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2.1: Cell Structure 

Eukaryotic: membrane bound nucleus

Plant cells: cell wall, plastids, larger vacuole

Cytoskeleton: used for cell shape, internal structure, movement and cell division

Many cell are surrounded and supported by a complex extracellular matrix, able to interact with adjacent cells and environment via cell junctions.

Prokaryotes: no nuclear membrane, no mitochondria

Subunits of ribosomes are assembled from proteins and DNA in the nucleus

Name

Structure reference/ Analogy

Membrane?

Function

Nucleus

Pearl in an oyster.

Y

Contains & protects almost all the DNA - separated from cytosol or metabolic processes that may damage it. Makes ribosome units.

Endoplasmic Reticulum (ER)

Extension to nuclear envelope. Repeated, flat folds.

Y

Creates new polypeptide chains and sometimes enhances them into lipids or enzymes.

Golgi body

Stack of pancakes.

Y

Vesicles fuse and empty here. Put finishing touches on chains like phosphates and sugars to make membrane proteins and then shipped of to plasma membrane or lysosomes.

Transport/ Secretory vesicle

Marble-like structures.

Y

Transport within the cell or releases them from the cell.

Mitochondrion

Looks like a kidney bean or a small, wrapped baby.

Y

Own DNA. Makes ATP. Basically an aerobic bacteria that got comfortable.

Chloroplast

Two outer membranes with stroma inside. Stroma may look like stacks of coins.

Y

Contains enzymes, pigments and traces of DNA. Plastid.

Lysosomes

Recycling centers: hold digestive enzymes.

Y

Vesicle containing powerful digestive enzymes. Carry disposals.

Peroxisome

Recycling centers: Hold catlase

Y

Vesicle containing enzymes for digesting fatty or amino acids.

Vacuole

Garbage bins.

Y

Vesicle that stores waste and aids in cellular metabolism and water balance. Maintains pressure.

Ribosome

Folded ribbon.

N

Assemble polypeptide chains.

Centriole

Two pills or logs lying on top of each other.

N

Makes tubules for cell division.

  • Nuclear Membrane: Double membrane of 2 lipid bi-layers. Contains proteins that are receptors, transporters & spanners. Restricts access to DNA.

  • Nucleoplasm: vicious fluid similar to cytosol

  • Nucleolus: Dense, irregularly shaped region. Sub-units of ribosomes are assembled from proteins and RNA.

  • Chromatin: DNA & associated proteins in nucleus.


  • Endomembrane system: system of interacting organelles. Make lipids, enzymes & proteins for secretion/insertion into cell membrane. Destroys toxins. Recycles waste.

    • Nucleus: DNA → RNA → Nuclear pores → Cytosol

    • Rough ER: Cytosol => Polypeptide chains (by ribosomes)

    • Vesicles: bud from ER carrying chains to Golgi bodies, some go through interior of Rough ER

    • Smooth ER: The latter are packaged into Vesicles and sent off, some become enzymes. Rich in protein oriented cells.

    • Golgi body: Modified and sorted. New vesicles take them to plasma membrane or lysosomes.


  • Plastids: membrane-bound organelle that is involved in photosynthesis and storage in plants and algae

    • Chloroplast: double membrane, enzymes and pigments for photosynthesis - in stroma

    • Chromoplasts: stores pigments other than chlorophyll

    • Amyloplasts: stores starch


Visual Reference

AV

2.1: Cell Structure 

Eukaryotic: membrane bound nucleus

Plant cells: cell wall, plastids, larger vacuole

Cytoskeleton: used for cell shape, internal structure, movement and cell division

Many cell are surrounded and supported by a complex extracellular matrix, able to interact with adjacent cells and environment via cell junctions.

Prokaryotes: no nuclear membrane, no mitochondria

Subunits of ribosomes are assembled from proteins and DNA in the nucleus

Name

Structure reference/ Analogy

Membrane?

Function

Nucleus

Pearl in an oyster.

Y

Contains & protects almost all the DNA - separated from cytosol or metabolic processes that may damage it. Makes ribosome units.

Endoplasmic Reticulum (ER)

Extension to nuclear envelope. Repeated, flat folds.

Y

Creates new polypeptide chains and sometimes enhances them into lipids or enzymes.

Golgi body

Stack of pancakes.

Y

Vesicles fuse and empty here. Put finishing touches on chains like phosphates and sugars to make membrane proteins and then shipped of to plasma membrane or lysosomes.

Transport/ Secretory vesicle

Marble-like structures.

Y

Transport within the cell or releases them from the cell.

Mitochondrion

Looks like a kidney bean or a small, wrapped baby.

Y

Own DNA. Makes ATP. Basically an aerobic bacteria that got comfortable.

Chloroplast

Two outer membranes with stroma inside. Stroma may look like stacks of coins.

Y

Contains enzymes, pigments and traces of DNA. Plastid.

Lysosomes

Recycling centers: hold digestive enzymes.

Y

Vesicle containing powerful digestive enzymes. Carry disposals.

Peroxisome

Recycling centers: Hold catlase

Y

Vesicle containing enzymes for digesting fatty or amino acids.

Vacuole

Garbage bins.

Y

Vesicle that stores waste and aids in cellular metabolism and water balance. Maintains pressure.

Ribosome

Folded ribbon.

N

Assemble polypeptide chains.

Centriole

Two pills or logs lying on top of each other.

N

Makes tubules for cell division.

  • Nuclear Membrane: Double membrane of 2 lipid bi-layers. Contains proteins that are receptors, transporters & spanners. Restricts access to DNA.

  • Nucleoplasm: vicious fluid similar to cytosol

  • Nucleolus: Dense, irregularly shaped region. Sub-units of ribosomes are assembled from proteins and RNA.

  • Chromatin: DNA & associated proteins in nucleus.


  • Endomembrane system: system of interacting organelles. Make lipids, enzymes & proteins for secretion/insertion into cell membrane. Destroys toxins. Recycles waste.

    • Nucleus: DNA → RNA → Nuclear pores → Cytosol

    • Rough ER: Cytosol => Polypeptide chains (by ribosomes)

    • Vesicles: bud from ER carrying chains to Golgi bodies, some go through interior of Rough ER

    • Smooth ER: The latter are packaged into Vesicles and sent off, some become enzymes. Rich in protein oriented cells.

    • Golgi body: Modified and sorted. New vesicles take them to plasma membrane or lysosomes.


  • Plastids: membrane-bound organelle that is involved in photosynthesis and storage in plants and algae

    • Chloroplast: double membrane, enzymes and pigments for photosynthesis - in stroma

    • Chromoplasts: stores pigments other than chlorophyll

    • Amyloplasts: stores starch


Visual Reference

robot