Midterm 1 Flashcards
Vacuole?
Large vesicles derived from the ER and GA, membrane is semi-permeable
Storage of nutritious molecules, poisonous molecules, lytic enzymes, pigments, water
prions vs Viroids
Prions: misfolded version of normal cellular protein, convert correctly folded proteins into prions (degenerative disease)
Viroids: infectious RNA molecules that replicate using plant host cell
Tight junctions?
plasma membranes of adjacent cells are bound together by proteins
Prevents leakage of fluid through the epithelium layers impermeability
epithelial cells such as skin cells and enterocytes or endothelial cells such as blood vessel cells
Gap junctions?
similar to plasmodesmata in plant cell
6 proteins (connexins) form a channel and allow the communication of adjacent cells.
letting through ions and small molecules
Nucleus?
contains the genetic material in the form of Chromosomes
Surrounded by nuclear envelope/supported by nuclear lamina
Pore complexes regulate the entry and exit of nucleic acids and proteins
what 2 organelles have a double membrane?
Mitochondria and chloroplasts
Actual central dogma?
RNA to protein, can go RNA to RNA or RNA to DNA, or DNA to DNA or DNA to RNA
Cellular respiration equation?
C6H12O6 + 6O2 —– 6CO2 + 6H2O + ENERGY
Thykaloids?
membranous flat sacs inside chloroplast that are stacked, contain photosynthetic pigments (chlorophylls)
loat inside the stroma
Peroxisome?
organelle that contains enzymes that remove hydrogen atoms from substrates and transfer them to oxygen
Breaks down fatty acids
Detoxifies
Plant cell wall?
contains cellulose, create secondary cell wall for support and separation
Lysosomes?
Digestive organelle that contains hydrolytic enzymes (digestion of macromolecules)
fusion of lysosomes with phagocytosis vesicles allow the digestion of preys or pathogens into simple sugars or amino acids
Reproduction of prokaryotes vs eukaryotes?
Prokaryotes: asexual through binary fission into two identical daughter cells, 1 RNA polymerase
Eurkaryotes: sexual reproduction requiring meiosis and fertilization have diploid 2n and haploid n phases, 3 RNA polymerase
Animal cell wall?
extracellular matrix, network made of glycoproteins, polysaccharides and proteoglycan
Collagen fibers are embedded
Integrins can transmit information between the ECM and the cytoskeleton
Golgi apparatus?
Trafficking center: manufactures, receives, sorts, modifies, ships many molecules.
Vesicles arrive from the ER
Posttranslational modifications (PTMs). 88% of PTMs are either phosphorylation , glycosylation or acetylation
Plammosdenta?
plants, neighbouring cells are connected by cytoplasmic channels that go through the cell walls, making the membrane continuous
Centriole?
cylindrical structure in the centrosome of an animal cell composed of 9 microtubule triplets (“9+0 arrangement”)
example of plasmosdenta?
Ex: Shortroot (Shr) protein: transcription factor responsible for the outwards cell division in the root.
Fluorescent DNA probe shows that Shr messenger RNA is only found in central stele cells
Fluorescently labelled proteins indicate that the Shr protein is present inboth stele cells (Ste) and endothelial cells (End in B) and is located in the nucleus
Shr proteins pass through plasmodesmata and reach the neighbouring cell layers
Mich way does tubulin move?
Movements are caused by motor proteins powered by ATP
Kinesin move cargo towards the plus end
Dynein moves cargo towards the minus end
Functions of the cytoskeleton?
network of microtubules, microfilaments, and intermediate filaments within the cytoplasm.
mechanical, structural, transport, motility and signalling functions.
It is responsible for the maintenance and modifications of the cell’s shape
Mitochondria?
Double membrane-bound organelle that converts chemical energy acquired from the environment into chemical energy (ATP)
What are microfilaments?
actin filaments: thin filaments composed of actin proteins acting alone or with myosin to cause cell contraction.
Double chain of actin subunits
Resist compression and maintains the shape of the cell
What are only in eukaryotes?
Complex chromosomes
Complex membranous cytoplasmic organelles
Cytoplasmic organelles for aerobic respiration and photosynthesis
Proteins and filaments
Phagocytosis
4 kinds of microscope? (LTSF)
Light Microscope
Transmission Electron Microscope
Scanning Electron Microscope
Flurorescence Microscope
Prokaryates?
Absence of nucleus.
Presence of a nucleoid
Absence of organelles
The cytoplasm is therefore made of the cytosol
Flagellum
What is archea?
prokaryotes that aren’t bacteria, extremophiles, many are methanogens (use CO2 and H2 to produce methane)
Rough vs Smooth ER
Rough ER: ribosome-studded, synthesis of proteins that are secreted by the cell, translated into ER lumen
Membrane proteins inserted into ER membrane before sent to other areas of the cell
Smooth ER: ribosome-free and contains many enzymes
Synthesis of lipids, phospholipids, steroids, cholesterol, carbohydrate metabolism
Calcium storage in the sarcoplasmic reticulum of muscle cells
What is the chloroplast?
organelle that converts solar energy acquired
from sunlight into chemical energy, converted by mitochondrion into energy (ATP)
Photosynthesis euqation?
ENERGY + 6H2O +6CO2 —- C6H12O6 + 6O2
What is a tubulin?
a dimer : ɑ-tubulin and β-tubulin.
has an orientation “plus end” and “minus end”
can grow and shrink in length from the “plus end” through polymerisation
minus end is attached to the centrosome
Intermediate filaments?
strong and flexible filaments of intermediate size that provide mechanical support of the cell against physical stress,
only found in the cells of some animals, including vertebrates
more permanent
Can bear tension , maintain the shape of a cell and the nucleus and fix the position of organelles
What is a microtubule?
thick hollow rod composed of tubulin proteins.
What is the central dogma?
The sequential information is transferred from nucleic acid to nucelic acid or from nucleic acid to protein… but the transfer from protein to protein or protein to nucelic acid isnt possible
centrosome?
structure present in the cytoplasm of animal cells that functions as a microtubule-organizing center
Nucleous?
consisting of chromosomal regions
containing ribosomal RNA genes and proteins, site of of rRNA synthesis and ribosomal subunit assembly with the rRNA
Ribosomes then use mRNA to synthesize proteins
Electron gradient?
diffusion gredient of an iron, affected by both the concentration difference of ion across membrane and ion’s tendency to move relative to the membrane potential
Cilla/flagella?
have a core (axoneme) made of nine outer doublet microtubules and two inner single microtubules (“9+2” arrangement)
The sliding of microtubules onto each other depends on a motor protein (dynein)
Desmosones?
anchors adjacent cells together through transmembrane proteins that are linked to the intermediate filaments.
keep adjacent cells tight together, especially in tissues that can stretch
Muscle celles (myocyte)
Serial Endosymbiosis?
The mitochondrion originates from the phagocytosis of an aerobic bacterium by an archaea cell
The chloroplast originates from the phagocytosis of a photosynthetic bacterium by eukaryote.
Eukaryotes?
The cytoplasm includes the cytosol, organelles (except the nucleus), and some inclusions
Presence of a nucleus with linear chromosomes, made of chromatin
Projects from cytoskeleton
