Cell Structure Flashcards
what is the powers for the following units:
kilo, milli, micro, nano
kilo - 10^3
milli - 10^-3
micro - 10^-6
nano - 10^-9
how do you calculate magnification
image size / actual size
what is cell fractionation
the process of seperating cell organelles from eachother
what is ultracentrifugation
the cells in a sample being broken open via being spun at high speeds for a certain time to seperate the organelles.
what are the steps to seperate cells by there mass (5)
- crush the cells with a blender
- filter to remove cell debris (makes a cell homogenate)
- pour into a test tube and spin in a centrifuge
- pour supernatent and respin at a higher speed.
- repeat ro get lighter organelles
what is the solid / liquid called that forms from celll centrifugation
solid - pellete
liquid - supernatent
what are the 3 test conditions for cell centrifugation and why must they be maintained
- cold temp so enzymes don’t denature and stops enzyme activity due to a drop in KE
- control the pH to avoid protein damage
- control the water potential to prevent osmosis
what type of microscope cana observe living and non living specimens
light
which microscope produces a 3D image
Scanning electron microscope
how does a scanning electron microscope work
electrons are reflecterd from the surface on the specimen and then these are detected
how does a transmission electron microscope work
electrons pass through the specimen and then theyre detected
what are artefacts
dust or air bubbles
what stain must be used for plants and what for animals
plants - iodine solution
animals - methelyne blue
what is an eyepiece graticule
an eyepiece with a transparent ruler with numbers but no units
what is a stage micrometer
a microscope slide with an accurate scale with units which is placed in a microscope slide
how do you use the eyepiece graticule and stage micrometer
1 - callibrate the two by lining the 0 on the eyepiece graticule with one of the stage micrometer divisions
2 - see how many intervals on the eyepiece graticle is equal to one interval on the stage micrometer
3 - divide the value of one stage micrometer interval by the number of eyepiece graticule intervals its equal to
what are the 4 components of the nucleus
nucleur pore
membrane bilayer
DNA
nucleuolus
what are histone proteins
round proteins that DNA wraps around - makes it compact
what do nucleur pores do
allow controled exchanged between the nucleus and cytoplasm
what are the 5 components of the mitochondria
inner membrane
outer membrane
inter membranal space
matrix
cristae
where does aerobic respiration take place in the mitochondria
the matrix and on the cristae
what is the size of ribosomes in a eukaryotic / prokaryotic cell
eukaryotic - 80s
prokaryotic - 70s
what is the rough endoplasmic reticulum and what does it do
extended system of membrane sacs that is covered in ribosomes
transports and synthesises proteins
what is the smooth endoplasmic reticulum and what does it do
a system of membrane sacs, but no ribosomes
synthesis and transports lipids, steroid, hormones and carbohydrates (also stores carbs)
what is the golgi apparatus and what does it do
a stack of flattened membranes
modifies proteins
makes lysomes
collects and sorts molecules, that are then transported in golgi vesicles to other parts of the cell or theyre exocyted
what can golgi vesicles store
enzymes
what are lysosomes and what do they do
a vesicle which contains hydrolytic enzymes such as lysozymes
what makes up the cell wall in plants / fungi / algae
plants - cellulose
fungi - chitin
algae - cellulose or glycoproteins
how permeable are cell walls
fully
what are the 7 components of the chloroplast
stroma (internal fluid)
intergranal lamellae
granum
thylakoids
inner membrane
outer membrane
starch grains
what is a stack of thylakoid discs called
grana
what stores cell sap in the permanent vaculoe
tonoplast
name all the animal cell organelles (9)
nucleous
ribosomes
cell membrane
cytoplasm
mitochondria
golgi apparatus + vesicles
lysosomes
smooth endoplasmic reticulum
rough endoplasmic reticulum
name all the plant cell organelles (12)
nucleous
ribosomes
cell membrane
cytoplasm
mitochondria
cell wall
permanent vacuole
chloroplasts
golgi apparatus + vesicles
lysosomes
smooth endoplasmic reticulum
rough endoplasmic reticulum
what are the four main human tissues
epithelial
connective
muscular
nervous
what does epithelial tissue do
protect organs by lining there surface
what are the 5 main plant tissues
palisade mesophyll
spongey mesophyll
epidermis
xylem
phloem
what is the function of the xylem
transports water and mineral ions throughout the plant, whilst also offering mechanical support
what is the order of cell organisation
cells
tissues
organs
systems
organisms
what are the organelles found in a prokaryotic cell (7)
ALL HAVE
cytoplasm
70s ribosomes
circular loop of DNA
cell wall
SOME HAVE
plasmids
capsule
flagella
what is a prokaryates cell wall made of
murein - a glycoprotein
what is the role of the capsule in prokaryates
protects the cell and allows adhesion
are viruses a prokaryate
no theyre not cells (acellular)
what are the components of viruses (4)
DNA / RNA
proteins capsid
attatchment proteins
enzymes
what is the name for bacterial mitosis (asexual reproduction)
binary fission
what is the process of binary fission
circular DNA and plasmids undergo DNA replication
cell then divides into 2 new identical cells
how do viruses replicate (5)
1 - attatchment proteins on the virsus surface attach to a host cells complementary reseptors
2 - virus then enters the cell and uncoats to release its own DNA
3 - virus DNA is replicated by the host
4 - virus uses the hosts protein synthesising system
5 - releases new viruses to affect other cells
what are the 3 sections of interphase
G1 - cell increases in size and new organelles are made
S - DNA synthesis
G2 - further increase in size and new organelles made
what are the 4 phases of mitosis
prophase
metaphase
anaphase
telephase
what is it called when the cell splits
cytokinesis
what are the 6 parts of a chromosome
chromosome
chromatid
centromere
DNA
chromatin
histone
what is one strand of the chromosome called
chromatid, the two together are sister chromatids
what are chromatins
uncoiled DNA and histones
what holds the chromosome together
centromere
how many chromosomes do humans have
46
is coiled or uncoild DNA visable
coiled
what happens during prophase (3)
- supercoiling
- DNA wraps around histones
- Nucelur envelope dissapears
what happens during metaphase
all copied chromosomes align themselves around the equator (92), held there by the spindle apparatus
what happends during anaphase
chromsomes split and migrate to opposing poles, led by the centromere
what happens during telephase (3)
cell begins to spilt
nucleur envelope beings to reform
DNA starts to uncoil
what is cancer
uncontrollable cell division which is caused by a gene mutation
what controls the rate of cell division
genes
what are the 3 types of cancer treatment
chemotherapy
radiotherapy
immunotherapy
what do most cancer treatments aim to do
controlling the rate of cell division by disrupting the cell cycle
