General Biology Flashcards
Do mature red blood cells have genetic materal?
No, but they are still eukaryotic
makes them not helpful to study genetic mutations
Endosymbiotic theory
mitochondria arose when bacteria was engulfed by another cell
What type of DNA does mitochondria have? Where does it come from?
mitochondria has circular mtDNA
comes from mother (matrilinearly)
Does the ER have a double membrane?
yes
chaperone proteins
help fold proteins in the rough ER
Smooth ER
lipid metabolism
detox (many found in liver cells)
stores Ca2+ in muscle cells
Autophagy
when lysosomes digest intracellular debris
Where do lyzosomes come from?
they pinch off the golgi body
What pH do lyzosomes have?
low pH so if their contents spill out they will not work in the cytoplasm
Peroxides
breakdown fatty acids through B-oxidation
help detox reactive oxidative species
microfilaments
part of the cytoskeleton
composed of actin polymers (protein)
work with cell movement and make the cleavage furrow
work in muscle contraction w/ myosin
Microtubules
part of the cytoskeleton
tubulin dimers
motor proteins walk along microtubules
found in flagella and cilia (only in eukaryotes)
Where are cilia located?
lungs, fallopian tubes in eukaryotes
made out of microtubules
Motor proteins
kinesin (moves up neuron axon, away from cell)
dynein (moves towards the center of the cell)
Centrosome
main MTOC
composed of 2 centrioles
separates chromosomes during division
capping proteins
can stop growing of microtubulues/microfilaments
also prevent cytoskeletal degradation
+/- ends of microtubules/microfilaments
grow at + end and shrink at - end
examples of intermediate filaments
keratin and lamin
multimeric proteins
contain two or more subunits
examples of multimeric proteins
F-actin
intermediate filaments
Difference between nucleotides and nucleosides
nucleosides don’t have a phosphate group
What is charge on phoshpate group of nucleotides?
negative
cAMP structure
one phosphate connected cycllaly to rest of nucleotide
cyclic nucleotide
How many rings do purines have?
2
How many rings do pyrimidines have?
1
Which amino acids are pyrimidines?
CUT as PY
C/U/T
Which amino acids are purines?
PUR As Gold
A/G
Which has a higher Tm A/T pairs or C/G pairs?
C/G pairs since they have 3 hydrogen bonds between them, they have a higher melting temp
What interactions are found between adjacent nucleotides?
hydrophobic interactions
Chargaff’s Rule
1:1 ratio between AT and CG
Where is 5’ end of nucleic acid?
where the phosphate group is
Melting temperature
point where 1/2 of DNA is denatured
How to denature DNA
add heat or urea
Annealing
two DNA strands come back together
Types of DNA
B-DNA: standard DNA, right-hand, 34A between groves
A-DNA: right-hand DNA but smaller groves
Z-DNA: left hand DNA
siRNA and miRNA
can inhibit gene expression by harming mRNA
hnRNA
a precursor to mRNA
Why is the genetic code degenerate?
it has multiple codons to code for a single amino acid
What are the start and stop codons?
Start: AUG (codes for Met)
Stop: UAA, UAG, UGA
meselson and stahl
determined DNA replication was semi-conservative
Differences between prokaryotic and eukaryotic DNA replication?
prokaryotes: 1 origin of replication, circular chromosome
eukaryotes: multiple origins of replication, linear DNA
Helicase
unwinds DNA
single stranded binding proteins
keep DNA separated
topiosemerase
cuts strands to relax stress / over coiling
prevents supercoiling of DNA after opened
primase
synthesizes RNA primer for polymerase to bind
DNA polymerases
synthesize DNA in 5’ to 3’ direction
read DNA in 3’ to 5’ direction
DNA ligase
connects Ozaki fragments along sugar-phosphate backbone
reverse transcriptase
synthesizes DNA from RNA
used by viruses, allows DNA to be placed in its hosts’ genome
telomerase
extends telomeres (repetitive sequences at end of chromosomes)
uses RNA template
Types of DNA polymerases in bacteria
I: Removes RNA primer, replaces primer w DNA, repairs DNA
II: repairs DNA
III: synthesizes new DNA and proofreads DNA with exonuclease activity
exonuclease activity
helps proofread newly synthesized DNA
part of DNA polymerase’s function
Leading strand
moves towards the replication fork
starts at 3’ end and moves to 5’ end at the fork
synthesizes in 5’ to 3’ direction
Lagging strand
discontinous replication
synthesizes in 5’ to 3’ direction
moving away from the replication fork towards the 5’ end away from the fork
What are histones made of?
proteins
Kinetochore
protein complexes at the chromosomal centromere
kinetochores connect two homologous chromosomes or two sister chromatids
spindle fibers connect to the kinetochore
What are spindle fibers made of?
microtubules
How many chromosomes do humans have?
46 unique chromosomes arranged into 23 pairs
What do we start mitosis with?
46 chromosomes that have been replicated to form sister chromatids. Have 46 sister chromatids
What do we start meiosis with?
23 pairs of chromosomes matched with another 23 pairs of chromosomes to make homologous chromosomes in tetrad form
gives us a total of 46 unique chromosomes
23 replicated, unique chromosomes from each parent
Nucleosomes
smaller segments of DNA organized around histones
made up of histones (protein) and DNA (nucleic acid)
H1 histone
linking protein
linker DNA
connects nucleosomes
Centromere
holds together two sister chromatids
heterochromatin
highly packaged DNA
tightly coiled
easy to see when stained
What form is DNA in during division?
heterochromatin
euchromatin
loosely packaged DNA
hard to see when stained
in this state during transcription and replication
VNTR and STR
types of segments of repeating DNA
how many repeats a person has can determine their specific DNA identity
Single nucleotide polymorphism
also known as SNiP
different nucleotides at a single location in a gene
Transposons
jumping genes
sequences can move to other parts of genome
increase diversity and help with evolution
Class 1 transposons
use copy and paste mechanism
DNA polymerase generates mRNA that codes for reverse transcriptase to make DNA strand to reinsert itself into genome
Class 2 transposons
use cut and paste mechanism
telomeres
repeating sequence on end of chromosomes
allows for wiggle room when replicating end of DNA
Autosomes
non-sex chromosomes
have 22 pairs
What type of cells do not replicate and therefore remain in the G0 phase?
neurons
Interphase
contains G1, S, G2 phases
DNA is seen as euchromatin to replicate
How many chromosomes do we have after DNA replication?
still have 46 unique chromosomes, but amount of DNA material doubled as we created sister chromatids
What is the checkpoint in the M phase?
that the spindle fibers are correctly attached
What regulates the cell cycle?
cyclin levels
What do high levels of cyclin do?
bind to specific cyclin dependent kinases (CDKs)
CDKs will phosphorylate proteins needed in that phase of the cell cycle
Do prokaryotes undergo mitosis or meiosis?
they do not undergo either
Somatic cells
body cells
What is the order of the phases of mitosis?
PMAT
nondisjunction
failure of homologous chromosomes or sister chromatids to separate, resulting in abnormal chromosome distribution
aneuploidy
incorrect number of chromosomes
Results of meiosis and mitosis
meiosis: 4 haploid, different cells
mitosis: 2 diploid, identical cells
crossing over
occurs at chiasmata when tetrad between two pairs of homologous chromosomes overlap
Where does meiosis occur?
germ cells
after what phase of meiosis are the daughter cells haploid? why?
after meiosis I
homologous chromosomes have separated. so now have 23 unique chromosomes that in the form of replicated sister chromatids
Difference between flagella of prokaryotes and eukaryotes?
eukaryotes’ flagellum are made of microtubules
What makes up microfilaments?
actin
locus
where genes are located on a chromosome
What type of genotype do carriers have?
heterozygous
hemizygous
refers to having only one copy of a gene
ex: males only have one copy of genes on the Y chromosome
Are loss of function mutations recessive or dominant?
recessive
Are gain of function mutations recessive or dominant?
dominate
Test cross
used to determine if a genotype is RR or Rr
cross with a homozygous recessive individual rr and look at outcomes
Dihybrid cross normal ratios
9:3:3:1
56% 18% 18% 6%
How can you tell if genes are linked from a dihybrid cross?
the ratios will be different than the typical 9:3:3:1 ratio
indicates that the genes are linked
incomplete dominance
blending of phenotypes in heterozygotes
penetrance
% of individuals with a given genotype who display the associated phenotype
whether or not phenotype is there
example of penetrance
someone may have the gene for breast cancer, but not develop breast cancer
expressivity
severity of phenotype
to what degree is the phenotype present
segregation
allele pairs segregate randomly from each other into gametes
independent assortment
alleles for separate traits are independently inherited
genetic recombination
crossing over can unlink two genes on the same chromosome
genetic linkage
two genes close together on the same chromosome are likely to be inherited together
1 centimorgan
distance associated with a 1% change in recombination frequency
double crossover
can reverse recombination on genes far away from each other on the same chromosome
When does a cell commit to mitosis?
after the G1 phase
by starting to replicate DNA, the cell has committed to mitosis unless derailed at later checkpoints
fitness
likelihood to survive in a given environment and REPRODUCE
inclusive fitness
traits passed on that promote survival of the group
ex: altruism and empathy
What does the Hardy Weinburg equation connect?
alleles to phenotypic frequency in a population
What do terms mean in Hardy Weinburg?
2pq = heterozygous q^2 = homozygous recessive p^2 = homozygous dominant
p= dominant allele frequency q = recessive allele frequency
stabilizing selection
favors intermediate phenotypes
directional selection
favors one extreme phenotype
disruptive selection
favors extreme phenotypes over the intermediate
inverse of stabilizing selection
genetic drift
change in gene pool due to chance
more likely in smaller populations
examples of genetic drift
bottleneck effect and founder effect
bottleneck effect
natural disaster leaves small population with certain traits expressed at unnaturally higher levels
founder effect
population migrates away and has less genetic variation
gene flow
movement of alleles due to migration between populations
types of reproductive isolation
prezygotic and postzygotic barriers
convergent evolution
species not from same common ancestor develop the same trait
parallel evolution
species from same common ancestor develop same traits independently
divergent evolution
species from common ancestor evolve different traits
coevolution
two or more species evolve in response to each other
is symbiosis always beneficial?
no
symbiosis can harm one of the species or have no effect
mutualism
type of symbiosis where both species benefit
commensalism
type of symbiosis where one species benefits and the other feels no effect
parasitic
type of symbiosis where one species benefits and the other is harmed
archaea
unicellular prokaryotes
thrive in extreme temp, pH or salt conditions
use unusual energy sources
MRSA
multidrug resistant strain of bacteria
bacillus
rod shaped bacteria
spirilli
spiral shaped bacteria
coccus
sphere shaped bacteria
aerobes
bacteria that require oxygen
obligate anaerobes
bacteria that cannot survive in the prescence of O2
aerotolerant anaerobes
tolerate oxygen and can survive
facultative anaerobes
can metabolize O2 if present or not
plasmids
smaller circular DNA fragments that can be transferred between bacteria
What is the bacterial cell wall made up of?
peptidoglycan
gram positive bacteria
have a thick peptidoglycan cell wall that allows the gram dye to stick to
gram negative bacteria
have a lipopolysaccharide outer membrane that is washed off with ethanol during gram staining
makes the bacteria gram negative
is it harder to break down gram positive or gram negative bacteria?
gram negative due to their outer membrane
svedberg units
describe how long it takes a particle to sediment in a test tube due to centrifugation
how can antibotics attack ribosomes?
they can specifically attack the smaller sized ribosomes of bacteria
binary fission
how bacteria reproduce
single cell divides into two identical daughter cells
4 phases of bacterial growth
1) lag phase - bacteria adapt to a new environment, little growth
2) exponential phase
3) stationary phase when population has reached max
4) death phase due to scarce resources for large population
transformation
bacteria’s ability to absorb genetic material from their environment
is horizontal gene transfer bacterial reproduction?
no! the cell only reproduces during binary fission
transduction
a bacteriophage (virus) injects bacterial DNA into other bacterias
conjugation
special plasmid (fertility factor) is transferred between two bacterial cells using a sex pillus
what is viruses goal?
to hijack cellular machinery in order to multiply and spread
virion
fully assembled, infectious virus
has capsid
enveloped viruses
have a protein, capsid
must be transferred by bodily fluids
example of an enveloped virus
HIV
ssRNA + virus
can directly start translation on a ribosome
very quick working virus
What are the two options for an RNA virus?
must either be immediately translated (ssRNA +)
or must be reverse transcribed back into DNA (retrovirus)
retrovirus
a virus that uses reverse transcriptase to put RNA back into the host’s genome
capsid
a protein coat that encloses viruses
composed of repeating monomers, form pretty spontaneously
viroid
affect plants
bacteriophage replication
either virus goes into lytic cycle inside the bacteria host and produces tons of bacteriophages, rupturing the cell
or the virus goes into the lysogenic cycle and inserts itself into the bacteria’s genome and can later initiate the lytic cycle
prions
misfloded proteins that lead to aggregated proteins
protozoa
single cell parasites
helminths
multicellular worm parasites
ectoparasites
exist outside the body like ticks and lice
what component of the innate immune system works on parasites?
eosinophils
how can recombinant DNA be used?
mass produce proteins (like insulin)
make alterations to genes
recombinant DNA
DNA that has been formed artifically by combining consitutents from different organisms
What are the steps for using recombinant DNA?
1) synthesize a gene sequence or “insert” with proper restriction sites
2) Digest the insert with a restriction enzyme
3) Ligate the vector with the plasmid through DNA ligase
4) Insert the plasmid into the bacteria to replicate
5) Select and isolate bacteria of interest
What is one method to see if recombinant DNA is present in bacteria?
include a gene for antibiotic resistance on the DNA vector and insert into bacteria
treat bacteria with antibiotic and see if resistant
how do restriction enzymes contribute to recombinant DNA?
restriction enzymes cut DNA with sticky ends so the DNA can be inserted into the plasmid
definition of gene expression
all the ways in which cells can regulate transcription and translation of genes
How can you classify stem cells?
along a scale of potency
totipotent cells
stem cells that are able to differentiate into any type of cell
applies only to the zygote
pluripotent cells
stem cells that can differentiate into any of the germ layers (ectoderm, mesoderm, endoderm)
can be obtained from the blastocyst
blastocyst
structure formed in the early development of mammals
multipotent
adult stem cells that can differentiate into a limited scope of different cell types
operons
regulate gene expression in prokaryotes
allow bacterium to respond to changes in their environment
negative control of operons
a repressor can turn off transcription
positive control of operons
an activator can turn on transcription
similarity of the lac operon and trp operon
both involve negative control
difference of the lac operon and trp operon
lac operon is inducible negative control
trp operon is repressible negative control
How does the lac operon work?
the lac operon is normally turned off unless there is lactose present and limited glucose
the repressor is usually present on the lac operon
allolactose
binds with lac operon repressor and removes the repressor to stimulate production of lactose digesting enzymes
cAMP and the lac operon
when glucose levels are low, cAMP levels are high
cAMP binds to CAP (an activator for the lac operon) to activate it
How does the trp operon work?
the trp operon is normally turned on to synthesize tryptophan unless there are high levels of tryptophan
tryptophan will bind to the trp operon to stop synthesizing tryptophan
promoters
upstream regions of DNA that initiate transcription
help recruit RNA polymerase to initiate transcription
examples of eukaryotic promoters
TATA box and GC/CAAT box
transcription factors
proteins that regulate expression by binding to a specific DNA sequence
enhancers
allow gene expression at even higher levels
how do enhancers work?
form a hairpin loop to bring distant regions of the DNA together
difference between enhancers and promoters
enhancers can be located far away from the gene of interest
silencers
the opposite of enhancers in DNA transcription
turns transcription off
DNA methylation
generally thought to deactivate genes
also contributes to epigenetics
How does non-coding RNA play a role in transcription?
siRNA and miRNA degrade mRNA sequences before translation
eRNA (enhancer RNA) can increase transcription
tumor initiation
the first step of oncogenesis
allows cell to bypass usual checkpoints of the cell cycle
tumor progression
cell develops the ability to proliferate even more aggressively
angiogenesis
tumor forms a new blood vessel to feed the growing tumor
tumor promoters
help induce the growth of proliferative cells by stimulating the activity of proteins involved in growth and division
How do tumor viruses work?
they contain retroviral oncogenes which are reverse-transcribed into the DNA of infected cells
often encode proteins that are key components of signaling pathways that stimulate cell proliferation
proto-oncogenes
genes that function as oncogenes after mutation or inappropriately elevated levels of expression
tumor supressor genes
inhibit oncogenesis when properly functioning
TP53 gene
tumor supressor gene that encodes the p53 protein involved in responding appropriately to cell damage
BRCA genes
tumor supressor genes that repair and respond to DNA damage
misfunctioning BRCA genes can often to lead to cancer
What template do retrovirus use for reverse transcriptase?
ssRNA
Can antibodies be specific for intracellular material of a pathogen?
No, antibodies respond to extracellular antigens
What are capsids made of?
proteins
How is reverse transcriptase introduced to host cell?
transfered from the inside the capsid
reverse transcriptase is fully formed inn the capsid
Magnesium and DNA
magnesium has a stabilizing effect on DNA
Magnesium and ATP
magnesium has a stabilizing effect on ATP
positive charge stabilizes the negative repulsion?
Why does aggregation not occur during the cooling phase of PCR?
cooling phase is carried out at a temperature way above the physiological temp
What bonds contribute most to DNA stabilization?
hydrophobic effect that pushes the nucleotides towards each other, away from the aqueous environment
not the hydrogen bonds between nucleotides
where does B-oxidation of fatty acids occur?
in the mitochondria of eukaryotic cells
in the cytoplasm of prokaryotic cells
sexual dimorphism
genetically determined physical differences between the sexes
retrograde transport
moves protein backwards
ex: would move from the Golgi to the ER
cytochrome c
is composed of a heme group with one Fe
therefore, can only transport one electron at a time
In what direction does RNA polymerase read DNA and synthesize hnRNA?
read in 3’ to 5’
synthesizes in 5’ to 3’ continously
antisense strand
the template strand that RNA polymerase uses
sense strand
also known as the coding strand
DNA
is identical to the newly synthesized hnRNA strand
complementary to the antisense strand
What strand does RNA polymerase read?
RNA polymerase reads the antisense strand
What is the precursor to mRNA?
hnRNA
3’ polyA tail
post-transcriptional modification
facilitates nuclear export
protects mRNA against degradation from exonucleases
5’ Cap
post-transcriptional modification
protects mRNA against degradation
site for rRNA recognition in translation
difference between splicing and cleavage
splicing is a post-transcriptional modification to mRNA while proteolytic cleavage cuts proteins to change their function
spliceosome
catalyzes RNA splicing to remove introns
snRNPs
ribosomal catalysts found in spliceosomes
recognize binding sites on introns to cut
makes loop to splice out
What does RNA splicing allow for?
diversity in proteins
Is translation spontaneous?
no, requires energy
In what direction does elongation happen?
mRNA strand is read 5’ to 3’
new protein is synthesized from N to C-terminus
What happens during initiation of translation?
rRNA binds to 5’ cap and tRNA corresponds to AUG codon and binds Met / large subunit
Where are carbohydrates added to the protein?
in the golgi
ubiquitine
can be added to protein to trigger degradation
proteolytic cleavage
can cut inactive protein zymogen to activate it when needed
What is the path an egg takes prior to fertilization?
ovary to abdominal cavity to fallopian tubes
How does the sperm enter the egg?
must pass through the corona radiata and bind to specific zona pellucida
acrosome reaction
the sperm binds with zona pellucida and releases hydrolytic enzymes into egg
cortical reaction
egg releases cortical granules so no other sperm enter egg
how does the zygote travel after fertilization?
moves through fallopian tubes into uterus while dividing into morula
blastocyst
fluid filled cavity
buries itself in the uterine wall
regions of blastocyst
trophoblast (outer layer) will develop into placenta
inner cell mass will develop into fetus
gastrulation
formation of 3 germ layers
endoderm
urinary, digestion and respiratory tracts
mesoderm
muscles, connective tissue, bone
circulatory system, kidneys, adrenal gland
gonads
ectoderm
nervous system and external structures
neuralation
early formation of neural system
notochord and neural plate form
neural plate
bends to form groves and the neural tube which becomes the CNS
neural crest cells
move away from the neural plate to form the PNS
hCG
hormone secreted by mothers during pregnancy, along with progesterone, that pregnancy tests detect
SRY gene
on Y chromosome
codes for testes and prevents female features from forming
umbilical artery
moves deoxygenated blood away from the fetal heart
mutagen
a DNA damager
chemical mutagens
reactive oxygen species
silent mutation
a substitution mutation with no change
spontaneous mutation
a mutation in DNA without exposure to a mutagen
nonsense mutation
a substitution mutation that changes an amino acid codon to a stop codon
missense mutation
substitution mutation that switches a single codon
conservative missense mutation
codon is replaced by a codon that codes for a very similar amino acid
ex: threonine to serine
nonconservative missense mutation
codon is replaced by a codon that codes for a very different amino acid
ex: threonine to proline
How can we get frameshift mutations?
through insertion or deletion
Loss of function mutations
prevent proteins from working properly
mismatch repair
occurs during DNA replication
if exonucleases miss a mutation, mismatch repair can find the incorrect nucleotide and replace it
base excision repair
removes a single erroneous base
occurs throughout the cell cycle
nucleotide excision repair
removes multiple erroneous bases
occurs throughout the cell cycle
what type of repair mechanism would repair UV damage?
nucleotide excision repair
translocation
a sequence of genes switches places from one chromosome to another
inversion
mistake takes place in the directionality of a chromosome
does not lead to serious problems
aneuploidy
having too few or too many copies of a given chromosome
intracrine signals
stay within the cell they are secreted by
autocrine signals
move out of and then reattach to the same cell they were secreted by
juxtacrine signals
signals move between adjacent cells
paracrine signals
signals can travel between nearby cells
types of membrane receptors
1) Ion-channel linked
2) Enzyme linked
3) G-protein-coupled
Ion-channel linked receptors
pores let ions in when a ligand binds to the receptor
Example of an enzyme linked receptor
receptor tyrosine kinases
How do receptor tyrosine kinases work?
tyrosine “tails” dimerize and activate a phosphorylation cascade of theirselves and target proteins
G-protein
a heterotrimeric protein that binds to GTP/GDP
Steps of G-protein coupled response
1) ligand binds externally to GPCR and triggers conformational change
2) G-protein is activated
3) alpha subunit dislocates and activates adenylyl cyclase
4) adenylyl cyclase makes cAMP
5) cAMP activated PKA, which can phosphorylate targets
6) At same time, beta and gamma subunits activate IP3 which releases Ca2+ and activates kinase C
Two types of G-proteins
Gs - stimulatory
Gi - inhibitory
hybridization
binding through complementary nucleotides
autoclave
a biological lab technique that increases pressure and temperature in order to kill bacteria
SDS-PAGE
SDS is applied prior to gel electrophoresis to give all the molecules a negative charge
then, when the molecules migrate through the gel, they will separate based on size
Where are negative and positive charges in gel electrophoresis?
anode: molecules migrate towards positively charged anode
cathode: molecules migrate away from negatively charged cathode
Steps of blotting
First use gel electrophoresis to separate molecules based on size
Then, transfer contents of gel to nitrocellulose membrane
Detect molecules of interest with antibodies (proteins) or with hybridization (nucleic acids)
B-mercaptoethanol
a reducing agent that can linerize DNA by reducing disulfide bonds
What are each of the blotting techniques used to study?
SNoW DRoP
Southern - DNA
Northern - RNA
Western - Protein
What are DNA microarrays used for?
can analyze lots of genes simultaneously on same chip
often used to analyze two entire cell line samples
How do DNA microarrays work?
flourescently label mRNA that matches with cDNA on chip
Sanger Sequencing / Chain Termination method of DNA sequencing
stop replication early and add ddNTP to label nucleotide
each ddNTP is labeled with a different color
use gel electrophoresis to separate different terminated strands based on size
read flourescent ddNTPS in order of increasing length to build genetic sequence
How many primers are needed for PCR?
two primers
a forward and a reverse primer
Steps of PCR
first denature DNA
then anneal primers
then allow for elongation
What type of DNA polymerase does PCR use?
Taq polymerase since it is good at high temps
Why does DNA not aggregate during cooling phases of PCR?
cooling phases are still carried out very much above the physiological temperature
3 types of exocrine glands
1) apocrine - releases products by membrane budding
2) merocrine - directly secrete through exocytosis
3) holocrine - cells rupture to release products
Signal sequence
sequence that allow transmembrane proteins to enter the endomembrane system
Nicotinamide
the name for NADH
Chondrocytes
make collagen
What is cartilage made of?
collagen
Ligaments
connect bone to bone
Tendons
connect muscle to bone
Epiphyseal plate
where cartilage is produced for bones to grow
also known as the growth plate
Joints
where bones meet
Synovial joints
are free to move
Fibrous joints
hold two bones together with fibrous connective tissue
Hydroxyapatite
crystallized minerals in the bone matrix
storage for -OH, calcium, and phosphate
Osteoblasts
build new bones
Osteroclasts
break down bones
What hormone(s) stimulates the activity of osteoclasts?
parathyroid hormone and calcitriol
What hormone(s) stimulates the activity of osteoblasts?
calcitonin from thyroid gland
Calcitriol
comes from vitamin D
increases amount of calcium in serum
Osteon
ring structure of bone matrix that blood and nerves pass through
live in lacuna
Yellow bone marrow
stores adipose cells
