test 1
living things criteria
movement, repsiration, sensitivity, growth, reproduction, excretion, Nutrition, DNA (MRSGREND)
membrane bound organelles
eukaryotic
no membrane bound organelles
prokaryotic
unorganised and smaller
prokaryotic
no nucleus (free floating nucleolus)
prokaryotic
phospholipid bilayer is where
plasma membrane
what plasma membrane do
controls movement of molecules in/out of cell
cytosol/cytoplasm
intracellular fluid with dissolved materials (ions/water/proteins/molecules)
diff between cytoplasm and cytosol
cytoplasm is not in prokaryotic but cytosol in both
what ribosomes do
protein production (made or rRNA)
what golgi apparatus do
processes/packs proteins/lipids
what cell wall do
provides support/structure/protection
what chloroplast do
site of photosynthesis
what mitochondria do
site of aerobic cellular respiration (production of ATP)
endosymbiotic theory
chloroplast/mitochondria originates as microbes engulfed by another organism and gradually formed mitochondria/chloroplast
what nucleus do
maintains integrity of DNA, controls cell activity
what DNA do
contains genetic information for cell growth/division/function
DNA shape
helix w/ phosphate sugar backbone w/ nitrogenous base
what DNA contain
instructions (genes) needed to make cellular respiration (RNA/proteins)
types of cell movement
passive (no specialised structure needed and no energy required) and active (specialised structures and requires energy
what does greater volume mean
greater metabolism required(importing nutrients/exporting waste)
what surface area do
determines exchange of materials from cell/environment
larger cells means (SA:V)
smaller SA:V ratio and this less efficient
how to increase SA:V
larger surface area (in terms of photosynthesis)
more photosynthesis
plasma membrane do
active boundary where substances transpoted between internl/external enviro
do plasma membrane allow all
plasma membrane is semi permeable (selective)
types of proteins in phosphlipid bilayer
integral proteins (embedded in, carbs can attach (glycoproteins)) and peripheral proteins (anchored to exterior, done by bondibg w/lipids)
6 roles of proteins
TRACIE, transport, reception, anchorage, cell identity (glycolipids on cell allow for cell recognision), intracellular joining (joins cells together for communication) and enzyme activity(acts as catalyst)
phospholipid bilayer made of what?
hydrophilic head (ohosphate group) and hydrophobic tails (fatty acid chain) with proteins, carbs and cholesterol
role of cholesterol
regulates temp of phospholipid bilayer
osmosis
diffusion for water (high to low concentration)
what is down the concentration gradient
high to low concentration
simple diffusion, facilitated diffusion, osmosis
high to low, no energy
active transport, bult transport
low to high (up), movement kf larger particles
opposite of simple diffusion
facilitated (both no energy and down but one needs channel/carrier proteins other doesnt)
types of osmosis
isotonic (in/out), hypERtonic (water concentrated in (going out)) snd hypOtonic (concentrated out (going in))
where proteins pumps
actuve transport (enzyme function aids transport
types of bulk transport (eat/drink)
phagocytosis (eating), pinocytosis (drinking)
cell replication what is
asexual parent essentially cloning (no combination of DNA, exchange of gametes snd one parent) creates two identical daughter cells
why cell replication
growth, repair, procreation
binary fission what is
simple mitosis in prokaryotic cells where shit replicated
steps to binary fission
replication (dna chromosome, cell gets bigger), migration (two chromosomes formed, each migrate to opposite ends of cell) and the split (pinches into two with septum, stretches away in middle and creates two cells)
cell cycle in eukaryote steps
interphase (dna replicates), mitosis, cytokenisis
interphase steps
gap 1 stage (growth of cytosol, proteins are synthesised, mitochondria and chloroplast divide) then synthesis (DNA synthesises/replicated) parent cell contains two identical copies of DNA) and then gap 2 stage (doubles in size, proteins sunthesised form microtubules of spindle)
checkpoints
G1 (dna damage before replication), G2 checkpoint (checks for DNA replications errors after S stage) and M checkpoint (checks during metaphase of all chromosomes)
signalling molecules types
proto oncogenes (initate cell cycle, signal production of proteins, turns off to stop excessive cell production, mutstions cause cancer) and tumour suppressing genes (make proteins to signal cell stop dividing, can also repair DNA,, mutations lead to cancer)
when is there a balance between creating and dying cells
adulthood
rate if renewal=
rate of death
what is apoptosis
cell death
why is apoptosis
end of cells life, damges/diseased cells or excessive cells
mechanisms of apoptosis (intrinsic signalling)
in cell, due to damage/infection, assesses itsslf
p53 interacts w/ mitochondria
creates and informs apoptosome
enzymes (proteins) tell each other until apoptosis occurs (caspase cascade)
mechanisms of apoptosis (extrinsic signalling
immune system sends signal to the cell which the carbohydrate chain picks up
FADD receieves this
enzymes (proteins) send signal to eachother until apoptosis occurs (caspase cascade)
mechanisms of apoptosis (both)
devient cell behaviour is what
sometimes rate of renewal/production>rate of death
overproduction of cells cause what
cancer cells
overabundance of old/diseased cells cause what
alzeihmers, multiple sclorisis (bad stuff)
cancer cells form how
uncontrolled cell cucles (breakdown from regular)
cencer cells do what
mass produces cells (tumours) (malignant cells break off and migrate)
characteristics of cancer cells
no contact inhibition (crowded/multiple unorganised layers), unlimited, still divide after damaged (which creates abnormal cells/errors in DNA)
what are the sites of cell cycle for animals
there are many different sites
sites of cell cycles in plants
in roots and shoots
what is cell differentiation
when cells become specialised to perform specific functions
what are stem cells
cells that have not undergone differentiation (specialisation)
can differentiated cells become other cells and perform mitosis
nope
what prevents differentiation
protein oct4
why wouldnt you want stem cells to differentiate
so that they can renew/divide over long periods of time
how are different types of stem cells distinguishable
by their potency (how many diff types of cells they can become)
types of stem cells (in potency order)
totipotent
pluripotent
multipotent
oligopotent
unipotent
what is totipotent
the most powerful stem cell
can produce all cell types!
can generate fully functional living organisms
which stem cells are embyronic
toti and pluri
what is pluripotent stem cells
the second most powerful
can become many diff types of cells
can be made in labs
how are pluripotent cells made in labs
by harvesting less potent stem cells and treating them
what is the most powerful stem cell in med fields
pluripotent as toti is too controversial
which stem cells are somatic
multipotent
oligopotent
unipotent
what is multipotent sten cells
can self renew and differentiate into specific range of cell types (families)
what is oligopotent stem cells
similar to multipotent but further resiricted (closely related cell types only)
what is unipotent stem cells
least potent
can only become the same type of cell
what is an embryonic stem cell
a cell derived from inner mass cells of an earky embryo at blastoctyst stage (early in fertilisation)
can be obtained via IFV
why do embryonic stem cells rais ethical concerns
it destroys the embryo to take the cells
what is a parthenote
an unfertilised egg
can be artificially stimulated to begin development but not capable of becoming human
what is a somatic cell
adult stemm cells
can be obtained crom various sources in the body (such as bone marrow)
what is IPS
induced pluripotent stem cells
specialised adult somatic cells
can be genetically reprogrammed
created by addition of four genes that encode proteins that keep stem cells undifferentiated
what occurs within basal stem cells of epidermis (skin)
within the cell division, one stem cell is produced to become the parent cell and one cell is produced to differentiate
also skin cells at the surface fill with keratin and die
what are haematopoietic stem cells
located in bone marrow (somatic)
divide to give rise to different cells of the blood family
what are regenerative stem cells
stem cells used fo repair tissues/fix organs anomalies etc
steps to theraputic cloning
-patient needs help
-disease free cells taken from patient
-enucleation (removal of nucleus) of egg
-fusion of egg and cell (IVF)
-zap with hella electricity
-embryo cultured (artificially made) and stem cells removed
-put in disc, treated/programmed for cell types
what is theraputic cloning
the creation of an embryo through somatic nucleur transfer to obtain stem cells that treat patient
this provides a genetic match
benefits of therapitic cloning
complete genetic match
this means there is not immune respone
also less ethical issues than embryonic stem cells
what is gap stage 1
gap 1 stage (growth of cytosol, proteins are synthesised, mitochondria and chloroplast divide)
what is the synthesis stage of interphase
synthesis (DNA synthesises/replicated) parent cell contains two identical copies of DNA)
what is gap stage 2
gap 2 stage (doubles in size, proteins sunthesised form microtubules of spindle)
what is endosymbiosis concept
the theory regarding how eukaryotic cells have membrane bound organelles
what is endosymbiosis in terms of action
a prokaryotic cell absorbed a prokaryotic cell and the cell inside was able to maintain life, creating a cell inside of a cell, meaning it could uave membrane bound organelles as the cell could not be labelled as much more complex, creating a eukaryotic cell
what is the supporting evidence of endosymbiosis
the mitochondria and chloroplast having their own DNA and membrane
what is another term for the model of the phosphplipod bilayer
fluid mosaic model
when is bulk transport used
with big cells
what is active transport
transport using pumps