3 lecture 4 Flashcards
what is an embryo
a fertilized egg is a one cell embryo
how many types of cells can an embryo generate
this cell has the capacity to generate >200 types of cells in the human body
what are the potential to forms that an embryo may develop into
totipotent (fertilized egg)
pluripotent (embryonic cell)
unipotent (adult cell)
what is totipotent (fertilized egg)
able to differentiate into any cell type
what is pluripotent (embryonic cell)
can form many types of cells within the same lineage
means that you can make similar types of cells
e.g. your skin is actually composed of many types of cells, but they all have a common cell they divide from
the ultimate stem cell is the first cell of an embryo
what is unipotent (adult cell)
can divide to produce more skin cells
not stem cells…
what is The flow of genetic information
DNA → RNA → protein
in how many steps does the information flow happen
occurs in 2 steps: Transcription
Translation
what is Transcription
(DNA → RNA)
what is Translation
(RNA → Protein)
what is meant by “you are the sum of your parts, more or less”
each cell in your body (except sperm and egg cells) has the same DNA
but each cell only expresses a small percentage of all its genes
example: nerve and muscle cells perform very different functions, thus they use different genes.
turning a gene (or a set of genes) on or off = regulating gene expression
why do repressors bind to the promoter
prevent the RNA polymerase from binding
this is essentially “hitting the OFF switch” (to stop/refrain traits from coming)
what do activators do
activators help the RNA polymerase bind to the promoter
this is basically “hitting the ON switch” (to “get” the traits needed)
DNA, RNA and protein can be measured but to evaluate expression, what is often used
RNA
measuring mRNA is the best way to measure the expressed proteins
you can dye the mRNA and track it
what is A heat map
is a graphical representation of data where the individual values contained in a matrix are represented as colors (e.g. green/red)
what do heat maps do
heat maps aid in comparison of very complex data (many genes/mRNAs, many conditions)
in general, a heat map displays relative abundance
colours are arbitrary, e.g. red can be high or low, colours can be yellow/blue
black can mean the value is near/at the mean for all conditions
different genes are turned on or off as a cell gains what
“identity”
If it is anything other than a one-cell embryo, what type of cell is it
the answer is NOT totipotent (if this was asked on a test)
how does cell potential relate to cell identity
potential decreases as identity increases
what is the potential and identity of totipotent
high potential, low identity
able to express genes needed for any cell type
what is the potential and identity of pluripotent
low potential, high identity
can form similar types of cells
what is the potential and identity of unipotent
can divide to produce more of the same type of cells
pluripotent cell has 2 fates, what are they
renewal (as a pluripotent) and committed (when it has an identity)
what does ICM stand for
Inner Cell Mass
what is ICM
ICM forms all the cells of you trophoblast forms the placenta
what are the 4 types of cells
endoderm
mesoderm
ectoderm
germ cells
what is endoderm
liver cells
pancreatic cells
alveolar cells
what is mesoderm
cardiac muscle
skeletal muscle
smooth muscle
red blood cells
what is ectoderm
skin cells
nervous system
what is germ cells
egg
sperm
what are adult stem cells
tissue specific
hematopoietic stem cells (blood cells)
epithelial and epidermal stem cells (skin)
what is the purpose of regenerative research/stem cell research
identify drug targets and test potential therapeutics
study differentiation
understanding prevention and treatment of birth defects
