2. Cell Flashcards
which are the 3 most important parameters in microscopy?
- Magnification
- Resolution
- Contrast
magnification
the ratio between an object image size/ its real size
resolution
the clarity of an image/ the minimum distance between two points
contrast
the difference in brightness between the light and dark areas of a microscope
LM (light/optical) horoscope is best used
for viewing cells/ bacteria
when dealing with living cells
phase-contrast microscope
used with living cells
uses light
uncolored parameters
EM-electron microscope is suited
for viewing viruses and molecules
but cannot view atoms
cell fractionation order:
dissociated cells
nuclei and cellular debris
mitochondria/chloroplasts/lysosomes
microsomes= pieces of cell’s internal membranes
ribosomes
which domains contain prokaryotic cells?
organisms of the domains
1. Bacteria
2. Archaea
what is glycocalyx?
the outer coating/ capsule of a bacterial cell
which organelles have 2 membranes
nuclei
mitochondrion
chloroplasts
one membrane-bound organelles:
ER
Golgi apparatus
lysosome
peroxysomes
vacuole
non-membrane-bound organelles:
ribosomes
centrioles
flagellum
cilia
cytoskeleton
which structures are acidophiles? (kane reaksion bazik?)
cytoplasm (ph>7)
mitochondrion
cytoskeleton
hemoglobin
collagen
where is circular DNA found?
plasmids
mitochondrion
chloroplast
extrachromosomal circular DNA found in the nucleus of eukaryotic cells
what do ribosomes contain?
rRNA and small portions of tRNA and mRNA
what is a peptide signal?
a code in the transcribed protein that decides the destination of the protein
Free ribosomes synthesize proteins for:
the nucleus
mitochondrion
chloroplasts
cytoskeleton
peroxisomes
enzymes that function in the cytosol
Bound ribosomes synthesize proteins for:
secretion
Golgi
ER
lysosomes
cell membrane
what does the endomembrane system include?
the nuclear envelope
ER
Golgi
lysosomes
vacuole
plasma membrane
where is cholesterol produced?
smooth ER
how is the detoxification carried out by smooth ER in liver cells?
by adding hydroxyl (OH) groups to drugs
which is the main zone of protein synthesis?
rough ER
Diktiosome
a second name for the Golgi apparatus
Golgi’s two sides are:
- the CIS face= on the same side as the ER and is a similar membrane to the ER’s
- the TRANS face= on the opposite side of the ER
where does the further modification of molecules happen in Golgi?
as they pass from the Cis face to the Trans face
which organelle is considered the second station of cellular transport?
Golgi
how are molecules transported from ER to Golgi
via vesicles as Golgi and ER are not directly linked
which side of Golgi secretes the productions of the organelle?
the Trans side and the secretions go and fuse with the plasma membrane or go to the cell wall
where are the secretory proteins produced?
ER
where are the membrane proteins produced?
ER
where are the lipids produced?
ER
where are the glycoproteins produced?
ER(first modification) and Golgi (last modification)
where are the glycolipids produced?
Golgi
where are hydrolytic enzymes(me natyre glukproteinike) and the lysosomal membrane produced?
Golgi apparatus
the pH inside lysosomes?
acid pH 5/ 5,5
why don’t the enzymes inside the lysosome hydrolise its membrane?
due to glycolised proteins:
LIMP
LAMP
LGP
Autophagy meaning?
lysosomes recycle the organic material of damaged organelles
TAY-SACH disease is the result of?
missing or inactive lipid-digesting enzyme
therefore the brain becomes weakened due to lipid accumulation in the cells
how does the large central vacuole in cell plants develop?
it develops from smaller vacuoles
what is CELL SAP?
the solution inside the central vacuole
which membrane of the mitochondrion is smooth and thick and more permeable?
the outer membrane
what is the function of the cell sap?
main storage of inorganic ions
K+
Cl-
cristae
infoldings of the inner complicated membrane of the mitochondrion
from which parent is the mitochondrion circular DNA inherited?
only from the mother
which phospholipids are found in the inner membrane of the mitochondrion
Kardiolipine
Termogenine
what is required for the formation of chlorophyll?
light
magnesium salt
iron ions
amyloplast
colorless organelle that stores starch
what do the enzymes of peroxisomes do?
remove hydrogen from molecules
bind H to oxygen
forms H2O2
converts H2O2 to H2O
where are GLYOXYSOMES found and what do they do?
found in the lipid-storing tissue of plant seeds
-converts fatty acids to sugar
the components of the cytoskeleton are:
- microtubules- tubulin
- microfilaments actin
- intermediate filaments keratine + other proteins
which is the thickest component of the cytoskeleton
microtubules
the main function of microtubules is:
chromosome movement during cell division
the thinnest component of the cytoskeleton
microfilaments
dimer structure?
1 dimer= 1 alpha tubuline + 1 beta tubuline
the function of intermediate filaments?
formation of the nuclear lamina
(the structure between chromatin and inner nuclei membrane)
centrioles structure
9x3 microtubules
only in animal cells
cilia structure
9x2 microtubules
movement back-and-forth/ flip flop
flagellum structure
9x2 microtubules
fish movement like swimming
basal body structure
9x0
is found in the flagellum of the sperm, enters the egg, and becomes a centriole
Dyneins
large motor proteins that allow the movement of flagellum/cilia
ECM
the extracellular matrix
the main components of ECM are:
glycoproteins (the most abundant is collagen)
other carbohydrates
The function of ECM is :
it communicates with the cells through INTEGRINS (proteins) so as to regulate cell behavior
Amphipathic molecules
a molecule with both hydrophilic and hydrophobic regions
Amphipathic molecules examples:
membrane lipids
membrane proteins
How is the membrane held together?
the membrane is mainly held together by Hydrophobic interactions which are weaker than covalent bonds
how do phospholipids move?
they move sideways in a rapid way
rarely a lipid may move from one layer to the other
How do plants resist the winter since they have no cholesterol?
they increase the percentage of unsaturated phospholipids
what do channel proteins (integrals) transport?
- huge portions of water (aquaporins)
- ions soluble in water
what do carrier proteins transport?
they transport glucose
they are specific (for example: the ones that transport glucose do not transport fructose even though they are similar isomers)
is there net movement in isotonic solutions?
no there is no net movement
water enters and leaves the cell at the same rate
CD4 and CCR5
proteins in immune cells that help HIV infect them leading to AIDS. firstly HIV must bind to CD4.
To infect the cell it must connect to CCR5 too. If CCR5 is missing the virus can’t enter the cell.
-CD4 and CCR5 are protein receptors
electrogenic pump
a transport protein that generates voltage across the membrane
example: sodium-potassium pump
what is the difference between endocytosis and exocytosis?
the protein involved
what form of transport does cholesterol use to enter cells?
through Receptor-mediated endocytosis (a specific type of pinocytosis)
is pinocytosis specific?
no
