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Chapter 4: Evolution of Cells & Their general Features - Coggle Diagram
Chapter 4: Evolution of Cells & Their general Features
The membranes that enclose the nucleus and part of a larger network of membranes.
Endomembrane System
Endoplasmic Reticulum
Smooth ER
Provides large surface area for enzymes, involved in carbohydrate metabolism, muscle contraction, and synthesis and modification of lipids. No ribosomes on surface.
Rough ER
Sorts proteins, inserts newly made proteins into ER membrane, and attaches carbohydrates to proteins & lipids (glycosylation). Has ribosomes on its surface.
Lysosomes
Digest substances that are taken up via endocytosis. Break down intracellular molecules and macromolecules to recycle their building blocks, autophagy.
Vacuoles
Central vacuoles in plants store H2O, enzymes and Ca ions. Provide support and pressure on the cell wall, turgor
pressure
Contractile vacuoles in protists for expelling excess water
Phagocytic vacuoles in protists and white blood cells for degradation
Peroxisomes
Catalyze certain reactions that break down molecules by removing hydrogen/adding oxygen. Catalase breaks down dangerousH2O2 into water and oxygen
Plasma membrane
The boundary between the cell and the
extracellular environment
Membrane transport in and out of cell, with
selective permeability
Cell adhesion
Cell signaling using receptors
Nuclear Envelope
Double membrane that encloses the nucleus, housing genetic material
Nuclear pores provide passageways of molecules and macromolecules
Organelles with DNA that can grow, divide and reproduce themselves, not completely autonomous as they depend on the cell for synthesis of internal components.
Semiautonomous Organelles
Mitochondria
Produces ATP and is involved in the synthesis, modification, and
breakdown of several types of cellular molecules
Divides by binary fission
Chloroplast
Carry out photosynthesis by capturing light energy and using some of that energy
to synthesize organic molecules e.g., glucose
Divide by binary fission
Found in plants and algae
Involved in maintaining cell shape and providing mechanical strength.
Cytoskeleton
Protein Filaments
Actin
Known as microfilaments, 7nm
Long, thin fibers and dynamic with + and - ends, growth occurs at + end via addition of actin monomers
Dispersed throughout cytosol, highly concentrated near plasma membrane
Microtubules
Long, hollow cylindrical structures, α and β tubulin subunits, 25nm
Dynamic instability, important for sorting of chromosomes in cell division
Can grow from + end and shorten in either the + or - end
Intermediate
Intermediate in size e.g. keratin, Lamin10 nm
Form twisted, ropelike structure
Length is permanent
Found in nucleus, hair, skin, kidney cells
Nucleus
Membrane bound compartment that contains and stores DNA
Nucleolus
Droplet organelle of nondividing cells that assembles ribosomes
Ribosomes
Site of polypeptide synthesis
Cytosol
Region of eukaryotic cell that is outside the organelles but inside the plasma membrane, where metabolism and synthesis occur
Cytoplasm
Region enclosed by the plasma membrane, includes cytosol and organelles