Unit 1: Chapter 3 Flashcards
Robert Hooke
- 1st to use the term cells
- described the small chambers within cork
Matthias Schleiden
- botanist who observed plant tissue and described them being composed of cells
- thought cells divided through crystallization instead of cell division
Theodor Schwann
- observed animal tissue
- realized that plant and animal tissues are similar
- cells are important in plant and animal tissue
Robert Remak
- came up with modern cell theory
- cells come from other cells through cell division
- before Virchow
Rudolf Virchow
- published cellular pathology essays
- cell theory became popular through Latin phrase all cells arise from cells
- father of pathology
Key components of Cell Theory
- All living things are made of cells
- The cell is the basic unit of life
3 all new cells arise from existing cells
Key points of Endosymbiotic Theory
Mitochondria and chloroplasts coming me from prokaryotic cells who have a symbiotic relationship with a eukaryotic host
Evidence:
1. Mitochondria/chloroplast dna/structure similar to bacteria
2. Mitochondria/chloroplast ribosomes similar to bacteria
3. Mitochondria/chloroplast similar to binary fission of bacteria instead of mitosis of eukaryotes
Miasma theory
Disease comes from decomposing matter, found in sewage/cesspits
Germ Theory of Disease
Diseases may result from microbial infection
Ignaz Semmelweis
-washing hand between examining patients helped prevent infection
John Snow
- first known epidemiological study: tracked the source of cholera outbreaks to drinking water
- first public response to an epidemic
Snow and Semmelweis
-disease is not only transmitted through the air but also through contaminated items
Louis Pasteur
- airborne microbes caused food spoilage not spontaneous generation
- if microbes caused food spoilage they also could cause infection
Joseph Lister
- implemented phenol spray to disinfect during surgery to reduce post surgery infection
- standard medical practice
Robert Koch
- Koch’s postulates
- established protocol to determine the cause of an infectious disease
Prokaryotic cell characteristics
- no nucleus instead nucleoid
- 1 single circular chromosome found in nucleoid
- domains: Archaea and Bacteria
- no membrane bound organelles
- capsule
Prokaryotic cell morphologies
- Coccus: round
- Bacillus: rod
- Vibrio: curved rod
- Coccobacillus: short rod
- Spirillum: spiral
- Spirochete: loose spiral
Prokaryotic Cell Arrangements
- Coccus: single circle
- Diplococcus: pair of cocci
- Tetrad: Group of four cells in a square shape
- Streptococcus: chain of cocci
- Staphylococcus: cluster of cocci
- Bacillus: single rod
- Streptobacillus: chain of rods
How do prokaryotic cells maintain their morphology?
-cell wall protects from changes in osmotic pressure
Isotonic medium
-solute concentrations inside and outside of the cel are equal
Hypertonic medium
-solute concentration outside the cell is greater than inside so water diffused out of cell
Hypotonic medium
Solute concentration inside the cell is greater than outside
-water moves into the cell, cell can burst
Crenation
-cell is dehydrated/shriveled
Plasmolysis
Plasma membrane detached from cel wall, cell wall remains intact so cell can maintain shape/integrity
Plasmids
- in prokaryotic cells
- carry genes that help survive: antibiotic resistance/advantageous traits
Prokaryotic Ribosomes
-have a size of 70s
Inclusions
- in prokaryotic cells
- ability to store nutrients or used in metabolism/chemical process
Vegetative cells
- sensitive to extreme temps/radiation
- gram positive
- normal water/enzymatic activity
- active growth & metabolism
Endospores
Structures that protect bacteria when conditions are unfavorable, can germinate and turn back into vegetative cells
- resistant to temp/radiation
- does not absorb gram stain
- dehydrated/ no metabolic activity
- dormant/no growth
Peptidoglycan
- cell wall is made of this
- only in bacteria
- gram positive: thick layer
- gram negative: thin layer
Mycolic acid
- eternal waxy layer in cell wall
- acid fast stain
Pseudopetidoglycan
-found in archaea
Bacterial membrane
- made of phospholipids w/ integral/peripheral proteins
- fatty acids are ester linked
- Archaea are ether linked
Glycocalyx
- a sugar coat
- either capsule(organized/tight)or slime(less organized/loose) layers that help attach to surfaces or evasion of host immune system
S-layer
-cell envelope in bacteria is outside acts as a cell wall in archaea
Fimbriae
Short bristle proteins that stick out of cell surface to help attach to things
Pili
Longer less numerous protein that stick out and help attach to surfaces
F pilus/sex pilus
Important in the transfer of DNA between bacteria
Flagella
Help cells move in aqueous environments
Basal body
Motor of the flagellum embedded into plasma membrane
Chemotaxis
-bacteria moves in response to chemicals like food or away from a repellent
Monotrichous flagellum
Singular flagellum at one end of the cell (polar)
Amphitrichous flagellum
Have a bunch of flagellum at each end
Lophotrichous flagella
Have a bunch of flagella at one end of the cell
Peritrichous flagella
Flagella that cover the entire surface of the cell
Eukaryotic cell characteristics
- have a nucleus w/ a complex nuclear membrane (has 2 lipid bilayers)
- membrane bound organelles
- cytoskeleton
- multiple rod shaped chromosomes
- domain: Eukarya
Nucleolus
-site of ribosomal synthesis
Eukaryotic ribosomes
- in mitochondria and chloroplasts size 70s
- in rough ER size is 80s
Endomembrane System
- eukaryotic cells
- contains transport membrane bound organelles (vesicles, endoplasmic reticulum, Golgi apparatus)
Golgi apparatus
Modified lipids and proteins transported from ER
Smooth endoplasmic reticulum
- lipid biosynthesis
- carbohydrate metabolism
- detoxifies compounds
Cytoskeleton
Provides support/ network for transport of intracelular materials
- Microfilaments
- intermediate filaments
- microtubules
Centrosomes
-forms spindles in mitosis
Mitochondria
Site of cellular respiration
-2 membranes outer and inner w/ cristae
Endocytosis
Take material into the cell
Exocytosis
Expel matter from cell
Difference between plasma membrane of eukaryotic and prokaryotic
-eukaryotic have sterols, glycoproteins/glycolipids, that help cells recognize good and bad cells
Difference between eukaryotic and prokaryotic flagella
- eukaryotic has a more flexible flagella that whips instead of rotating
Why are prokaryotes ubiquitous
- are extremely resilient and adaptable
- metabolically flexible, can switch drone 1 energy source to another
Community
-prokaryotes live in a group that interact w/ each other and hosts (including humans)
