Cell structures and metabolism Flashcards
organisms with NO distinct nuclear compartment to house their DNA
prokaryotic
2 major classes of prokaryotic organisms
bacteria (eubacteria)
archaea
3 major divisions of the living world
bacteria (eubacteria)
archaea (archabacteria)
eukaryotes
organisms that house their DNA in a distinct, sub-cellular compartment (nucleus)
eukaryotic
Is bacteria single or multi celled?
single
Is archaea single or multi celled?
single
Are eukaryotes single or multi celled?
mostly multi
yeast is single-celled
complex, organized, multi-celled organisms with plasma membranes, membrane-bound organelles, DNA, RNA, ribosomes
eukaryotes
this type of cell has genetic information (DNA) that is stored as chromosomes in membrane-bound nucleus
eukaryotic cells
single-celled organisms; simple; contents are part of cytoplasm, not separated by membrane
prokaryotic cells
organelle with selective barrier and enables cells to maintain integrity to function as a coordination chemical system
plasma membrane
organelle that is the “store-house” of genetic information
nucleus
lipid and protein biosynthesis and intracellular Ca2+ store (organelle)
ER
membrane bound ribosomes which allows for co-translational translocation of protein peptides chains into the ER concomitant with protein synthesis (organelle)
Rough Er
regions of ER that lack ribosomes (organelle)
Smooth ER
regions of smooth ER from which transport vesicles bud off and carry newly synthesizes proteins and lipids to the Golgi (organelle)
Transitional ER
In cells that specialize in lipid metabolism, the synthesis occurs in the __ ER.
smooth
In muscle cells, the expanded smooth ER is specialized for Ca2+ storage and is called the ____.
sarcoplasmic reticulum
major site of carbohydrate synthesis, sorting, and dispatching of products made in the ER
Golgi
Energy metabolism (oxidative phosphorylation and Krebs cycle)
mitochondria
also has distinct mitochondrial DNA genome separate from nuclear DNA
site of intracellular digestion of macromolecules
very heterogeneous in terms of morphology
hydrolytic enzymes in these are all acid hydrolases
lysosomes
organelles in eukaryotic cells
plasma membrane
nucleus
ER (rough and smooth
prokaryotes: cell membrane? nucleus? chromosomes? ER? vesicles? Golgi? Mitochondria? cytoskeleton? ribosomes? size?
yes no 1 (not true chromo) no yes no no yes/no yes (smaller) 1-10 microns
eukaryotes: cell membrane? nucleus? chromosomes? ER? vesicles? Golgi? Mitochondria? cytoskeleton? ribosomes? size?
yes yes many yes yes yes yes yes yes (larger) 10-100 microns
key structures in bacteria
fimbriae (or pili)
flagella
LPS
capsule
function of fimbriae (pili)
attachement to surfaces
function of flagella
motility
function of lipopolysaccharides (LPS)
activate inflammatory response
function of capsule
may play role in dental caries
Which bacterial cell wall appears blue/purple?
Gram positive
Which bacterial cell wall appears pink/red?
Gram negative
What causes the gram positive bacteria to appear purple/blue?
thick peptidoglycan layer (cell wall)
prevents crystal violet from being washed out
Which bacterial cell wall has an inner and outer membrane?
Gram negative
gram + has an inner membrane but no outer membrane
Teichoic acids are found on gram positive or negative bacterial cell walls?
positive
LPS is found on the outer membrane of gram positive or negative bacterial cell walls?
negative
What is the enzyme that is responsible for the crosslinking in peptidoglycan?
transpeptidase
Transpeptidase is inhibited by which antibiotic?
ampicillin
Peptidoglycan is comprised of chains of alternating ___ and ___ sugars.
N-acetylmuramic acid (NAM)
N-acetylglucosamine (NAG)
Peptidoglycan chains are cross-linked by ____.
oligopeptides
What does a eukaryotic cell membrane consist of?
lipid bilayer
proteins (ex: transmembrane, inner and outer proteins)
has membrane bound organelles
site of oxidative phosphorylation and major ATP production within the cell
contain small, circular genome
mitochondria
Where in the mitochondria does oxidative phosphorylation occur?
inner mitochondrial membrane
Where does glycolysis occur?
cytoplasm
What does glycolysis generate in the cytoplasm?
pyruvate
In anaerobic conditions, pyruvate will be converted into ___.
lactic acid
In aerobic conditions, pyruvate will enter the ___.
krebs cycle
Where does the krebs cycle occur?
mitochondrial matrix
What needs to be transported into the mitochondrial matrix for the krebs cycle?
pyruvate
How does pyruvate cross the outer mitochondrial membrane?
voltage-gated anion channels
What is pyruvate converted into in the mitochondrial matrix?
Acetyl-CoA
What converts pyruvate into acetyl-CoA?
pyruvate dehydrogenase complex
Acetyl-CoA transfers its acetyl group to ___ to form ___ which begins the Krebs cycle.
oxaloacetate
citrate
What is oxidative phosphorylation?
ADP–> ATP
What is the ETC?
NADH releases high energy electrons to form NAD+ and H+; electrons then drive process of pumping hydrogen ions (protons) from matrix to intermembrane space
What brings H+ back into matrix from the intermembrane space to produce ATP from ADP?
ATP synthase
What are the two processes dealing with the Krebs cycle and respiration?
ETC
oxidative phosphorylation
In oxidative phosphorylation, each H+ that is pumped through the channel can generate __ molecule of ___.
1
ATP
What is a better source of fuel: glucose or fatty acid? why?
fatty acid
generate more NADH (31>8)
What is the net yield of glycolysis in terms of ATP and NADH?
2 ATP
2 NADH
How many ATP, NADH, and FADH2 does the citric acid cycle produce?
2 ATP
8 NADH
2 FADH2
A molecule of glucose can produce how many net ATP molecules?
30-32
What is a cooperating community of microorganisms within a matrix that is attached to a surface?
biofilms
Where do biofilms develop?
any fluid-filled environment containing microorganisms that are subjected to stress or fluid flow
Where are dental biofilms found?
tooth surfaces
mucosal surfaces of the oral cavity
What is formed on a tooth immediately even after brushing?
pellicle
What attaches to a pellicle on the tooth?
largely gram + cocci and rods (seconds)
What does the pellicle form from?
proteins in the salvia or GCF
What is the function of the pellicle?
serves as a conditioning film for attachment of the initial colonizing bacteria
How do bacteria within micro-colonies communicate with each other?
chemical signals
What is the purpose of micro-colonies being porous?
have fluid channels that allow for the movement of nutrients, waste products, metabolites, enzymes, and O2
Cariogenic bacteria produce extracellular polysaccharides from ___.
sucrose
What makes up sucrose?
glucose
fructose
Glucose can be built into homopolymers of glucose called ___.
glucans
(mutan –> water insoluble)
(dextran –> water-soluble)
Fructose can be built into homopolymers consisting of beta 1,2 and beta 2,6 linkages called ___.
fructans
What is the function of the extracellular polysaccharides from sucrose?
nutritional source for bacteria which supports further adhesion and subsequent accumulation of plaque
Sucrose is (highly/poorly) soluble and diffuses (rapidly/slowly) into the plaque biofilm where it serves as a ___ for production of the extracellular polysaccharides and acids.
highly
rapidly
substrate
What are the main causal agent for caries?
streptococcus mutans
lactobacillus casei
lactobacillus fermentum
(Saccharolytic/Asaccharolytic) bacteria derive their energy from glycolysis.
saccharolytic
Acid produced from ___ bacteria causes caries.
saccharolytic
Biofilms on the tooth surfaces will form a dental ___.
plaque
Once a dental plaque becomes calcified it is called ___.
calculus (tartar)
Most healthy dentition and no periodontal disease have bacteria in the biofilms that are mostly gram __.
positive
Gram positive bacteria mainly ferment ____ to a final end product of _____.
sugars lactic acid (saccharolytic)
Production of lactic acid results in (low/high) pH, which results in demineralization of tooth enamel and dentin resulting in caries.
low
Where do asaccharolytic bacteria derive their energy from?
amino acids
Free amino acid can be. ___ and ___.
deaminated
reduced
What are the constituents of dental plaque?
ammonium acetate
ammonium propionate
ammonium butyrate
Dental calculus further promotes (a/saccharolytic) fermentation.
asaccharolytic
What causes oral malodor that is associated with periodontal disease?
cysteine and methionine ferment to produce hydrogen sulfide
What are the types of saliva?
serous
mucos
mixed
main product of the parotid glands
serous saliva
main product of the minor glands
mucos saliva
main product of sublingual and submandibular glands
mixed saliva
What makes up 99% of saliva?
water
Functions of saliva
lubricate and protect buffering action and clearance maintenance of tooth integrity antibacterial activity taste and digestion saliva production up to 1L/day
What is secreted into the gingival sulcus?
gingival crevicular fluid (GCF)
functions of GCF
cleansing sulcus
improve adhesion of epithelium to tooth
antimicrobial properties
antibody defense of gingiva
What kind of environment does the GCF provide?
rich in proteins (asacharolytic)
fermentation of AA to produce ammonia
Is the pH of GCF high or low and what is the purpose?
high
prevent dental caries from developing
What is the downside to high pH of GCF?
lead to precipitation of calcium and phosphate on dental biofilm (plaque) and eventually formation of calculus
Asaccharolytic bacteria produces low or high pH?
high
Which bacteria would ampicillin mainly kill?
gram +
bc of peptidoglycan
thin protein layer that forms on the surface of the enamel by binding of glycoproteins present in saliva.
pellicle
organisms (bacteria) that metabolize sugars to derive energy
saccharolytic bacteria
Soft biofilm that builds up on the teeth due to the attachment of bacteria to the tooth surface.
plaque
Harden form of plaque (often called tartar) that builds up on teeth due to the deposition of minerals into the plaque.
calculus
metabolic pathway used by cells to breakdown glucose to produce ATP energy and pyruvate, which can then be shuttled into the Krebs cycle.
glycolysis
metabolic pathway that cells use to breakdown fatty acids into Acetyl-CoA, which can enter into the Krebs cycle to produce energy.
beta-oxidation
also known as the Citric Acid cycle or the TCA cycle is a series of enzyme catalyzed chemical reactions that release stored energy by the oxidation of Acetyl-CoA.
krebs cycle
occurs in the inner mitochondrial membrane and involves a series of reactions that shuttle electrons from NADH and FADH2 to molecular oxygen. This results in the pumping of protons from the mitochondrial matrix into the mitochondrial intermembrane space and oxygen is reduced to form water. The H+ ions (protons) are pumped into the mitochondrial matrix through the ATP synthase enzyme, which uses the force of H+ ions flowing through it to phosphorylate ADP making ATP.
electron transport
The dental pellicle forms within (seconds/hours) after cleaning the teeth by the association of _____ in the salivary with the enamel surface.
seconds
proteins
The pellicle serves as a further attachment matrix for oral bacteria, which produce a dental _____(plaque).
biofilm
Further mineralization of plaque leads to the formation of _______.
calculus
Bacteria metabolism within the dental biofilms produces ____ ___ and other end-products that contribute to the development of caries.
lactic acid
What has provided us with a wealth of resources and information so that we can now consider the practice of personalized dentistry based upon knowledge of an individual’s genetics and the biomes of the bacteria that colonize the oral cavity?
modern molecular biology
