Please enable JavaScript.
Coggle requires JavaScript to display documents.
Cell and organelles: structure and function 20187137-Nguyen Le Hung -…
Cell and organelles: structure and function 20187137-Nguyen Le Hung
Method
Cell fractionation
Homogenization → centrifuge
Cell observing under microscope
Light microscopy
Brightfield / Darkfield
Phase-contrast
Fluorescence
Confocal
Electron Microscopy
TEM (Transmission Electron Microscope)
SEM (Scanning Electron Microscopy)
Cryo-EM (Cryo-electron microscopy)
Cell size and scale
THE SIZE RANGE
0.1 to 100 micrometers
surface area and volume
Total surface area = (height
width)
number of boxes
Total volume = [height
width
length *
number of boxes]
Surface-to-volume = [surface area ÷ volume]
Cell shape
Surface Area Example
Small Intestine:
Villi:
Microvilli:
Root hairs:
extensions of root epidermal cells; increase surface area for absorbing water and minerals
Cell types
Prokaryotic cell
plasmid
DNA
pili
cell wall
capsule
flagella
Eukaryotic cell
microfilament
lysosome
microtubule
endoplasmic reticulum
peroxisome
mitochondria
vacuole
golgi
intermediate filaments
nucleus
both cell
cytoplasm
ribosome
cell membrane
structure and function
cell
Extracellular components
Plasma membrane
Cytoplasm
Cytosol
Non membrane structures:
Cytoskeleton
Centrosomes
Ribosome
Proteasome
Single membrane organelles:
Endomembrane system
Endoplasmic reticulum
Golgi apparatus
Lysosome
Vacuole
Peroxisome (glyoxysome)
Double membrane organelles
Mitochondria
Chloroplasts
Nucleus
Main cell function
Provide structure and support
Control metabolism
Produce energy
Movement
Reproduction
Extracellular components
Most cells synthesize and secrete materials that are external to the plasma membrane
extracellular matrix
Composed of glycoproteins
Strengthens tissues and transmits external signals to cell
Cell walls
pectic, cellulose and protein
Plasmodesmata: channels between cells
Intercellular junctions
Tight junctions:
Desmosomes:
Gap junctions:
Plasma membrane:
a selective barrier that allows sufficient passage of oxygen, nutrients, and waste to service the volume of every cell
The general structure of a biological membrane is a double layer of phospholipids
Cytoplasm
Cytosol (Intracellular fluid)
protein
ions
water
macromolecules
No membrane structures
One membrane organelles
Endoplasmic reticulum, Golgi apparatus, lysosomes, vacuoles
One membrane organelles
Mitochondria, plastids
Centrosomes
microtubule organizing center
Animal cells contain centrioles
region from which microtubules grow
Cytoskeleton
network of protein fibers
Microtubules
Cell shape maintenance
Shape/support cell
Guiding movement of organelles
Forms spindle
Component of
cilia/flagella
Microfilaments
Cell shape maintenance
Support cell on smaller scale
Cell movement
Intermediate Filaments
Cell shape maintenance
Permanent fixtures
Anchorage of nucleus
Fix position of organelles
Formation of nuclear lamina
Proteasome
acts as the cell's "garbage disposal," crucial for maintaining proteostasis by degrading damaged, misfolded, or unnecessary proteins tagged with ubiquitin
Ribosomes
protein synthesis
Composed of rRNA + protein
Endoplasmic Reticulum
Rough
ribosomes on surface
package proteins for secretion, send transport vesicles to Golgi, make replacement membrane
Smooth
no ribosomes on surface
synthesize lipids, metabolize carbohydrates, detox drugs & poisons, store Ca2+
Golgi Apparatus
synthesis and packaging of materials (small molecules) for transport (in vesicles); produce lysosomes
Lysosome:
intracellular digestion, recycle cell’s materials, programmed cell death (apoptosis).
Contains hydrolytic enzymes
Vacuoles
storage of materials
Membrane-bound vesicles
Plants: large central vacuole
Peroxisomes
break down fatty acids; detox alcohol. Involves production of hydrogen peroxide
Mitochondria
site of cellular respiration
Cristae: folds of inner membrane; contains enzymes for ATP production; increased surface area to n ATP made
Chloroplasts
site of photosynthesis
Thylakoid disks in stacks (grana); stroma (fluid)
Contains chlorophylls (pigments) for capturing sunlight energy
Nucleus
control center of cell
Contains nucleolus and chromatin with DNA
Surrounded by double membrane (nuclear envelope)
Continuous with the rough ER