cell bio Flashcards
what is cell biology
the study of cells at microscopic and molecular levels
describe phospholipid structure
- hydrophilic heads (love water, interact with water)
- hydrophobic tails (hate water, do not interact with water)
molecules that speed up a chemical reaction without changing
catalysts
what are the two types of prokaryotes
bacteria (eubacteria) and archaea (archaebacteria)
what element are biomolecules centred around
carbon
______ are not present in plant cells
cholesterol, type of lipid steroid
what are the two organelles that plants have that animals lack
chloroplasts and vacuoles
name the organelle:
contents of the whole cell that are within the plasma membrane but outside the nucleus
cytoplasm
portion of cytoplasm that is outside membrane enclosed organelles
cytosol
generation of ATP happens where
mitochondra/chloroplasts
most membrane protein and soluble organelle protein synthesis happens where
endoplasmic reticulum ER
sorting of proteins and lipids from ER happens where
Golgi apparatus
which organelle contains genome, DNA and RNA synthesis
nucleus
what organelle move most material between organelles and up-taken extracellular molecules
endosomes
organelle that degrades unneeded intracellular organelles and extracellular molecules that get brought into the cell
lysosomes
aggregate of molecules based on weak, multivalent interactions between scaffolds and client molecules which keep them in the area, lack surrounding membranes
biomolecular condensates
transport of proteins from one compartment to another by membrane-bound intermediates (vesicles)
vesicular transport
a membrane enclosed dynamic cellular organelle that is involved in the selective transport of proteins/material to other compartments
vesicle
process of a protein moving across a membrane
protein translocation
dense core of enzymes involved in many processes and also the site of synthesis and destruction of hydrogen peroxide
peroxisomes
where do peroxisome proteins come from
- peroxisomal membrane proteins come from the ER with peroxisome precursors
- proteins from cytosol
in the mitochondria there are how many membranes and how many aqueous spaces?
2 membranes: outer member and inner membrane
2 aqueous spaces: matrix and intermembrane space
where are proteins that are made in the ER translated?
on ribosomes attached to rough ER
where are proteins that are made in the cytosol translated
on free ribosomes in cytosol
what happens in the smooth ER
- synthesis of steroid hormones
- storage of calcium ions
- detoxification of alcohol and liver cells (barbiturates)
Term for the portion of each amino acid that gives the amino acid its unique properties
side chain
protein folding is mediated by what kind of interactions
non-covalent (ionic, van der waals, etc)
when folding of protein begins right away what is it called
co-translational
what helps proteins fold into shape
chaperons
what are the two folding patterns of secondary protein structure
- alpha helix
- beta pleated sheets
two alpha helices wrap around each other, made by interacting hydrophobic regions on proteins
coiled-coil
in beta pleated sheets where do the arrows point to start and end
start: N
end: C
protein secondary structure is characterized by what bond
H bonds
what are the two types of tertiary structured proteins
FG: fibrous and globular proteins
what tertiary protein is usually structural materials outside of cells ex. Keratin, collagen
fibrous proteins
what kind of protein is a prion protein
a plasma membrane protein
normal prions are folded with what
alpha helices
prion disease leads to neuronal death which does what to the brain?
makes the brain spongey which is fatal!
group of proteins that share origin (related function or similar sequence/structure)
Protein families
what must fit precisely into a binding site of a protein
a ligand
positive regulation of an allosteric enzyme by
an activator molecule
end product of metabolic pathway inhibits earlier enzymes that help make it.
feedback inhibition
enzymes that adds the phosphate
kinase
enzymes that removes the phosphate
phosphatase
reactions that occur in response to stimulus
signalling cascades
addition of methyl group, typically represses gene expression
methylation
addition of acetyl group, typically enhances gene expression
acetylation
small molecule bound to enzyme and participates in catalysis reaction
coenzyme
oxygen carrying protein that requires iron atom to function
heme
bind multiple proteins to improve the probability of their interaction and confine proteins to certain regions/compartments of the cell
scaffolds
separation of cell components by size and density mediated by high speed centrifugation.
cell fractionation
donor and acceptor fluorescent molecules allow us to visualise protein interactions
FRET
allows us to study protein movement
FRAP
forces that are several times that of gravity are applied on solutions to increase the rate and which different components settle in the tube based on size.
centrifugation
chromatography where separation is based on size
gel filtration chromatography
chromatography where separation is based on charge
ion exchange chromatography
chromatography where separation is based on ability to bind a protein
affinity chromatography
addition of sugars (carbohydrates) onto proteins
glycosylation
Two types of proteins are involved in targeting vesicles to specific compartments
Rab and SNAREs proteins
on which terminal of ER proteins is the retrieval signal located
C terminal
process by which the contents of secretory vesicles are released into the extracellular environment
exocytosis
eukaryotic cells that lack surrounding membranes but concentrate biomolecules proteins and nucleic acids
biomolecular condensates
random movement of particles
brownian motion
cells harness what for movement?
brownian motion (random movement of particles)
archaea is structurally similar to __________but genome is closer to ___________
bactera, eukaryotes
what do eukaryotes have but prokaryotes dont
organelles and nucleus
eukaryotes consist of what four groups of organisms
animals, plants, fungi and protists
combination of 2 cells living in symbiotic relationship - one cells lives inside the other
endosymbiont theory
simplified controlled environment
culture
homogenous cells that have undergone modifications to grow continuously in culture, once placed in culture, these cells keep growing and replicating
cell line
culture obtained directly from the organism
primary culture
extent to which the detail of a specimen is retained in the image
- dependent on the wavelength of light
resolution
produces higher resolution images by excluding out of focus light
confocal microscopy
can produce higher resolution images by overcoming diffraction limit
superresolution microscopy
a protein that exhibits green fluorescence when exposed to light
green fluorescent protein (GFP)
uses electrons as a light source, the image is formed when electrons pass through a specimen
electron microscopy
best used for viewing detailed structures within cells and tissues, specimens are stained with heavy metal solutions
TEM
best used for viewing extensions or processes that cells use to interact with the environment, specimens are dried, coated with C and metals and shot at with electrons
SEM
particular atom grouping that behave as a unit
functional groups
what reaction forms polymers by joining monomers
condensation, water is removed
what reaction breaks down polymers into monomers
hydrolysis, water is added
use an energetically favourable reaction to drive an energetically unfavourable reaction
reaction coupling
what type of bonds link fatty acids to glycerol
ester bonds
what are monosaccharides linked by
COC linkages
energy stored in easy to convert form
carrier molecules
an electrophoresis method that allows protein separation by mass.
SDS PAGE
enzymes that add sugars onto proteins are called
glycotransferases
addition of sugars (carbohydrates) onto proteins
glycosylation
glycosylated proteins/ sugary proteins are called what
glycoproteins
helps relieve the stress on the ER causes by defective proteins
UPR. unfolded protein response
an example of an ER protein folding disease is
cystic fibrosis
