chapter 3 - cell structure

Question 1

What is an eyepiece graticule

Answer 1

The eyepiece graticule is a glass disk within the eyepiece that has a scale on it.

Question 2

What is a stage micrometer

Answer 2

A stage micrometer is used to calibrate the eyepiece graticule. It is a glass slide with a scale you place on the stage. The scale is roughly 2 mm and each subdivision is 10 µm long.

Question 3

How do you calibrate the eyepiece graticule

Answer 3

1: you place the stage micrometer on the stage
2: lineup the stage micrometer to the eyepiece graticule
3: Count how many divisions from the eyepiece graticule fit into the stage micrometer. eg 2 fit into 1. if 1 division of the stage micrometer is 10 Micrometers
4: find out how big one division is on the eyepiece graticule in this case it would be 5 µm
5: now you can measure the size of organelles by removing the stage micrometer

Question 4

How do enzymes lower activation energy (induced fit model)

Answer 4

When the enzymes active site becomes induced/slightly change the shape to fit around the substrate.
When the enzyme substrate complex forms, Due to the enzyme moulding around the substrate this puts a strain on the bonds between the substrate and the enzyme this creates tension. Therefore less energy is needed to bring the bonds forming the products.

Question 5

What happens when the enzymes denature when the temperature is too high

Answer 5

If the temperature is too high/pass optimum for enzymes denature.

This means that enzymes active site has changed the shape/the tertiary structure has changed shape. This could mean that bonds in a tertiary structure have broken. No more enzyme substrate complex can conform

Question 6

What happens when pH is too high or too low in a reaction

Answer 6

if the pH is too high or too low this will interfere with the charges of amino acids in the active site/enzyme. Disc and brake/change the bonds in the tertiary structure that holds the active site and enzyme in place