Module 1: Lesson 2 Flashcards
What are the types of prokaryotes?
archaea and bacteria
nucleus
holds genetic information
nuclear envelope
separates transcription from translation
Endoplasmic reticulum (ER)
secreted and membrane protein synthesis, Ca2+ storage/signaling, linked by vesicle transport to all other endomembranes
Golgi apparatus
glycosylation and sorting of proteins for transport/secretion
Lysosome
digestion (hydrolysis); peroxisome - oxidative metabolic functions
Vesicles
transport between endomembrane organelles
flagellum
for motility and sensing (eg. cilia)
Plasma membrane (PM)
separates the cell from the environment
Mitochondria
oxidative phosphorylation for ATP synthesis
Chloroplast
photosynthesis for ATP synthesis
Cytoskeleton
cell shape, cell motility, intracellular transport of organelles
What is the problem and what are the solutions to transmitted light microscopy?
Problem: cells are mostly transparent
Solutions: stain cells with dyes to generate contrast, and optics that generate contrast where there is a difference in density/refractive index in cells
What is the nuclear envelope contiguous with?
the endoplasmic reticulum
Nuclear pore complex
regulates the movement of macromolecules (RNA and proteins) in and out of the nucleus
Why can electrons be used for microscopy?
electrons have shorter wavelengths and high magnification and resolution
Fluorescence microscopy
allows the detection of specific proteins or other molecules that are labeled with fluorescent molecules
Steps of fluorescence microscopy
- an electron is excited by a high-energy proton
- relaxation causes the emission of a photon of lower energy than the one that caused the excitation
How do you fluoresce live cells and tissues?
use live dyes to illuminate the specimen, and use genetically encoded fluorophores to identify the target: reporters or protein fusions
How do you fluoresce fixed cells and tissues?
use dyes to illuminate the specimen, and use antibodies to identify the target: direct and indirect labeling
What are traits of the ER?
it is continuous with the nuclear membrane, contains the most membrane of the cell, has tubular membranes or flattened sacs, and the inside of the ER is lumen.
What are the traits and role of the rough ER?
rough ER is decorated in ribosomes on the outer surface, thus appearing “rough.” It synthesizes proteins that are exported out of the cell (secretion and exocytosis) and some membrane proteins.
What are the roles of the smooth ER?
smooth ER has no role in protein synthesis and no associated ribosomes. It synthesizes lipids, sterols, and steroid hormones; detoxifies drugs and toxins; and stores calcium ions and specialized sub-domains.
What is the role and characteristics of the Golgi complex?
the Golgi complex chemically modifies, sorts, and packages proteins from the rER. It consists of 3-8 flattened membrane-bound cisternae in a stack.
What are the roles and characteristics of vesicles?
vesicles transport proteins and membranes to endomembrane organelles and the plasma membrane. They are small membrane-bound spherical “bubbles” that only carry proteins appropriate to their destination.
What are lysosomes and what is their role?
lysosomes are small, single membrane organelles with low pH that degrade and recycle components of the cell’s organelles. This includes carbohydrates, lipids, proteins, and older organelles.
What do peroxisomes do?
peroxisomes are organelles that can handle hydrogen peroxide and other reactive oxygen species using special enzymes. They conduct fatty acid oxidation.
What are lipid droplets?
a single phospholipid monolayer that surrounds a core of neutral lipids: sterol esters and triglycerides. They are decorated with proteins and can interact with different organelles.
What is the cytoskeleton?
a system of protein filaments in the cell that undergo dynamic reorganizations. It contributes to cell motility, intracellular motility and organization, cell shape, rigidity, and structural support.
What are the types of filaments?
Actin filaments, microtubules, and intermediate filaments.
What is the difference between flagellum and cilium?
a flagellum is designed to move the entire cell, whereas a cilia has an equivalent structure but is shorter and more abundant.
What is the role and characteristics of the mitochondria?
the mitochondria are involved with energy production and cell signaling. It is a double-membrane bound organelle made of cristae; has its own genome; and possesses the ability to move, fuse, and divide individually.
What are chloroplasts and what is their role?
chloroplasts conduct ATP synthesis via photosynthesis in photosynthetic eukaryotes. This occurs in the thylakoid. Chloroplasts also have the individual ability to move, fuse, and divide; and it has its own genome.
