Cell Stucture And Function Flashcards
Define prokaryote cell
Cell that has no membrane bound organelles
No nucleus
Define eukaryotes cell
Cell that has a nucleus
What organelles are in a plant cell but not in an animal cell?
Tonoplast
Vacuole
Amyloplasts
Chloroplast
What are the different types of bacteria cells?
Gram positive
Gram negative
Characteristics of gram positive bacterial cell
1 cell surface membrane
no outer membrane
Thick cell wall (peptidoglycan)
Characteristics of gram negative bacterial cell
2 cell surface membranes
(outer membrane)
Thin cell wall (peptidoglycan)
Describe the gram stain method
Crystal violet (stains all purple)
Ethanol (decolourises gram -ve)
Safarin (stains gram -ve pink)
Gram +ve = purple
Gram -ve = pink
What do electron microscopes generate?
Beams of electrons
What is used to focus on a specimen?
Electromagnets
What is a electron micrograph?
The image produced that is projected onto a screen
Black and white image
Why do electron microscopes have higher resolutions than light microscopes?
Electron beams have shorter wavelength than light
What can samples be stained with?
Radioactive salts
What does staining do? (Electron microscopes)
Distinguish different features
Gives micrograph contrast
How are false coloured electron micrograph coloured?
Digitally on computers
What is an electron microscope magnification?
500,000
