Functional Anatomy of Prokaryotes and Eukaryotes Flashcards
What are the two characteristics of a prokaryote?
DNA not enclosed in a membrane (one circular chromosome) and no membrane bound organelles
What are the two characteristics of a eukaryote?
DNA is enclosed in a membrane (multiple chromosomes) and membrane bound organelles
What are the four shapes of prokaryotes?
Cocci (round) , Bacillus (rod), Spiral (vibrio, spirillium and spirochete) and pleomorphic
What is diplococci?
pair of cocci
What is streptococcus?
chain of cocci
What is a tetrad?
cluster of 4 cocci
What is a sarcina?
cubical packet of 8 cocci
What is staphylococcus?
grape-like bunches
What is diplobacillus?
pair of bacilli
What is Streptobacillus?
chain of bacilli
What is Pallisades?
bacilli connected in parallel with each other
What are the 5 external appendages of a prokaryote?
Glycocalyx, flagella, axial filaments, fimbriae and pili
What is the glycocalyx?
layer of material covering the cells
What are the two types of glycocalx?
Capsule and slime layer
How is a capsule attached?
organized and firmed attached
How is the slime layer attached?
unorganized and loosely attached
What is the glycocalyx composed of?
polysaccharides and glycoproteins (Some polypeptides)
What are the four functions of the glycocalyx?
adhesion to surfaces, osmotic barriers, protect bacteria from phagocytosis and storage or nutrients
What is flagella?
long filamentous appendages that rotate to propel bacteria
What are flagella composed of?
filament, hook, basal body
What is a filament?
flagellin protein arranged in helix
What does a basal body do?
anchors flagella to the cell
What is the function of flagella?
motility and taxis
What does monotrichous mean?
one flagellum
What does Lophotrichous mean?
several flagella at one pole
What does Amphitrichous mean?
flagella at both poles
What does Peritrichous mean?
flagella all over the cell
What does Taxis mean?
moving toward or away from a substance
What does it mean when the flagella spin counterclockwise?
they are running (moving forward)
What does it mean when the flagella spin clockwise?
it is tumbling (cell changes direction)
Attractants cause flagella to spin ____.
counterclockwise
Repellants cause flagella to spin ____.
clockwise
What are axial filaments?
bundles of fibrils that wrap around the cell wall of spirochetes
What is the function of axial filaments?
corkscrew motion motility
What are fimbriae?
several short hair-like projections
What is the function of fimbriae?
surface adhesion
What are pili?
one or two longer hair-like projections
What are the two functions of pili?
motility and sexual-conjugation
What is sexual conjugation?
pili forms tubes for transferring genetic material
What are cell walls composed of?
peptidoglycan
What is peptidoglycan composed of?
Disaccharides (NAG and NAM)
What are the sheets of peptidoglycan linked by?
polypeptides
What are the three functions of the cell wall?
maintains shape of cell, physical protection and enables cell to escape rupture in hypotonic environments
What are the two characteristics of a Gram (+) cell wall?
many layers of peptidoglycan and techoic acid is present
What is techoic acid composed of?
alcohol and phosphate
What are the two types of teichoic acid?
Lipoteichoic acid and wall teichoic acid
What does lipoteichoic acid do?
links to plasma membrane
What does wall teichoic acid link to?
peptidoglycan
What do the antigenic properties of bacteria cell walls do?
elicit an immune response
What is the cell wall of a Gram (-) bacteria like?
Few layers of peptidoglycan (in periplasm) and no teichoic acid
What does the outer membrane of a Gram (-) cell like?
protection of antibiotics and phagocytes; contains lipopolysaccharides
What three things are found in lipopolysaccharides?
Lipid A, Core Polysaccharides and O Polysaccharides
Where is Lipid A found?
embedded in outer membrane
What is the function of Core polysaccharides?
structural stability
What is the function of O polysaccharides?
antigenic
What is the periplasm?
the space between two membranes
What are the two types of Atypical Cell Walls?
Acid-fast Bacteria and Mycoplasmas
What do acid-fast bacteria contain in their cell wall?
mycolic acid
What is mycolic acid like?
a waxy lipid
What does mycolic acid prevent?
dessication and digestion from phagocytes
What are two examples of acid-fast bacteria?
Mycobacterium and Nocardia
What do mycoplasmas lack?
cell walls
What do mycoplasmas contain in their membrane?
cholestrol
What is an exmaple of a mycoplasma?
Mycoplasma pneumoniae
What are the three characteristics of the plasma membrane?
Phospholipid bilayer, contains proteins and dynamic
What are the names of the two proteins found in the plasma membrane?
peripheral and Integral
Were are peripheral proteins found?
inner or outer surface of membrane
Where are integral proteins found?
embedded in membrane
What does transmembrane mean?
penetrate membrane completely
What are the two functions of the plasma membrane?
Selective permeability and enzymes for ATP production
What is selective permeability?
regulates movement of molecules in and out of the cell
What is simple diffusion?
movement of a solute from high concentration to low concentration
What is facilitated diffusion?
transporter protein facilitates movement of a solute from high concentration to low concentration
What is Active transport?
transporter protein and ATP required to move solutes from low concentration to high concentration
What is osmosis?
movement of water across semipermeable membrane from high concentration to low concentrations of water
What is a hypotonic solution?
the concentration outside of the cell is less than the concentration inside the cell
What is an isotonic solution?
Concentration outside of the cell is equal to the concentration inside of the cell
What is a hypertonic solution?
the concentration outside of the cell is greater than the concentration inside of the cell
What are the 6 internal structures of a cell?
- cytoplasm 2. nucleoid 3. ribosomes 4. plasmids 5. inclusions 6. endospores
What is the cytoplasm?
viscous semi-fluid substance of the cell
What is the function of the cytoplasm?
site of enzymatic reactions
What is a nucleoid?
single chromosome, circular dsDNA; contains genetic information for cell structures and functions
What are ribosomes?
granules scattered throughout cytoplasm
What is the structure of ribosomes?
protein and rRNA subunits
What are the sizes of subunits?
small subunit (30s); large subunit (50s)
What is the function of ribosomes?
assemble amino acids into polypeptides
What are plasmids?
self replication small circular dsDNA
What are the two functions of plasmids?
- antibiotic resistance 2. carry additional genes
What are cytoplasmic inclusions?
accumulated stored materials
What are metachromatic reserves?
phosphate reserves
What are polysaccharide granules?
energy reserves
What are lipid inclusions?
energy reserves
What are sulfur granules?
energy reserves
What is the function of gas vacuoles?
maintain buoyancy
What are magnetosomes?
orient bacteria, hydrogen peroxide protection
What are endospores?
highly resistant dormant structure produced by certain bacteria
What is the structure of endospores?
- thick peptidoglycan between TWO membranes 2. spore coat cover containing keratin
What two Genuses are involved with endospores?
Bacillus and Clostridium
When are endospores formed?
During times of low nutrients and harsh environments
What are endospores resistant to?
heat, desiccation, toxic chemicals, UV and radiation
What is the process of sporulation?
- spore septum forms, isolating DNA and small amount of cytoplasm 2. Plasma membrane engulfs isolated DNA and cytoplasm forming a foreshore 3. Peptidoglycan forms between two membranes 4. keratin spore coat forms 5]. endospore is released
What does germination require?
water, nutrients
What is the process of germination?
- free spore absorbs water 2. metabolism resumes 3. free spore swells, ruptures and releases one vegetative body
What are the four parts of the cell structure in eukaryotes?
- external appendages 2. cell wall 3. plasma membrane 4. internal structures
What are the two external appendages found in eukaryotes?
flagella and cilia
Flagella are ____ while cilia are ____.
long,short
What are flagella and cilia composed of?
microtubules made of tubulin protein
How do flagella and cilia move?
in a wave- like manner
What are the functions of flagella and cilia?
motility and move substances along surface of cell (cilia)
What is the cell wall of algae made of?
cellulose
What is the cell wall of fungi made of?
chitin
What is the cell wall of protozoa and helminths made of?
lack cell wall
What are the two characteristics of the plasma membrane in eukaryotes?
- similar to prokaryotes 2. differs i types of proteins found on membrane
What are the two types of endocytosis?
phagocytosis and pinocytosis
What is phagocytosis?
“cell eating”. projects pseudopods, engulfs particles
What is pinocytosis?
“cell drinking”. folds inward, bring in fluid
What is exocytosis?
vacuoles fuse with plasma membrane to expel
What are the three internal structures found in eukaryotes?
cytoplasm, ribosomes and membrane-bound organelles
What are the two parts of the cytoplasm?
cytosol and cytoskeleton
What is cytosol?
fluid portion
What is cytoskeleton?
proteins that support shape and assist in substances through the cell
What are the three types of cytoskeleton?
microfilaments, intermediate filaments and microtubules
What are ribosomes?
granules scattered free in cytoplasm, or on surface of ER
What is the structure of ribosomes?
protein and rRNA subunits
What are the rRNA subunits of ribosomes?
small subunits (40s), large subunits (60s)
What is the function of ribosomes?
assemble amino acids into polypeptides
What are membrane-bound organelles?
specialized structures that perform specific functions; contained in a membrane
What are the seven membrane bound organelles?
nucleus, endoplasmic reticulum, golgi complex,, lysosomes, mitochondria, chloroplasts, peroxisomes
What is the structure of the nucleus?
nuclear envelope: two lipid bilayers with pores, round or oval
What two structures are found in the nucleus?
nucleolus and chromosomes
What is the nucleolus?
condensed region of DNA —> rRNA synthesis
What are chromosomes?
DNA wrapped around histone proteins, supercoiled
What is the structure of endoplasmic reticulum?
network of cisternae
What are cisternae?
flattened membranous sacs
What are the two types of endoplasmic reticulum?
Rough ER and Smooth ER
What does rough er have that smooth er lacks?
ribosomes
What is the function of rough er?
synthesize secretory and membrane proteins
What is the function of smooth er?
synthesize lipids, detoxification
What is the structure of the golgi complex?
cisternae stacked on one another
What is the function of the golgi complex?
receive and modify proteins from the ER
What is the store of lysosomes?
membrane enclosed sac of hydrolytic enzymes
What are the three functions of lysosomes?
digesting phagocytize materials, recycling cells organic materials, apoptosis
What is apoptosis?
programmed cell death
What is the structure of mitochondria?
rod shaped, double membrane (inner and outer), inner membrane contains folds called cristae, contains its own 70s ribosomes and DNA
What is the function of mitochondria?
cellular respiration and ATP synthesis
Where are chloroplasts found?
algae and plants
What is the structure of chloroplasts?
double membrane, grana, contains its own 70s ribosomes and DNA
What is grana?
stacks of thylakoids
What are thylakoids?
flattened membrane sacs containing chlorophyll
What is the function of chloroplasts?
photosynthesis —> glucose synthesis
What is the structure of peroxisomes?
small membrane bound sacs containing catalase
What is the function of peroxisomes?
decomposes toxic hydrogen peroxide
What is the endosymbiosis theory?
organelles evolved from symbiotic prokaryotes living inside other prokaryotes
What is the evidence of endosymbiosis theory?
mitochondria and chloroplasts have double membranes, 70s ribosomes and separate self-replicating DNA