Atom Molecule Organelle Cell Tissue Organ Organ System Organism Division of Cells Eukaryotic Cells Literally means True nucleus Have a nucleus Complex Cells Have membranebound organelles ID: 755975
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Slide1
CellsSlide2
Levels of cellular organization
Atom
Molecule
OrganelleCellTissueOrganOrgan SystemOrganismSlide3Slide4
Division of Cells
Eukaryotic Cells
Literally means “True nucleus”
Have a nucleusComplex CellsHave membrane-bound organelles
Organisms made of eukaryotic cells are called “eukaryotes”
Examples: Animals, Plants, Fungi, Unicellular organisms like paramecium and amoebaSlide5
Cellular Components
Cytoplasm
Gel-like substance within the cell where organelles are found
Cytoskeleton“Cell skeleton”
Network of protein fibers that maintain the shape of cell
Composed of three networks of fibers
Microtubules: largest; hollow tubes made of protein; determine cell shape; scaffolding
Intermediate Filaments: Provide strength of cell
Actin Filaments: smallest; contractile string-like proteins that allow for cell movementSlide6Slide7
Cellular Components
Cell Membrane
Semi-permeable barrier that encloses the cell
Regulates what enters and exits the cell
Provides protection
Found in all types of cells
Cell Wall
Porous, rigid barrier found surrounding the cell membrane
Adds additional layer of support and protection
Not found in animal cellsSlide8
Organelles
Nucleus
Houses the genetic material (DNA) needed for replication of the cell
“Control Center” of the cellContains the instructions for the creation of proteins (made from DNA)
Exterior:
Surrounded by
nuclear envelope:
double-layered membrane that encloses the DNA; contains
nuclear pores:
small openings that allow for the passage of molecules between the cytoplasm and the nucleus
Interior:
DNA in the form of
chromatin
(string-like)
Nucleolus:
where ribosomes are made; very dense regionSlide9
Organelles
Endoplasmic Reticulum
A grouping of sac-like structures
Two Types of ER:Rough ER: contain ribosomes (creating ‘rough’ appearance); involved in the process of protein synthesis
Smooth ER: no ribosomes; involved in lipid synthesis
Ribosomes
Location where proteins are made (protein synthesis)Slide10
Organelles
Golgi Apparatus
Looks like a stack of membranes (pancake-like appearance)
Modifies, sorts and packages proteins received from the ER.Break off from the golgi apparatus; floats freely in the cell or travels to cell membrane where it will eventually exit the cell.
Creation of lysosomesSlide11
Organelles
Lysosomes
Contain enzymes necessary for digestion of cell food or waste
Can break down lipids, carbs, proteinsDigest non-functional organelles, ‘cleaning up’ the cellSlide12Slide13
Organelles
Vacuoles
Sac-like structure responsible for storage of various materials (e.g. water, carbs, proteins, etc.)Slide14
Organelles
Mitochondria
The “Powerhouse” of the cell
Convert food energy into energy that is used by the cell itself (for growth, development, movement, etc.) via cellular respiration
ATP (Adenosine Triphosphate)
Complex structureSlide15
Organelles
Chloroplast
Site of photosynthesis
Energy from sun is captured and converted into chemical energyContain the pigment chlorophyll which absorbs solar energy used in photosynthesis
Responsible for the green color of plantsSlide16
Organelles
Centrioles
Made of microtubules
Located near nucleusOrganize microtubules within the cytoskeleton prior to cell division Slide17
Division of Cells
Prokaryotic Cells
Include Bacteria &
ArchaeaLiterally means “before nucleus”
So-have no nucleus
Lack membrane-bound organelles
Simpler and much smaller than Eukaryotes
Organisms made of prokaryotic cells are called “prokaryotes”Slide18
Structure of Prokaryotes
Three basic shapes
Bacilli: rod-shaped bacteria
Cocci: Spherical-shaped bacteria
Spirilla
: Spiral-shaped bacteria; flexibleSlide19
Prokaryotic Cell Parts: Interior
Do prokaryotic cells have DNA if they lack a nucleus?
Nucleoid: a region within the cytoplasm of the cell in which the DNA is located; center of the cell (no membrane encloses the DNA)
Cytoplasm
Semifluid, gel-like solution encased within the cell membrane of the cellSlide20
Interior
Ribosomes
Made of two subunits (each containing a combination of various proteins and
rRNA) which work together to synthesize proteinLocated throughout the cytoplasmSlide21
External Layers
Cell Membrane
Regulates the entrance and exit of various substances in and out of the cytoplasm
Cell WallProvides shape, structure, and support for cell
Glycocalyx
The outermost layer of bacterial cells; gel-like protective layerSlide22
External Structures
Flagella
Allows for cell movement
Long, rotating filament that propels the cell forward
Fimbriae
Hair-like bristles located on the external surface of the cell
Allow cells to attach to surfaces
Conjugation
Pili
Tube-like structures that allow for bacteria to pass DNA from cell to
cell; usually larger and less numerous than fimbriae