Chapter 4 Flashcards
Differentiate between light and electron microscopy and give examples of the types of cells or cell structures that would be best visualized by each of these types of microscopes.
Light microscopy - uses light photons to illuminate objects, color image
Electron microscopy - uses light electrons to illuminate objects, black and white image
What properties do ALL cells share?
- Highly complex and organized
- Repair themselves
- Reproduce
- Grow and develop
- Carry out a variety of chemical reactions
- Perform mechanical work
- Sense and respond to stimuli
- Acquire and utilize energy from environment
What are the advantages to compartmentalizing the inside of a cell with microcompartments or organelles?
Compartmentalizing offers separation of incompatible chemical reactions and increased efficiency of chemical reactions
Describe the main features of a typical prokaryotic cell and include: location of genetic material, location of protein synthesis, types of cell membranes/cells walls, mechanisms of locomotion, types of organelles that have been identified in prokaryotes, and types of cytoskeletal proteins.
Prokaryotic- smaller than eukaryotic cells, have no nucleus, lacks organelle, all prokaryotic are encased by cell walls,, mostly singled felled (unicell), no nucleus, cell wall serves as protection, maintains shape, it also has flagella, cell size 0.1-5.0um.
What are some of the major differences between prokaryotic and eukaryotic cells
Eukaryotic cells have a nucleus containing genetic material while prokaryotic cells have free-floating genetic material b/c they lack a nucleus
What are the major differences between plant and animal cells?
Plant cells have a cell wall, chloroplasts plastids (food storing organelles) and a large central vacuole – animal cells do not
Animal cells have centrioles (a small structure of microtubules located in centrosome)
What is the endomembrane system?
Rough ER (site of protein synthesis) and Smooth ER (creation of lipids and steroids), Golgi Apparatus (proteins from ER are processed further and packaged for transport for lysosomes or the plasma membrane), Vesicles (contain enzymes that break down waste/toxic materials), and Lysosomes (digestive system)
Refer to figure 4.18 of the textbook to answer this question: Describe the cellular locations that a secretory protein travels through from its point of synthesis to its release from the cell.
Rough ER to Golgi to cell exterior
What prevents proteins from becoming lost on their way to the plasma membrane?
Proteins are packaged into vesicles as they leave the Rough ER; the vesicles are then transported to the Golgi and then to the surface of the cell or to other organelles
Describe the functions of endocytosis (phagocytosis, pinocytosis, endocytosis - selective uptake of particles) and exocytosis, and give examples of each of these.
- Phagocytosis- cell eating
- Pinocytosis- cell drinking and receptor- mediated
- Endocytosis- selective uptake of particles
- Exocytosis : Proteins are sent and release their contents to the cell surface in vesicles that fuse with plasma membrane
What are the functions of the cytoskeleton and what are its major components?
It changes to alter cell’s shape, transport materials in the cell, or to move the cell
The cytoskeleton is made up of three fibers: Microtubules (movement within the cell), Actin filaments or “microfilaments” (cell shape and whole cell movement), and Intermediate filaments (cell structure and support)
How are the structures of each of the filament types related to their functions? Give an example for each: microfilaments, intermediate filaments and microtubules.
Microtubules are large and hollow tubes that can grow/shrink through the addition of removal of tubulin units
How do lysosomes function in maintaining general cell health, and facilitating the breakdown of ingested particles or invading microorganisms?
Lysosomes are used for digestion and waste processing and recycling cell components; they contain 40 different digestive enzymes
What is the function of the extracellular matrix in animals?
Holds cells together, and allows tissues to communicate with each other.
Describe the major functions of each of the three types of intercellular junctions in animal cells, and include whether these junctions allow the passage of substances from one cell to another.
Gap Junctions- moves cell to cell and opens and closes. Allows water, ions and other proteins etc to pass through.
Desmosomes- prevents linkage and allows passage of one substance to another
Tight Junction- digestive and making sure nothing leaks, allows passage of one substance to another
