AP Bio: Cell Organelles

Organelles

• do the work of the cell
• each has a specific job to help keep the cell alive
• Make Energy
• Make Proteins
• And Reproduce

Funtion:

• manufactures membranes and performs bio-synthesis functions

Structure:

• membrane connected to nuclear envelope and extends throughtout cell
• accounts for 50% membranes in eukaryotic cell

Unofficial scaled size of a cell (for fun)

Human

Cell

Cell Organelles

By James Olsen and Judi Barcavage

Common Organelles

Types of Cells

- Determines what organelles they have

Cell Membrane

Endoplasmic Reticulum

Nucleolus

Function:

• seperates living cell from nonliving surroundings
• controls traffic in and out of the cell

Nucleus

Smooth ER:

• no ribosomes
• factory processing operations

Rough ER:

• bound ribosomes
• produce proteins for export out of cell

Cytoskeleton

• metabolic processes

Function:

• contains the cells DNA
• controls the growth and reproduction of the cell

Eukaryotes

• synthesis and hydrolysis

• Most complex cellular structures
• Contain a nucleus and membraneous organelles
• Are either Plant or Animal Cells

• enzymes of smooth ER

• protein secreting cells
• packaged into transport vesicles for export

Function:

• breeding location for ribosomes, protein and RNA based structures that are responsible for translating genetic information in nucleic acids into proteins

Function:

• structural support

Prokaryotes

Structure:

• network of fibers extending throughout cytoplasm
• 3 main protein fibers

Structure:

• contains a nucleolus
• filled with chromatin
• bounded by Nuclear Envelope

• hydrophobic vs hydrophilic
• selective permeability
• allows oxygen, water, and other small particles to pass through with ease
• larger particles have to pass through the proteins

• maintains shape of the cell
• provides anchorage for organelles

• microtubules

• synthesize lipids, oils, phospholipids, steroids and sex hormones
• hydrolysis of glycogen into glucose
• detoxify drugs and poisons (in liver)

• protein fibers

• thickest
• cell structure and mobility
• consists of tubulin

• double membrane
• contains pores for large macromolecule transportation

• Single-celled organisms that are the earliest and most primitive forms of life on earth
• Do Not Contain a Nucleus and Membraneous organelles

• motility

• microfilaments

• cell locomotion
• cilia, flagella, etc.

• DNA is located in the nuceolide region

Membrane less organelle

Appears as a large dark spot within a nucleus

• regulation

• thinnest
• internal movements within cell
• consists of actin, myosin

• organizes structures and activites of cell

Consists of glycoproteins, glycolipids, phospholipids, cholesterol, peripheral protein, transmembrane proteins, and filaments of cytoskeleton.

• Intermediate filaments

Contain all Bacteria and Archea

• intermediate in size
• more permanent fixtures, specialized for bearing tension
• consists of keratin

Phospholipid bilayer

Plant Cell

Animal Cell

• Within the nucleus, DNA organizes into fibrous material, chromatin

• When the cell divides, chromatin fibers coil up as seperate structures called chromosomes

Membrane Factory

• synthesize membrane phospholipids

• the genes within the chromosomes are the cell's nuclear genome

Have (unlike Animal cells)

• Chloroplasts
• Cell Wall
• Plasmodesmata
• Central Vacuole

Have (unlike plant cells)

• Centrioles
• Lysosomes
• Flagella
• Cilia

• build new membrane
• as ER membrane expands, bud off and transfer to other parts of cell that need membranes

• synthesize membrane proteins

• membrane bound proteins synthesized directly into membrane
• processing to make glycoproteins

Vesicle

Common Organelles for Plant and Animal Cells

Function:

• carrier/transfer ships in the cell

Golgi Apparatus

• Cell Membrane
• Cytoskeleton
• Vesicles
• Mitochondria
• Nucleus

• Ribosomes
• Endoplasmic Reticulum
• Golgi Apparatus
• Nucleolus
• Vacuoles

Vacuoles

Comparison:

• bacteria cells 1-10 microns
• eukaryotic cells 10-100 microns

cis

Peroxisomes

Function:

• finishes, sorts, & ships cell products
• center of manufacturing, warehousing, sorting and shipping
• extensive in cells specialized for secretion (endocrine and exocrine glands)

Ribosomes

Food Vacuoles

Contractile Vacuoles

Central Vacuole:

• Phagocytosis, fuse with lysosomes

• Found in freshwater protists

Digestive enzyme sacs

• breakdown fatty acids to sugars

Mitochondria

In many mature plant cells, not found in animal cells

• found in amimal cells

• pumps excess H2O out of cell

Structure:

• cisternae - flattened membranous sacs
• 2 sides

• easier to transport and use as energy source

Function:

storage

trans

Function:

cellular respiration

produce ATP

Function:

• protien production

Structure:

• contain RNA and protein
• composed of two subunits that combine to carry out protein synthesis
• found in both eukaryotic and prokaryotic cells

• detoxify cell
• produce peroxide (H2O2)

• cis - recieves material by fusing with vesicles
• trans - buds off vesicles that travel to other sites

• must breakdown H2O2 to H2O

Structure:

• 2 membranes

• smooth outer membrane
• highly folded inner membrane (the cristae)

• stockpiling proteins or inorganic ions
• depositing metabolic byproducts
• storing pigments
• storing defensive compounds against herbivores
• selective membrane

• fluid-filled space between 2 membranes

• internal fluid filled space

• Mitochondrial matrix
• DNA, ribosomes, and enzymes

Free Ribosomes

• suspended in cytosol
• synthesize proteins that function within cytosol

All eukaryotic cells have mitochondria

• can vary from 1 to 1000s
• more mitochndria equals more aerobic metabolic activity
• heavily populated in muscle and nerve cells

Semi-Autonomous reproduction and growth

• suggests that they were once by themselves; Endosymbiosis theory

Bound ribosomes

• attached to outside of the endoplasmic reticulum
• synthesize proteins for export or for membranes

• differences between ribosomes in eukaryotic cells and prokaryotic cells
• different proteins and size subunits

Plant Cell Only

Animal Cell Only

Cell Wall

Lysosomes

Plasmodesmata

Function:

• cellular digestion
• recycle materials

Centrioles

Function:

• structural and mechanical support
• provide a chemically buffered environment
• maintain the cell shape
• resistance to pressure of cell
• rate and direction of control growth
• regulate diffusion
• storage of carbohydrates
• cell to cell interactions
• protection against environment

Used in cell division

Structure:

• membrane-bounded sac of hydrolytic enzymes (very sensitive to pH, best at a pH of 5) that digests macromolecules

Microscopic junctions between cells that help facilitate communication and transport of materials between plant cells

• establishes living bridges

Offers direct connection between cells transporting all sorts of materials

• known for transporting proteins, messenger RNA, and viral genomes

• a pair of centrioles organize microtubules

• spindle fibers

• guide chromosomes in mitosis

If not working properly:

• Gaucher's disease
• Schindler's disease
• Tay-Sachs disease

Cellular digestion:

• lysosomes fuse with food vacuoles
• polymers are digested into monomers which are passed to cytosol to become nutrients of cell

Structure:

• most plants have between 1000 - 100,000 plasmodesmata in between cells
• the bridges are 50-60nm wide at the midpoint
• Three layers

• lipids build up in brain cells
• child dies before age 5

Consists mainly of celulose fibers embedded in a network of highly branched carbohydrates

• provides tensile strength

Recycling:

• fuse with organelles or macromolecules in cytosol to recycle materials

• plasma membrane
• cytoplasmic sleeve
• desmotubule

Flagella & Cilia

Chloroplasts

Extensions of Eukaryotic cytoskeletons

• Cilia are numerous and short (hair like)
• Flagella are 1-2 per cell and longer (whip like)

Function:

• photosynthesis
• store chlorophyll
• generate ATP and synthesize sugars

Both move unicellular and smal multicellular organisms by propelling water past them.

• transform solar energy into chemical energy
• produce sugars from CO2 and H2O

Structure:

• an outer and inner membrane
• Stroma - internal fluid-filled space

Flagella:

• undulatory movement

Cilia:

• Oar-like movement

• force generated parallel to flagellum's axis

• DNA, ribosomes and enzymes
• thylakoids - membraneous sacs where ATP is made
• grana - stacks of thylakoids

• alternating power and recovery strokes
• generate force perpindicular to cilia's axis

Self-Autonomous

• like mitochondria
• Endosymbiosis theory