The cell Flashcards
Eukaryotic cells vs. prokaryotic
Eukaryotic:
-Has true nucleus
-Has membrane bound organelles
-Can be unicellular or multicellular
Prokaryotic:
-No real nucleus
-No membrane bound organelles
-Unicellular
Nucleus
Contains chromosomal/genetic information
-Has double membrane called envelope, including pores that allow proteins in and out
Where is the nucleolus found and what does it do?
Found within the nucleus
Site of rRNA formation
What is the purpose and make-up of the mitochondria?
Produces ATP, also the site of electron transport chain and citric acid cycle, and can cause apoptosis
Has a double membrane that consists of an inner membrane (mitochondrial matrix), outer membrane, and intermembrane space
What is special about the mitochondria’s DNA?
-It is circular and can replicate through binary fission, separate from nuclear DNA replication
-Double stranded
-Extranuclear inheritance- means it can transmit genetic info without the nucleus (all mitochondria inherited from maternal side)
What purpose do lysosomes serve?
Hydrolyze cellular waste by engulfing foreign bodies
-Done through endocytosis or with waste already inside cell
-Can also cause apoptosis if they lyse and spread acidic material into cell
What are the two sections of Endoplasmic Reticulum and what do they do?
Rough ER:
-Has ribosomes
-Site of protein synthesis
Smooth ER:
-Lacks ribosomes
-Lipid synthesis, detox, and transports proteins to Golgi body
What role does the golgi body play?
“Mail room” of the cell
Receives proteins from ER, packages/modifies them, and sends them to correct location
-Also performs exocytosis (sending something outside the cell)
What role do peroxisomes play?
Neutralize oxidizers in the cell
-breakdown of fatty acids through beta-oxidation
What are the 3 components of the cytoskeleton?
Microfilaments, intermediate filaments, and microtubules
What are microtubules made up of, and what structures can they create?
Tubulin
-Make paths for “walking proteins”
-Make up cilia and flagella
-Make up centrioles/mitotic spindles
What are microfilaments made up of, and what structures can they create?
Actin
-Provides cellular protection
-Forms cleavage furrow
-Used in muscle contractions
What are intermediate filaments made up of, and what structures can they create?
Made up of diverse # of proteins
-Cell-to-cell adhesions
-Cytoskeleton integrity
-Anchors organelles
What is epithelial tissue and what role does it play?
The tissue that covers the body and lines cavities/the functional part of organs
Protects against pathogens
What are the three types of epithelial tissues?
Simple –> one layer of cells
Stratified –> multiple layers of cells
Pseudo-stratified –> Appears as though there’s multiple layers, but there’s really only one
What are the three shapes of epithelial tissues?
Cuboidal –> cubes
Columnar –> long and thin
Squamos –> flat and scale-like
Connective tissue makes up the ____ and secretes materials to form the _____
Stroma
Forms the extracellular matrix
Attaches to epithelial tissue to support the body and create framework for epithelial cells
What are the three shapes of bacteria?
Cocci –> spherical
Bacilli –> rod
Spirilli –> spiral
What is the difference between obligate and facultative aerobes/anaerobes?
Obligate means the cell absolutely can or cannot have air
Facultative means the cell can switch between needing air or not needing air depending on the situation
In prokaryotes, what is recombination?
Plasmids on the outside of the cell carry genetic information that can be transferred to other cells
In prokaryotes, what is transformation?
The integration of foreign material into the host genome
In prokaryotes, what is conjugation?
Sexual reproduction, where F+ cell will use its sex pillus to form a conjugation bridge and pass the material from the F+ male to F- female
-This can only occur between a F+ and F- cell, after which both cells will be F+
In prokaryotes, what is transduction?
Requires a vector (virus that carries genes from one bacteria to another)
-usually occurs from accidental transfer from bacteriophages
What are the bacteria growth phases?
Lag –> bacteria adapts to new environment
Log (exponential)–> bacteria begins to rapidly replicate
Stationary –> reducation of resources slows down replication
Death –> resources are depleted so cells cannot survive
What kind of DNA do viruses have?
Any kind: double or single stranded, circular or linear, RNA or DNA
What is the difference between positive and negative sense RNA?
Always single stranded
Positive sense is ready to be translated into proteins (think of it like mRNA)
Negative sense acts as a template for a complimentary strand, which is then used as a protein synthesis template
-Requires RNA replicase
What is the life cycle of viruses?
Infection –> the virus binds to target cells by binding to receptors or fusing with plasma membrane
Translation/progeny assembly –> genetic material goes to the proper location where it is then translated into proteins, which in turn creates new viroids
Progeny release –> Can either be done through cell lysing (disadvantage –> kills cell so it can’t make any more viroids) or through extrusion where viroids pinch off membrane and enter the body
What is the difference between the lytic and lysogenic phase for bacteriophages?
Lytic phase occurs when the bacteriophage harnesses the cell to continuously create new virons (virulent phase)
Lysogenic phase occurs when the bacteriophage’s genetic material is sitting dormant in the cell
-The genetic material fuses with the bacteria and is replicated with that bacteria
-Certain conditions cause return to lytic phase
What are prions?
Implicated in the misfiling of proteins
