Biology: Chapter 1: The Cell Flashcards
What are the tenets of Cell Theory
1) All living organisms are made up of cells
2) Cells are the basic functional unit
3) Cells are made from pre-existing cells
4) Cells contain genetic information in the form of DNA
Why are viruses not considered living organisms?
Viruses violate tenets 3 and 4 of the cell theory: They cannot reproduce alone (require the host cell) and they do not have DNA
What are Eukaryotic cells
Cells with a nucleus, membrane bound organelles, and unicellular/multicellular
What is the cytosol
fluid that suspends the organelles and allows for diffusion of molecules throughout the cell
what is the nucleus
contains DNA in the form of chromosomes; surrounded by nuclear envelope; site of transcription
what are nuclear pores
pores in the nuclear envelope that allow for two-way exchange of materials between the nucleus and the cytosol
what is the nucleolus
subsection of nucleus where RNA is synthesized (transcription)
what is the mitochondria
powerhouse of the cell; divide independently via binary fission; trigger apoptosis by releasing mitochondrial enzymes
what are lysosomes
Contain hydrolytic enzymes to break down molecules ingested by endocytosis; autolysis happens if these enzymes are released into cytosol
what is the rough endoplasmic reticulum
contains ribosomes; site of protein synthesis
what is the smooth endoplasmic reticulum
lipid synthesis; detoxication;
moves proteins from RER -> Golgi Apparatus
what is the Golgi Apparatus
modifies, packages, and secretes proteins
what are peroxisomes
contains H2O2; breaks down fatty acid chains via beta oxidation; lipid synthesis; contribute to pentose phosphate pathway
what are the components of the cytoskeleton
microfilaments
microtubules
intermediate filaments
what are microfilaments
made up of actin; provide structural protection for the cell and cause muscle contraction when interacting with myosin; formation of cleavage furrow during mitosis
what are microtubules
made up of tubulin; create pathways for vesicle movement; make up cilia and flagella
what is the 9 + 2 arrangement for flagella
9 outer microtubules and 2 center microtubules
What are intermediate filaments
cell to cell adhesion and maintenance of the integrity of cytoskeleton; anchor organelles; examples keratin and desmin
what is epithelial tissue
cover the body and line cavities; protect against pathogen invasion; absorb/secrete substances; participate in sensation; parenchyma; polarized (inner lumen and outer membrane)
what are the classifications of epithelial tissue
simple –> one layer
stratifies –> multi-layer
pseudo stratified –> looks like multiple layers but is one
what are the types of epithelial tissue shapes
cuboidal –> cubed
columnar –> long and narrow
squamous –> flat and scale like
what is connective tissue
support the body and provide framework for epithelial cells; stroma; secrete materials to form extracellular matrix
what are the types of connective tissue
bone, cartilage, tendons, ligaments, adipose tissue, and blood
what are prokaryotic cells
do not contain membrane bound organelles, nucleus, or mitochondria; single circular DNA located in nucleoid region; ETC using cell membrane; ribosomes are smaller (30s and 50s)
what are the three domains of life
archaea, prokaryotes, eukaryotes
What are archaea
Often extremophiles that use chemical sources of energy
how are archaea similar to eukaryotes
start translation with methionine; similar RNA polymerases; DNA histones
How are archaea similar to prokaryotes
single, circular DNA; divide by binary fission; no membrane bound organelles/nucleus
what are the classifications of bacteria
Cocci –> Circular
Bacilli –> Rod-like
Spirilli –> Spiral
What is an obligate aerobe
survives and uses oxygen for metabolic processes
what is an obligate anaerobe
cannot survive in oxygen and does not use it for metabolic purposes
what is a facultative anaerobe
can survive in oxygen containing environments; can use/not use oxygen for metabolic processes
what is an aero-tolerant anaerobe
can survive in an oxygen containing environment but does not use oxygen for metabolic processes
What is a gram positive bacteria
Contain peptidoglycan and lipoteichoic acid in cell wall
What is a gram negative bacteria
Thin cell wall with little peptidoglycan and an outer membrane of phospholipids and lipopolysaccharides
what are flagella
generate propulsion to move toward or away from chemical stimuli (chemotaxis)
what is the difference between bacterial flagella and eukaryotic flagella
Bacteria –> flagellin make up basal body, filament and hook
Eukaryote –> 9 outer microtubules and 2 inner
what is binary fission
chromosome replicates, cell grows in size until cell wall grows inward along midline (invagination) then divides into two daughter cells
what are plasmids
contain extrachromosomal material that can be integrated into genome (episomes)/transferred; can contain virulence factors
what are the kinds of genetic recombination
transformation, conjugation, transduction, transposons
what is transformation
genetic material from surroundings is taken up by a cell which can be incorporated by genome
what is conjugation
transfer of genetic information across a conjugation bridge (sex pillus); transferred from F+ to F- cells
what is transduction
genetic information passed through bacteriophages
what is a transposons
genetic elements that can insert or remove themselves from genome
what is the bacterial growth pattern
lag phase, exponential phase, stationary phase, death phase
what is the structure of a virus
genetic material surrounded by a capsid (protein coat) and sometimes a lipid containing envelope
why is a virus called an obligate intracellular parasite
viruses cannot survive and replicate outside of a host cell
what is a tail sheath
structure of bacteriophage that injects genetic information into a bacterium
what are tail fibers
structure of bacteriophage that allow attachment to host cell
What is a positive sense single stranded RNA virus
directly translated by host genome into functional proteins
what is a negative sense single stranded RNA virus
requires complimentary strand to be synthesized by RNA replicase before translation
what is a retrovirus
single stranded RNA from which a DNA strand is made using reverse transcriptase; DNA strand is then integrated in to host genome
How are viral progeny released
cell death, lysis, or extrusion
what is the lytic cycle
viral progeny replicate until cell swells and lyses; bacteria in lytic phase are virulent
what is the lysogenic cycle
virus integrates into host genome as provirus/prophage which then reproduces along with the cell; provirus remains in genome indefinitely or leaves genome in response to stimuli and enters lytic cycle
what are prions
infectious misfolded proteins; misfolded from alpha helical to beta pleated sheets; decreases solubility and increases resistance
what are viroids
plant pathogens that are small circles of complementary RNA that can turn off genes resulting in metabolic and structural changes and potential cell death
