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Features and structures of cells - Coggle Diagram
Features and structures of cells
Cells are the smallest units of life
New cells come only from pre-existing cells by
cell division
Two categories of life
Prokaryotes
No nucleus
Simple cell structure
Two categories
Archaea
small cells, 1 μm – 10 μm in diameter
Bacteria
Small cells, 1 μm – 10 μm in diameter
Some species are pathogenic
Vast majority are not harmful to humans
Very abundant in environment and our bodies
Eukaryotes
DNA enclosed within membrane-bound nucleus
There are membrane-bound organelles
More complex cells
Compartmentalized functions
Each organelle has a unique structure and function
Shape, size, and organization of cells vary considerably
Parts in a Prokaryote
Ribosomes– synthesize proteins
Cell wall – provides support and protection
Nucleoid region – where DNA is located
Glycocalyx– traps water, gives protection, help evade
immune system
Cytoplasm– contained within plasma membrane
Appendages
pilli (for attachment)
flagella (for movement)
Parts in eukaryotes
Plant cells
Animal cells
Nucleus: Area where most of the genetic material is organized and expressed
Nuclear envelope: Double membrane that encloses the nucleus
Nuclear envelope: Double membrane that encloses the nucleus
Nuclear pore: Passageway for molecules into and out of the nucleus
Centrosome: Site where microtubules grow and centrioles are found
Endoplasmic Reticulium
Smooth ER: Site of detoxification and lipid synthesis
Rough ER: Site of protein sorting and secretion
Mitochondrion: Site of ATP synthesis
Cytosol: site of many metabolic functions
Cytoskeleton: Protein filaments that provide shape and aid in movement
Peroxisome: Site where hydrogen peroxide and other harmful molecules are broken down
Golgi apparatus: Site of modification, sorting, and secretion of lipids and proteins
Lysosome: Site where macromolecules are degraded.
Plasma membrane: Membrane that controls movement of substances into and out of the cell; site of cell signaling
Ribosome: Site of polypeptide synthesis.
Cell wall: Structure that provides cell
Central vacuole: Site that provides storage; regulation of cell volume.
Chloroplast: Site of photosynthesis
Cytoskeleton:
provides cell shape, Organization and Movement
Network of three types of protein filaments
Intermediate filaments
Intermediate in size
Form twisted, ropelike structure
Can be composed of different proteins including keratin, lamin, and others
Diameter: 10 nm
Common functions
provide cells
with mechanical strength
anchorage of cell and
nuclear membranes
Cell shape
Actin filaments
Also known as microfilaments
Long, thin fibers
Two intertwined strands composed of the protein actin
Common functions
cell strength
muscle
contraction
Cell shape
intracellular movement of cargo; cell movement (amoeboid movement)
cytokinesis in animal cells
Microtubules
Long, hollow cylindrical structures
Dynamic instability
Diameter: 25 nm
Common functions
Cell shape
organization of cell
organelles
chromosome sorting
in cell division
intracellular
movement of cargo
cell motility in cilia and flagella