Cell Theory
All living thins are composed of cells
The cell is the basic functional unit of life
Cells arise only from preexisting cells
Cells carry genetic information in the form of DNA passed from parent to daughter cell
Eukaryote
Have membrane-bound organelles, a nucleus, and may form multicellular organisms
Cytosol
Suspends the organelles, allows diffusion of molecules
Nucleus
Contains DNA organized into chromosomes
Nuclear Membrane
Surrounds nucleus, contains pores for exchange
Nucleolus
Subsection of the nucleus in which ribosomal RNA (rRNA) is synthesized
Mitochondria
Outer membrane - forms barrier with cytosol
Inner membrane - folded into cristae and contains exymes for the electron transport chain (ETC)
Can divide independently via binary fission
Trigger apoptosis by releasing enzymes into the cytosol
Lysozymes
Contain hydrolytic enzymes that break down cellular waste
Autolysis
Release of lysozyme enzymes
Endoplasmic Reticulum
Series of interconnected membranes continuous with nuclear envelope
Rough ER
Studded with ribosomes, conduct translation of proteins destined for secretion
Smooth ER
Lipid synthesis and detoxification
Golgi Apparatus
Stacked sacs in which cellular products are modified, packaged, and directed to specific cellular locations
Peroxisomes
Contain hydrogen peroxide, break down long chain fatty-acids via Beta-oxidation
Cytoskeleton
Provides stability and rigidity to structure of cell as well as transport pathways
Microfilaments
Composed of actin
Muscle contraction via interaction with myosin
Form cleavage furrow during cytokinesis
Microtubules
Composed of tubulin
Create pathways for motor proteins like kinesin and dynein to carry vesicles
Found in cilia and flagella organized into 9 pairs of microtubules in a ring with 2 microtubules at the center
Connect to centrioles in centrosomes
Tubulin
Comprises microtubules
Kinesin an Dynein
Carry vesicles
Centrioles
Found in centrosomes
Organize microtubules in mitotic spindle
Intermediate filaments
Cell-cell adhesion
Maintenance of cytoskeleton
Anchor organelles
Keratin and Desmin
Keratin and Desmin
Intermediate Filaments
Epithelial Tissue
Cover body, line cavities
Protect against pathogen invasion and dessication
Simple Epithelia
One layer
Stratified Epithelia
Multiple layers
Pseudostratified Epithelia
Appear to have multiple layers, but only have one
Connective Tissue
Support body and provide framework for epithelial cells
Prokaryotes
No membrane bound organelles
Singular circular molecule of DNA concentrated in nucleoid region
Stroma
Support structure of an organ
Archaea
Extremophiles, use alternative energy sources
Similar to both eukaryotes and bacteria
Bacteria
Prokaryotes similar to eukarya
Eukarya
Non-prokaryotic domain
Cocci
Spherical
Bacilli
Rod
Spirilli
Spiral
Obligate Aerobes
Require O2 for metabolism
Obligate Anaerobes
Cannot surbibe in O2 containing environments, can only carry out anaerobic metabolism
Facultative Anaerobes
Can survive w/ and w/o O2 toggling between metabolic pathways
Aerotlerant Anaerobes
Cannot use O2, but can survive in O2
Enevelope
Cell wall and cell membrane of bacteria
Gram-Positive
Turn purple when stained with crystal violet
Thick cell wall of peptidoglycan and lipoteichoic acid
Gram-Negative
Turn pink-red when stained with crystal violet
Thin cell wall with peptidoglycan and outer membrane of lipopolysaccharides
Chemotaxis
Movement of bacteria in response to stimuli
Flagella
Flagellin filament anchored by basal body and hook
Prokaryotic Ribosomes
Smaller than Eukaryotic ribosomes
Prokaryote Energy
Electron Transport chain in cell membrane
Binary Fission
Prokaryotic reproduction
Chromosome replicates while cell grows in size until the cell wall begins to grow inward along the midline of the cell and it divides into two identical daughter cells
Plasmid
Extrachromosomal genetic material found in prokaryotes
Virulence Factor
Antibiotic resistance genes
Episomes
Plasmids that can integrate into the genome
Transformation
Acquisition of genetic material from the environment
Conjugation
Transfer of genetic information from one bacterium to another across a conjugation bridge
Transduction
Transfer of genetic material from one bacterium to another via bacteriophage as a vector
Transposons
Genetic elements that can insert into or remove themselves from the genome
Bacterial Growth
Lag Phase
Log Phase
Stationary Phase
Death Phase
Lag Phase
Bacteria adapt to new local conditions
Log Phase
Growth increases exponentially
Stationary Phase
Growth levels off as resources are reduced
Death Phase
Death of bacteria as resources become insufficient
Capsid
Protein coat of a virus
Virus
Consists of genetic material, a capsid, and a lipid containing envelope
Virion
Individual virus particles
Bacteriophage
Viruses that target bacteria
Tail Sheath
Injects genetic material into bacterium
Tail Fibers
Allow the bacteriophage to attach to the host cell
Viral Genomes
Composed of DNA or RNA, Single or Double stranded, positive sense or negative sense
Positive Sense
Can be directly translated
Negative Sense
Complementary strand must be produced by RNA Replicase
Retroviruses
contain single stranded RNA to which complementary DNA is made using reverse transcriptase
Extrusion
Lysis of host cell by virus to release viral progeny
Lytic Cycle
Bacteriophage produces massive number of new virions until cell lyses
Virulent
Lysogenic Cycle
Virus integrates into host genome to be reproduced along with cell which enters lytic cycle later on
Prions
Infectious proteins that trigger misfolding of other proteins, usually converting alpha helices to bet pleated sheets
Viroids
Plant pathogens
Small circles of complementary RNA that turn off genes