Test 1 Flashcards
Major differences between eukaryotes and prokaryotes?
The nucleus is the main difference.
Eukaryotes have a nucleus and membrane-bound organelles, whereas prokaryotes do not.
What is the central dogma of biology?
The process of turning genetic information into proteins.
All information needed for life is stored in the nucleus as DNA.
We must translate DNA to RNA then transcribe the RNA into proteins.
Describe the role of the nuclear envelope.
The envelope separates the nucleoplasm and the cytoplasm.
In eukaryotes the N.E. Separates transcription and translation to fulfill precise regulation.
Describe the role of the Endoplasmic reticulum and Golgi apparatus.
The ER makes the different phospholipid components of the membrane and ships them to the Golgi apparatus. The ER forms the outer membrane of the nuclear envelope. The ER pumps and channels to regulate the cytoplasmic Calcium concentration.
The Golgi apparatus then adds different membrane proteins, and lysosomal proteins to the phospholipids.
Describe the role of lysosomes and peroxisomes.
Lysosomes contain digestive enzymes and segregate these enzymes from the rest of the cell to avoid destroying internal structures.
Peroxisomes contain enzymes involved in the breakdown of hydrogen peroxide.
Describe the role of the mitochondria.
The mitochondria synthesizes ATP that drives enzymes into the membrane that are necessary for eukaryotic cells.
These characteristics allow for cells to achieve regulation and avoid side effects of toxicity.
Describe the plasma membrane.
Proteins located in the plasma membrane are needed for transport and adhesion.
The interior of the plasma membrane is hydrophobic, and the outside is hydrophilic. The plasma lipid consists of a phospholipids and is semipermeable.
The membrane is impermeable to ions and most water-soluble molecules. They can only travel through different channels, pumps, and carriers. The plasma membrane is also home to many different transmembrane receptors and extracellulcar matrixes.
Describe the cytoskeleton and the cell’s motility apparatus.
The cytoskeleton maintains the shape of most cells.
The cytoskeleton has three different protein polymers.
1) Actin filaments: facilitate cellular movements in collaboration with microtubules
2) Intermediate filaments: form bundles that link plasma membrane to nucleus
3) Microtubules: facilitate cellular movements in sync with actin filaments
Describe the nucleus and NPC.
The nucleus is surrounded by the nuclear envelope which is a double membrane and transports via the nuclear pore complex (NPC).
Outbound transport of the nucleus includes RNA and ribosomal subunits. Inbound transport includes nuclear proteins.
What is the reductionist strategy and why is it used?
Human body -> systems -> organs -> tissues -> cells -> molecules
1) To identify the molecular parts of cellular machine
2) To figure out the working mechanisms
3) To achieve target intervention
Different features of fluorescence microscopy?
Confocal Microscopy
- most commonly used microscope in cell biology
Superresolution Fluorescence
- Absorption of a photon raises an election to excited state. A longer wavelength photon is emitted when electron falls to ground state.
- Different sources of fluorescence can bind to proteins, lipids, nucleic acids, and different ligands.
What are the two main functions of microscopes?
1) To enlarge an image
2) To produce contrast
What is immunofluorescence?
Fluorescent antibody staining.
Important because this allows antibodies to diffuse through the cell membrane in order to find its target molecule.
1) Primary antibody is made target.
2) Secondary antibody is conjugated w/ dye to find primary antibody. By tagging the primary antibody it indirectly tags the target molecule
What is electron microscopy?
Electron microscopy is used to observe fine details of cell structures. You can see the E.R., Golgi apparatus, nuclear envelope and more. Uses electrons to produce image instead of light, and you cannot use a live sample.
Preparation for Transmission Electron Microscopy.
1) Must cut sample into thin sections that are fixed and dehydrated.
2) Then frozen-hydrated by freezing rapidly.
3) Next you must negatively stain sample.
