Cytology Flashcards
Brightfield unstained
Little contrast in pigmented cells
Brightfield stained
Must preserve, stain offers contrast
Phase contrast
Unstained = LIVING CELLS, amplifies density
Differential interference “Namarski”
Differences in density, 3D image
Fluorescence
Antibodies can tag different molecules of the cell
Confocal
Use lasers to section fluorescently stained specimen
Difference between prokaryotes and eukaryotes
Prokaryotes have no membrane bound nucleus, lack organelles, no lysosomes, usually smaller
Parts of a prokaryote
Pills, nucleoid, ribosomes, plasma membrane, cell wall, capsule, flagella
Double membrane bound organelles
Nucleus and mitochondria
No membrane organelles
Nucleolus, ribosomes, cytoskeleton
Features of the plasma membrane
Amphipathic, selective barrier, fluid mosaic
Where are tight junctions found?
The apical end of the membrane, and typically in the gut
What are desmosomes?
Loose junctions around the cell, typically in between cells, usually found on epithelial cells
Gap junctions
Holes connecting neighboring cells to share nutrients
How does light microscopy work?
Light come out from the source at the bottom then goes through the condenser lens, specimen, objective lens, bounces off a mirror, through the projector lens then to eye
What is the difference between heterochromatin and euchromatin?
Hetero - dense, coiled, not active
Eu - diffuse, open, spread out
If a protein needs to be secreted out of a cell after translation, what must happen?
The ribosome must bring the protein to the ER before its done translating
T/F. The ER is continuous with the nucleus
True. It’s in direct contact with the nuclear pore
What does the ER do?
Detoxification, ion storage, makes new membranes
What are some endosomal compartments?
Endosomes, lysosomes, peroxisomes, recycling compartments
What does the cytoskeleton do?
Determines cell shape, locomotion, intravenous are trafficking
Microfilaments
Smallest, made of tight and loose junctions
ex: actin and myosin - parallel, planar, polar, anchorage
Microtubules
Largest, hollow
Involved in cilia, flagella, militia spindle
Ex - dynein and kinesin are motor proteins
What is the arrangement of microtubules in cilia and flagella?
9 fused pairs on the outside of a cylinder with 2 infused in the middle
What is the point of intermediate filaments?
To maintain architectural support and stability
Role of DNA in protein synthesis
- The nucleus contains chromosomes
- Chromosomes contain DNA
- DNA stores genetic info for proteins
- Proteins determine cell structure and function
Helicase
Breaks daughter strands and unwinds
Dna primase
Sets the RNA primer to get ready for base pairing
DNA polymerase
Recognizes primer and goes to town to add nucleotides
DNa ligase
Fills in Okazaki fragments
Can polar molecules pass through membrane easily?
No. Need membrane transport proteins
Simple diffusion
No energy needed
Small NP molecules can move easily across membrane based on size, temp, and concentration gradient
Carrier mediated transport
Can be limited by carrier specificity, become saturated, or be regulated by hormones or other signals
Active transport
Energy needed, against gradient
Two types of endocytosis
Phagocytosis - food
Pinocytosis - drink
What is a clathrin coated pit?
A vesicle coated with clathrin, can beat formed in receptor mediated endocytosis
What happens in G1 phase?
Allows cells to grow in size and make proteins
M phase
Mitosis
What happens in G0 phase?
Cells are done dividing, like muscle cells and neurons, will last a while then die
G2 phase?
Cells prepare for division
S phase?
Synthesis, DNA replication
Parts of mitosis
Interphase, prophase, metaphase, anaphase, telophase
Two identical 2n daughter cells
Meiosis
Make 4 haploid genetically different daughter cells
What is nondisjunction and when does it occur?
When chromosomes do not divide evenly. Can happen in anaphase 1 or 2
What is crossover?
The exchange of genetic material of HOMOLOGUS chromosomes during meiosis
Necrosis
Cell death by disease
Apoptosis
Programmed cell death, desirable, determined, must make room for other cells