embedded in the phospholipid bilayer vary in:
1. Shape
2. Size
3. Pattern
in the same way as the stones or tiles of a mosaic

84
Q

Organelles such as what are surrounded by how many plasma membranes?

A

Organelles such as:
1. Mitochondria
2. Chloroplasts
are surrounded by 2 plasma membranes

85
Q

Organelles such as mitochondria and chloroplasts are surrounded by 2 plasma membranes.
The term cell-surface membrane is reserved only for what?

A

The term cell-surface membrane is reserved only for the plasma membrane around the cell

86
Q

When representing a phospholipid, it is important to be accurate.
It has what?

A

A phospholipid has:

  1. A single phosphate head
  2. 2 fatty acid tails
87
Q

All plasma membranes found around and inside cells have the same what structure?

A

All plasma membranes found:
1. Around
2. Inside
cells have the same phospholipid bilayer structure

88
Q

All plasma membranes found around and inside cells have the same phospholipid bilayer structure.
What gives plasma membranes their different properties are what?

A

What gives plasma membranes their different properties are the different substances they contain

89
Q

All plasma membranes found around and inside cells have the same phospholipid bilayer structure.
What gives plasma membranes their different properties are the different substances they contain, especially what?

A

What gives plasma membranes their different properties are the different substances they contain, especially proteins

90
Q

The fluid mosaic model of the plasma membrane:
The proteins can move freely through the phospholipid bilayer.
The ease with which they do this is dependent on what?

A

The ease with which they do this is dependent on the number of phospholipids with unsaturated fatty acids