Cell Structure and Functional study Flashcards
What does fluorescence microscopy show
the DNA and multiple proteins within the same cell
What are the different fluorescence microscopy colors based on organelle
alpha tubulin- green actin-red DNA- blue golgi complex- yellow mitochondria- purple
Plasma membrane
protects cells interior from environment
allows biochemical reaction to proceed in a controlled manner
Ribosomes
construct polypeptides from amino acids
Cytoskeleton
dense protein network that gives cell its structure and shape
cytoplasm
everything between plasma membrane and nucleus
consists of semi fluid matrix (cytosol)
organelles with double membrane
mitochondria, nucleus, and chloroplast
major membrane enclosed organelles
lysosomes, vacuole, endoplasmic reticulum, golgi, mitochondria, chloroplasts, nucleus
function of biomembranes
protection of cytoplasm from toxic substances, regulation of what goes in and out, and compartmentalize related enzymes
How does regulation of the biomembrane work
selectively permeable membrane
receptors on the plasma membrane detect hormones and send signal tp cytoplasm
Why is compartmentalizing related enzymes important
helps to have more concentrated substrate, biochemical reactions can proceed much faster
characteristics of lysosomes
very acidic to denature proteins and contains enzymes
What do lysosomes do
breakdown of macromolecules
Destroy larger, insoluble items brought into cell via phagocytosis
Autophagy (cell cleaning)
Lysosomes and disease
defects in macromolecule breakdown leaving an accumulation of them and thus leading to toxicity and cell death
ex. tay sachs disease
What do peroxisomes do
similar to lysosomes
detoxify cell- contain oxidases that neutralize free radicals
oxidize fatty acids- take large fatty acids and oxidize them into acetyl groups
What is ALD disease
defective peroxizomal fatty acid oxidation
Function of vacuoles
contain similar degradative enzymes (and acid) as lysosomes
universal storage facility for plant cells
regulates cell size
What is the endoplasmic reticulum
extensive network of membrane sacs that are all connected to one another
sacs are called cisternae
empty space called ER lumen
what differentiates rough and smooth ER
Rough has ribosomes studded on it
Smooth ER function
synthesis of lipids
metabolism of carbs
detoxify drugs and poisons
store calcium ions in certain cell types
Rough ER function
protein synthesis
membrane synthesis
Name of golgi side close to ER
cis face
Other side of golgi not close to ER
Trans face
Function of glogi
makes carbs
receives proteins from rough ER and puts finishing touch
packages proteins into new vesicles and directs where they go
Mitochondria Function
breakdown organic compounds into CO2/ H2O and convert the released energy into ATP
Function of chloroplasts
photosynthesis (production of glucose)
Chloroplast structure
two membranes
third inner membrane that forms flattened interconnected sacs called thylakoids
Nucleus function
protects/ organizes genetic material
organizes the production of ribosomes
site where the genetic code is read and copied to RNA
Key features of the nucleus
Nuclear envelope: double layer membrane, contains nuclear pores
Nuclear lamina: complex meshwork of protein filaments that lines inner layer of envelope give shape and structural support
Chromosomes/ chromatin
Nucleolus- where RNA is made and ribosomal subunits made
Properties that differ between cell types of organelles
size/shape
density
unique proteins/lipids
What is the issue with size and density with eukaryotic cells
most have similar densities and sizes
methods to differentiate cells based on presence of unique proteins
Fluorescence activated cell sorter (FACS)
Laser capture microscopy
Process of FACS
label cell of interest with fluorescent dye
put mixture into machine that moves cells through laser beam
laser detects cells. with/ without fluorescence
cells separated based on how much light they emit
What is a plus to FACS
cells are alive so can study function
How to fluorescently label a specific cell type
chose protein found on surface of cell type and add fluorescently labeled antibody that binds to selected protein
Laser capture microscopy method
prep thin section of tissue
use microscope to find cell or group of cells that want to isolate
laser will melt small plastic probe that is then touched to the cell fo interest
after cooling the probe is lifted up taking cell with in
Methods of plasma membrane mechanical disruption
- stir cells in high speed blender
- sonication (shooting sound wave through cell)
- Dounce homogenization- cell sheared by forcing through narrow space
- Repeated freeze/thaw cycles- disrupt cells through ice Crystal formation
- osmotic pressure
What does differential centrifugation separate structures by
size and shape
large move to bottom faster then smaller one
Order of spins of differential centrifugation
Nucleus first
second spin at higher speeds will pellet mitochondria, lysosomes, chloroplasts
Even higher speeds will pellet plasma membrane, golgi, ER, and vesicle membranes
everything left is ribosomes and small cytoplasmic molecules
Stepe to purifying organelles
- breaking cells open
- separating groups of organelles by differential centrifugation
- isolating specific organelles by equilibrium centrifugation
Equilibrium density gradient process
- create density gradient using sucrose or glycerol and put organelle mix on top
- Spin tube for fixed period of time (organelle will move to region of tube that has same density as itself)
Other way to isolate organelles
using specific antibody and attaching metal ion to it, organelle will move to it
