1.1 Explain the appropriateness of light and electron microscopes for different purposes.
Explain the difference between magnification and resolution (2)
Magnification is how much you can enlarge an image
Resolution is how sharp and clear your microscope can show an image
State the resolution that can be achieved by each of the following types of microscope (2)
Light microscope.
200nm
Transmission electron microscope.
0.5nm
Explain the appropriateness of light and electron microscopes for different purposes. (6)
A light microscope can be used for objects as small as 200nm, they can resolve bacteria but cannot resolve viruses. They can reveal structures such as mitochondria, chloroplasts and the nucleus. Light microscopes are commonly …show more content…
Draw and label a simple diagram of a phospholipid molecule (2)
Why are the phospholipid molecules arranged in a bilayer? (2)
So the hydrophilic phosphate groups are both orientated towards the water present on the outside and on the inside of the cell
What is the role of the phospholipid bilayer? (1)
To act as a barrier to the entry of water soluble molecules such as glucose which can only cross membranes through protein channels
Why is the term “fluid-mosaic” used to describe cell membrane structure? (2)
Fluid because single phospholipids and proteins can move around freely within the layer, like it’s a liquid
Mosaic because of the pattern the scattered protein molecules produce when the membrane is viewed from above
Draw a diagram to show the arrangement of molecules in the fluid-mosaic model of membrane structure. Describe the role of each type of molecule that you have
Explain the difference between magnification and resolution (2)
Magnification is how much you can enlarge an image
Resolution is how sharp and clear your microscope can show an image
State the resolution that can be achieved by each of the following types of microscope (2)
Light microscope.
200nm
Transmission electron microscope.
0.5nm
Explain the appropriateness of light and electron microscopes for different purposes. (6)
A light microscope can be used for objects as small as 200nm, they can resolve bacteria but cannot resolve viruses. They can reveal structures such as mitochondria, chloroplasts and the nucleus. Light microscopes are commonly …show more content…
Draw and label a simple diagram of a phospholipid molecule (2)
Why are the phospholipid molecules arranged in a bilayer? (2)
So the hydrophilic phosphate groups are both orientated towards the water present on the outside and on the inside of the cell
What is the role of the phospholipid bilayer? (1)
To act as a barrier to the entry of water soluble molecules such as glucose which can only cross membranes through protein channels
Why is the term “fluid-mosaic” used to describe cell membrane structure? (2)
Fluid because single phospholipids and proteins can move around freely within the layer, like it’s a liquid
Mosaic because of the pattern the scattered protein molecules produce when the membrane is viewed from above
Draw a diagram to show the arrangement of molecules in the fluid-mosaic model of membrane structure. Describe the role of each type of molecule that you have