required pracs Flashcards
1
Q
apparatus for microscopy
A
- microscope
- glass slide
-coverslip
-iodine
-onion
-paper towel
-
1
Q
how to prepare a slide microscopy
A
- pull off epidermal layer of onion
- put into slide with a drop of iodine to keep flat
- put on a drop of iodine to stain cells/make visable
- use a needle to carefully lower the coverslip onto the slide with no air bubbles
- use filter paper to soak up any excess on slide
2
Q
how to use the microscope, microscopy
A
- place slide on stage
- turn nosepeiece to select low power objective
- use course adjustment knob until cover slip touches objective lense
- then use the eyepiece and turn the knob until the image is in focus
5.turn nosepiece to higher power objective, higher mag - Go back to eyepiece and turn course objective knob and fine adjustment knob
- repeat this
3
Q
measuring in microscopy
A
- make note of the magnification
- use microscope to find number of cells along one line
- put ruler under and measure how many dents representing mm there are on the line of cells
- use actual x mag = image
4
Q
osmosis equiptment
A
- tissue eg potato- same length and no skin
- cork borer for cutting
- ruler
- balance
- range of solutions and water
- test tubes and rack
- paper towel
5
Q
preparing for osmosis practical
A
- cut potatoes using cork borer into identical cyclinders
- use knife to trim to same length and to remove skin
- measure and record length and mass
- measure 10cm of all of the sugar solutions and water
- add each potato cylinder to each tube
6
Q
second half of osmosis practical
A
- leave tubes overngith on a rack
- remove potato cylinders and blot dry
- measure length and mass and record
7
Q
saftey in osmosis
A
- handle knife carefully
- do not eat or drink solution or potatoes
8
Q
result of osmosis practical
A
- when in distilled water it will gain most weight as it is less concentrated with water than the distilled water so it will move into the potato
- wehn in highly sugar concentrated water the water in the potato will move out to an area of lower water conc and so will lose weight
9
Q
preparation for food tests
A
- grind food sample using motar and pestle
- put in beaker and add water, stir
- filter using filtration and collect in a flask so solution is clear
- half fill a test tube
10
Q
test for sugar
A
- add 10 drops of benedict solution to that in test tube
- will go from blue to green/yellow/red depending on conc of sugar
11
Q
special extra work in test for sugar
A
- heat water to point of boiling
- put in beaker
- put test tube of solution in beaker for five minutes
12
Q
test for starch
A
- put a few drops of iodine into solution
- will go from brick orange to blue black
13
Q
test for protien
A
- add ten drops of buriet to solution
- will go from blue to purple
14
Q
test for lipids
A
- add ten drops of ethanol to solution
- will go cloudy emulsion
