Biology Flashcards
4 tenets of Cell Theory
1) All living things composed of cells
2) Cell is basic functional unit of life
3) Cells only arise from preexisting cells
4) Cells carry genetic info in the form of DNA
Lysosomes
Contain hydrolytic enzymes that can break down substances ingested by endocytosis and cellular waste products
Rough ER
Studded w/ ribosomes; permit translation of proteins destined for secretion
Smooth ER
Lipid synthesis and detoxification
Peroxisomes
Contain hydrogen peroxide; can break down very long chain fatty acids via beta-oxidation
Microfilaments composed of
actin
Microtubules composed of
tubulin
Intermediate filaments
Involved in cell-cell adhesion and maintenance of integrity if cytoskeleton
Epithelial cells form the
parenchyma
Connective tissues form the
stroma/support structure; secrete materials to form an extracellular matrix
Archaea
Live in harsh environments; use chemical sources of energy; have single circle chromosome and divide via binary fission; have histones and similar RNA polymerases to eukaryotes
Bacteria
Have cell walls, lack organelles; classified by shape (cocci, bacilli, spirilli), metabolic process (aerobes, anaerobes)
Eukarya
Have nucleus, membrane bound organelles, may form multicellular organisms
Plasmid
Extrachromosomal material in bacteria that can contain antibiotic resistance genes (virulence factors)
Bacterial genetic recombination
increases bacterial diversity
Transformation
Genetic material from surroundings is taken up into cell, which can incorporate into the genome
Conjugation
Transfer of genetic material from one bacterium to another across a conjugation bridge
Transduction
Transfer of genetic material from one bacterium to another via a bacteriophage vector
Transposons
Genetic elements that can insert into or remove themselves from the genome
Virus structure
Composed of genetic material (circular, linear, single or double stranded DNA or RNA) + protein coat (capsid). Sometimes surrounded by an envelope containing lipids
Lytic cycle
Bacteriophage maximizes use of cells machinery w/ little regard for survival of host cell. Host is swollen w/ virions, cell lyses, and other bacteria can be infected. Virus in lytic phase = virulent
Retrovirus
Enveloped, single-stranded RNA virus; carries the enzyme reverse transcriptase
Lysogenic cycle
If virus does not lyse the bacterium and integrates into host genome as a provirus or prophage; virus is replicated as bacterium reproduces
