Cell stucture Flashcards
What is the protoplasm?
It’s all the living parts of a cell
What is the largest cell and smallest smell in humans?
Largest - egg
Smallest - sperm
Why must cells be stained?
Organelles are colourless
What stain is used to see onion cells?
Iodine
What stain is used for cheek cells?
Methylene blue
What does the electron microscope do?
It shows the ultra structure of cells
What is the composition and function of the cell membrane?
Composition - phospho lipid bilayer and protein
Function - selectively permeable
What is the composition and function of the cytoplasm?
C - jelly-like fluid, mostly water
F - Chemical reactions
What is the composition and function of the nucleus?
C - nuclear membrane containing chromatin
F - controls all cells activities
What is chromatin made of
Protein and DNA
What is the function of nuclear pores?
Allow chemicals in and out of the nucleus
What is the function of the nucleolus
It makes ribosomes
What is the composition and function of the cell wall?
C - cellulose
F - provides strength + makes less flexible
What is the composition of the vacuole and it’s function?
C - cell sap [membrane]
F - stores water and salts also give strength and shape
Composition and function of chloroplasts
C - double membrane containing chlorophyll and DNA
F - photosynthesis
Composition and function of mitochondria
C - double membrane containing DNA
F - Respiration
Why are mitochondria plentiful in active cells?
A lot of energy is required and mitochondria release energy in respiration
Composition and function of ribosomes
C - RNA
F - protein synthesis
What is a cell sap made up of?
Sugar salts and water
Prepare slide for animal cell for examination
1) few drops of water on slide
2) using finger, rub mouth place on slide
3) dropper, add drops of methylene blue
4) mounted needle, lower coverslip
What was the purpose of the glass slide?
Allow light to pass through it
What was the purpose of the coverslip?
Holds the cells in place and stops it from drying out
How did you examine the cells under the microscope?
Lenses = magnify Wheels = focus Diaphragm = light
What was it difficult to see cells under low power
Cells are spread out and smaller
What are the three types of microscopes?
A simple light microscope
A compound light microscope
An electron microscope
What is a simple light microscope?
Uses one lens to magnify object
What is a compound light microscope?
Uses two or more lenses to magnify an object
What is an electron microscope?
It uses beams of electrons instead of light
What are the two types of electron microscopes?
Transmitting and Scanning electron microscopes
What is the transmitting electron microscope?
Electrons pass through specimen to show inside parts
What is the scanning electron microscope
Electrons reflected off surface to show outside parts
What is the function of the eyepiece?
Magnifies image
What is the function of the coarse adjustment wheel?
Rough focusing
Function of fine adjustment wheel?
Precise/sharper focusing
Function of rotating nosepiece?
Revolves to move desired lens into position
Function of the objective lens?
Magnifies image
Function of clips
Holds slide in place
Function of stage?
Area on which slide is placed
Function of iris diaphragm
Controls amount of light reaching object
Function of condenser?
Focuses light onto slide
Function of light source
Supplies light to object
State one advantage of an electron microscope
Able to see the ultra structure of the cell
What part of the stage will you place the slide?
Above the hole where the light is
Why is it important to watch from the side, not the top, while raising the stage to met the lens?
To make sure the objective lens does not end up being damaged by hitting off the stage
Molecules can move through cell membranes by various processes, name two
Osmosis, diffusion, Active transport
Name an organelle other than the nucleus which contains genetic material
Mitochondria or chloroplasts
Give two features of eukaryotic cells which distinguish them from prokaryotic
Membrane bound organelles
Nucleus
State the precise location of the cell membrane in plant cells
Inside cell wall
Name the two molecules present in a cell membrane
Protein and phospholipid
How did you transfer cells to a slide of a
- plant cell
- animal cell
- plant cell = forceps
- animal cell = swab
How did you improve the visibly of the cells on the slide in the experiments
Add a stain
State the precise location of the cell membrane in plant cells
Inside cell wall
State the precise location of the cell membrane in animal cells
It’s the outermost later
With what type of cell do you associate membrane-bound organelles?
Eukaryotic
How did you obtain the animal cell?
Swan inside of cheek surface with sterile loop
Describe the difference in colour or depth of colour between the nucleus and cytoplasm when stained cell was viewed under the microscope
Cytoplasm - paler
Nucleus - darker
How did you apply the cover slip?
The cover slip is lowered onto the slide, using a mounted needle at a 45 degree angle
Diagram of mitochondria and chloroplast
pg 108 of exam papers
C - weird strings
Give locations in a cell which there is a selectively permeable membrane
Nucleus, chloroplast, vacuole, mitochondria
Give two features of eukaryotic cells which distinguish them from prokaryotic cells
- Nucleus
- membrane bound organelles
Lens X is 10X and lens Y is 40X. The image of the cell is 1.2mm in diameter
How do you find actual diameter of a cell?
Multiply lenses - 400
Divide by magnification
Labelled diagram of plant cells as seen high power
Not ultrasturcture! Normal plant diagram
