cell biology Flashcards
What is a eukaryotic cell
a cell with a nucleus and membrane bound organelle
What is a prokaryotic cell
A cell without a nucleus which is smaller than a eukaryotic cell
Feature of a eukaryotic cell
Cytoplasm (Chemical reactions take place)
Ribosome (protein synthesis to turn DNA into protein on ribosome to make proteins and enzymes)
Mitochondria (site of respiration)
Nucleus (control centre)
cell membrane (controls what goes in and out of the cell)
Plant:
Cell wall ( gives structure)
Chloroplasts (photosynthesis)
Vacuole (keeps shape and storage of sap)
Features of a prokaryotic cell
Plasmids
Ribosome
cell membrane
cytoplasm
Where is DNA stored is different typed of cell
Eukaryotic cell
-Nucleus
Prokaryotic cells:
-Plasmids
-Nucleoid (single loop of DNA)
convertions
1000nm= 1μm
1000μm= 1mm
10mm= cm
1000mm= 1m
1000m= 1km
Pluripotent stem cells
can give rise to cells from all three different embryonic germ layers but once it goes down one path it can’t revert
three embryonic germ layers
Ectoderm- give rise to Neurons and sensory cells
Mesoderm- give rise to the cardiovascular system and blood cells
Endoderm- Liver, lungs, bladders and germ cells(egg and sperm)
Undifferentiated
not yet specialized
magnification vs resolution
magnification= how big it is
Resolution= how clear it is
Mitosis
-An X shaped chromosome is ready to divide
-A cell becomes larger and doubles the number of organelle
-During this time DNA is checked
-All of the chromosomes line up in the middle of the nucleus
-The nucleus disappears and spindles go from each chromosomes to opposite ends of the cell pulling the chromosomes apart
-when all of the chromosomes have been split the nucleus closes and two daughter cells have been formed
Embryonic stem cells
stem cells that are totipotent and can differentiate into anything
What is a stem cell
a cell that can be grown into more cells
what is diffusion
the movement of particals from an area of high to low density
factors affecting diffusion
concentration gradient
Blood supply
large surface area
small diffusion distance
moist surface
Osmosis
The movement of particals to and area of lower concentration through a partially permeable membrane
Surface area to body ratio
outside surface area : volume (volume should be 1)
binary fission
the asexual reproduction of bacteria:
the cell will grow and replicate genetic material
the DNA strands move to opposite ends of the cell
Plasmids arranged randomly so one offspring cell may get more
new cell wall starts growing in the middle
once the cell wall has grown the two cells pull apart
Bone marrow stem cells
can only turn into blood cells (red, white and platelets)
conditions that can be treated by bone marrow stem cells
severe aplastic anaemia (bone marrow failure)
leukaemia – a type of cancer affecting white blood cells
lymphoma – another type of cancer affecting white blood cells
multiple myeloma – cancer affecting cells called plasma cells
certain blood, immune system and metabolic disorders – including sickle cell anaemia, thalassaemia, severe combined immunodeficiency (SCID) and Hurler syndrome
Organisational hierachy
many cells make a tissue, many tissues make a organ many organs make an organ system and many organ systems make a organism
required practical 1 equipment
light microscope
slide
microscope
onion
tweezers
iodine
white tile
pre made animal cell slides
required practical 1 method
- peal off the top layer of the onion and place on the slide
- add a couple drops of iodine to stain the cells (goggles to prevent iodine to the eyes)
- gently place cover slip over the cells and avoid forming air bubbles - remove any excess stain
- place the slide on the stage of the microscope
- whilst looking through the ocular lense adjust the microscope going from the lowest to the highest resolution until the cells come into focus (be wary of the lenses though as to not allow the slide to come into contact with them
- draw what can be see and annotate diagram - remember to note down the magnification
- repeat steps 4-6 with the already prepared slides
