Cell & Molecular Biology Flashcards
What is an eukaryotic cell?
Plant or animal cell
What is a prokaryotic cell?
Bacteria (single organism)
What is magnification?
Enlargement of an image
What is resolution?
Measure of clarity of an image
What is contrast?
Difference in brightness between light and dark areas of an image
What are the different types of microscope?
Light microscope (LM): Fluorence microscope
Electron microscope (EM): Scanning electron microscope (SEM) + Transmission electron microscope (TEM)
What is light microscopy used for?
Used to visualise whole cells and large subcellular organelles (nucleus, chromosomes)
Fluorescence to stain
What is electron microscopy used for?
EMs use electronmagnets to focus a beam of electrons through/inside the specimen (TEM) or onto its surface (SEM)
What is TEM used for?
To study internal cell structure: organelles, proteins and nucleic acids
Focus a beam of electrons through the specimen
What is SEM used for?
To study cell surface and generate 3D images
Focus a beam of electrons onto the surface of specimen
Remember this
Order of organelles in cell fractionation
Nuclei -> Mitochondria -> Ribosomes
What does prokaryotic cells have instead of a nucleus?
A nucleoid (DNA concentrated but not enclosed by membrane)
Does prokaryotic cells have organelles?
No. Little or no internal structure or organelles
Does prokaryotic cells have ribosomes?
Yes to synthesise proteins
What organelles do prokaryotic cells have?
- Plasma membrane (encloses cytoplasm)
- Fimbriae (attachment to other bacteria)
- Flagella (locomotion)
- Cell wall (rigid structure)
- Glycocalyx (outer coating consisting of a capsule or slime layer)
- Ribosomes
- Nucleoid
Do eukaryotic cells have a nucleus?
Yes, a membrane bound nucleus which contains most of the cell’s DNA
Do animal cells have a cell wall?
No