2. Organelles

endomembrane system

1. Internal organelles that are connected with the jobs of interacting in the synthesis, distribution, storage and export of molecules

2. Nuclear envelope, golgi apparatus, lysosomes, vacuoles, plasma membrane

Cell Membrane/ Plasma Membrane

Biomolecules:

• lipid bilayer made up of two layers of phospholipids (move laterally) w/ cholesterol (lipid) that adds structure + lil carbs hang

• proteins: throughout membrane

  • Transport: moving molecules through membrane

    • cross: water?

    • enter: food, molecules (glucose), gasses (o2, Co2)

    • exit: proteins, wastes, gasses (o2, Co2)

  • Signal transduction: insulin

  • and more (for later)

• all cells

Function:

• to regulate the transport of materials entering + exiting cell, protection, fixed environment

• selective permeability: some substances pass through easier than others

• Fluid Mosaic Model: hydrophilic regions of proteins that interact w/ water as outer region + hydrophobic regions of proteins in nonaqueous environments as inner region

Cell Wall

Biomolecules:

• ?

• all except animal (just plant)

Function:

• rigid outer barrier surrounding cell membrane

Cytoplasm

Biomolecules:

• gelatinous liquid comprised of water, salts and other organic compounds that fills the cell

• all cells

Function:

• Transports, protects, maintains cell shape and structure, stores macromolecules + acts as host of metabolic processes. Also maintains optimal environment for cellular organelles

Cytoskeleton

Biomolecules:

• protein filaments + tubules = microscopic network in cytoplasm

• all cells

Function:

• maintains shape of cells + provides organization (ex: motor proteins)

• centrosomes: used as transport when cell is dividing

Centrioles/Centrosome

Biomolecules:

• proteins = parried barrel-shaped organelles located in the cytoplasm of animal cells near the nuclear envelope

• centriole + centriole = centrosome

• only eukaryotic + animal cells

Function:

• help to determine the location of the nucleus and organelles in the cell + organize cells for division + support/skeletal system

Flagella + Cilia

Biomolecules:

• made of proteins called microtubules = long wavy structure that extends from plasma membrane

• both euk + prok, only animal cells

Function:

• used to move entire cell

• cilia: moves molecules and lipids past cell membrane (often in animal) only euk

• flagella: facilitates movement in certain single cell organisms (sometimes in animal) (on the outside of cell) prok + euk

Nucleus + Nucleolus

Biomolecules:

• Nucleus: nucleic acids (DNA + RNA) + phospholipids (membrane-bound structure) that includes the nucleolus

• Nucleolus: nucleic acids (DNA + RNA) spherical structure inside cells nucleus

• only euk, plant + animal cells

Function:

• Nucleus: store genetic info

• Nucleolus: manufactures ribosomes (begins protein composition)

Ribosome

Biomolecules:

• nucleic acids (RNA), protein, little spheres on rough ER or in cytoplasm

• all cells

Function

• 2nd step of protein synthesis (linking amino acids into polypeptides)

Endoplasmic Reticulum (rough + smooth)

Biomolecules:

• Rough endoplasmic reticulum: proteins = layer type structure around nucleus + ribosomes

• Smooth endoplasmic reticulum: proteins = layer type structure around rough ER

• only eukaryotic, plant + animal cells

Function:

• Rough ER: protein folding (3rd step)

• Smooth ER: help produce lipids

Golgi Apparatus

Biomolecules:

• proteins = series of smooth, stacked membranes

• only eukaryotic, plant and animal cells

Function:

• transport, sort and modify proteins + lipids if needed (step 5) (a carbohydrate tail, adding a phosphate group, etc)

• package then transport into vesicles

Vesicles

Biomolecules:

• phospholipid shell + cytoplasm like liquid = membrane sacs

• only eukaryotic, plant + animal cells

Function:

• transport substances into and out of cell, often proteins (steps 4 & 6)

Lysosome

Biomolecules:

• phospholipid bilayer = membrane, small container within cytoplasm

• transport protein = let molecules thru

• eukaryotic, animal (rarely plant) cells

Function:

• use enzymes to break down general waste (used materials in cytoplasm) (hydroylsis)

Peroxisome

Biomolecules:

• phospholipids = single membrane-bound vesicles

• proteins = structure

• only eukaryotic, (rarley plant) + animal cells

Function:

• uses enzymes to break down fatty acids + amino acids

• neutralize harmful toxins so they don’t damage cells

  • ex: contain catalase for neutralization of hydrogen peroxide

Capsule

Biomolecules:

• proteins + carbohydrates = along cell wall

• only prokaryotic

Function:

• layer on the outside of cell wall that protects cell + stores nutrients

Chloroplast

Biomolecules:

• organized by internal membranes into diff compartments

• one compartment holds thick fluid called stroma (contains chloroplast DNA, ribosomes, and enzymes)

• only eukaryotic, plant cells

Function:

• conduct photosynthesis: Carbon Dioxide +H2O →(add sunlight) Glucose + Oxygen

Mitochondria

Biomolecules:

• double membrane structure, tiny

• proteins = ribosomes

• only eukaryotic, plant + animal cells

Function:

• make energy by breaking down food (glucose) using oxygen → stored as ATP

• powerhouse of the cell

Central Vacuole

Biomolecules:

• lipids + proteins

• only eukaryotic, plant + animal cells

Function:

• stores water, nutrients, and waste

• plant cells: large and in center

• animal cells: multiple smaller and only temporary space for waste + chemical reactions

Nucleoid

Biomolecules:

• nucleic acids = irregularly shaped region

• only prokaryotic cells

Function:

• stores all or most of the genetic material for cell

microtubules

straight, hollow tubes, assist cell shape and movement

microfilaments

solid rods, assist cell shape and movement