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Tour of the cell - Coggle Diagram
Tour of the cell
Eukaryotic cells genetic info
Nucleus-contains most of the cells genes, most conspicuous organelle
Nuclear envelope- encloses the nucleus, separates it from cytoplasm
nuclear lamina-lining of nuclear envelope and is composed of proteins & maintains shape of nucleus
Chromosomes- DNA organized by discrete units
chromatin- DNA molecule associated with proteins in chromosomes
nucleolus-sight of ribosomal RNA (rRna) synthesis
ribosomes-where proteins are made
Endomembrane system
golgi apparatus
FedEx of the cell (packages & delivers)
lysosomes-trash cans of the cells (digests macromolecules
phagocytosis- cell "eating" require ATP, lysosomes that come in contact with large foreign substances
pinocytosis- cell ''drinking'' require ATP, are lysosome that come in contact with small foreign substances
vacuoles-larger then vesicles
contractile vacuole-pumps excess water out of cells
central vacuoles- in plant cells contain sap
food vacuole
nuclear envelope
plasma membrane
Endoplasmic reticulum
accounts for more then half of total membrane in eukaryotic cells
Rough ER
distributes transport vesicles
membrane factory for the cell
bound ribosomes that secrete glycoproteins
Smooth ER
detoxes toxins
stores calcium ions
synthesizes lipids
Eukaryotic & Prokaryotic cells
prokaryotic
no membrane bound organelles
DNA unbound region called nucleoid
no nucleus
cytoplasm bound by plasma membrane
Eukaryotic
cytoplasm between nucleus & plasma membrane
larger than prokaryotic cells
membrane bound organelles
DNA in nucleus bound by double membrane
basic features of cells
semifluid sbstance(cytosol)
Chromosomes(carry genes)
plasma membrane=selective barrier
ribosomes(make proteins)
microscopes
used to visualize cells
scanning electron microscope(SEM)- 3D image of internal cellular structure
Transmission electron microscope(TEM)- looks for internal cellular structure
Light Microscope(LM)-light passes through specimen then glass lens
parameters of microscopy
magnification-ratio of object image size to real size
resolution-measure image clarity or minimum distance of two distinguishable points
contrast-differences in brightness between part of sample
cell fractionation-take cell apart & separates major organelles (centrifuge happens)
Mitochondria & Chloroplasts
mitochondria-sites of cellular respiration & ATP production
mitochondrial matrix created by inner membrane
peroxisomes: oxidation- specialized compartments bounded by a single membrane
cristae-smooth outer membrane and inner membrane folded
Chloroplasts-are the
sites of photosynthesis/ found in plants
stroma-internal fluid
part of plastids group of plant organelles
thylakoid-membrane sacs form a granum when stacked
Endosymbiont theory-suggest that an early ancestor of eukaryotes engulfed an oxygen using nonphotosynthetic prokaryotic cell
engulfed cell formed a relationship with the host cell, becoming endosymbiont
extracellular components
extracellular materials and structures are
involved in many essential cellular functions
plant cell walls multiple layers
primary cell wall-thin & flexible,secreted first
middle lamella-thin layer between primary walls,contains polysaccharide pectin
secondary cell wall(in some)-added between plasma membrane & primary cell wall
extracellular matrix-animals cells have these due to lack of cell wall (ECM)
made of glycoproteins
collagen
proteoglycans
fibronectin
ECM proteins bind to receptor proteins in plasma membrane called integrins
regulates cells behavior
ECM around cell can influence activity of genes in nucleus
cell wall-extracellular structure that helps distinguish plant cells from animals cells
helps protect plant cell
maintains it shape
prevents excessive uptake of water
made of cellulose fibers embedded into polysaccharides and protein
plasmodesmata-channels that connect plant cells
water & small solutes (some RNA & proteins) pass from cell to cell
3 types of cell junctions
demosomes(anchoring junctions)-fasten cells together into strong sheets
gap junctions- (communicating junctions) provide cytoplasmic channels between adjacent cells
tight junctions-membranes of neighboring cells press together preventing leakage of extracellular fluid
cell is greater than the sum of its parts
no cell component works alone
Examples
macrophages ability to destroy bacteria involves the whole cell
coordinating components such as the cytoskeleton, lysosomes, plasma membrane
Cytoskeleton
helps support the cell & help maintain its shape
motor proteins-produce cell motility
microfilaments
solid rod built as a twisted double chain of actin subunits
form a cortex inside plasma membrane to help support the cells shape
cellular motility contain protein myosin
psuedopodia-cells crawl along surface by extending cellular extension and moving toward them
cytoplasmic streaming-circular flow of cytoplasm in cells driven by actin protein interactions
microtubules
centrioles- pairs in centrosome that has 9 triplets of microtubules arranged in a ring
centrosome- microtubules in animal cell grow out of here near the nucleus
flagella
cilia
hollow tubes, help shape the cell, guide movement of organelles, separates chromosomes during cell division
cilia & flagella share common structure
dynein-motor protein that drives bending movements of cilia or flagella
basal body that anchors cilia or flagella
contain extensions that project from cells
intermediate filaments
range from 8-12 nanometers
support cell shape & fix organelles in place
more permanent feature then other two
larger than microfilaments but smaller than microtubules