ORGANELLES:CENTROSOME

• Function: Microtubule formation- Two centrioles and

pericentriolar area- Microtubule organizing

center- Cilia and flagella are

composed of microtubules

Figure: 3.17

ORGANELLES:CILIA

• Many per cell• Short hairlike projections• Bundles of microtubules in PM

projections• Function: Move substances along

the outer cell boundary (one way)

Figure 3.15

ORGANELLES:FLAGELLUM

• One per cell• Long bundle of microtubules

enclosed in PM• Propels the entire cell (sperm)

Figure 3.15

ORGANELLES:RIBOSOMES

• Non-membrane bound• Site of protein synthesis

- Composed mainly of RNA (rRNA)• Formed in the nucleolus• Located in the cytosol, or attached

to the nucleus or ER

Figure 3.19 http://www2.prs.k12.nj.us/Schools/PHS/Science_Dept/APBio/Ribosome.html

ORGANELLES:ENDOPLASMIC RETICULUM

(ER)Rough ER• Long, interconnected

flattened sacs of membrane

• Studded with ribosomes for protein synthesis

• Produces secretory & membrane proteins, plus phospholipids

Figure: 3.17

ORGANELLES:ENDOPLASMIC RETICULUM

(ER)Smooth ER • More tubular• No ribosomes• Produces

phospholipids, fats, steroids

• May perform vastly different functions depending on cell type (i.e., muscle vs. liver) Figure: 3.17

Figure: 3.18

ORGANELLES:GOLGI COMPLEX• Flattened sacs (cisternae)• All secretory proteins pass

through GC• More protein modifications (carb,

lipid additions)

Figure: 3.19

ORGANELLES:GOLGI COMPLEX

• Proteins are packaged into vesicles with one of three possible destinations:- Secretory

vesiclessecretion- Membrane

vesiclesplasma membrane

- Transport vesiclesother organelles

ORGANELLES:LYSOSOMES

• Storage/digestive vesicles formed by GC- Contain a variety of

digestive enzymes• Slightly acidic - pH 5

- Proton pumps for H+• Main functions –

- Digestion of substances that enter the cell• Transport byproducts to

cytosol- Digest old organelles

(autophagy)Figure: 3.20

http://bioweb.wku.edu/courses/biol22000/11Organelles/Fig.html

ORGANELLES:PEROXISOMES

• Protect cell from harmful effects of oxidation products

• Contain oxidizing enzymes (oxidases) for detoxifying substances- Hydrogen peroxide (toxic) is a

byproduct of oxidations- Peroxisomes contain catalases to

convert hydrogen peroxide to water

http://bioweb.wku.edu/courses/biol22000/11Organelles/Fig.html

ORGANELLES:MITOCHONDRIA

• Function: ATP production (cellular respiration)- Number of mitochondria in a cell depends

on its ATP demands• Double-membraned organelle

- Outer mt membrane- Inner mt membrane with folds (cristae)

• Large surface area for cellular respiration- Matrix

Figure: 3.21

Cell Overview

• Plasma Membrane – phospholipid bilayer

• Cytoplasm • Cytosol = intracellular fluid• Organelles = “cell’s organs”

• Nucleus – contains chromatin

NUCLEUS• Typically one per

cell• Stores DNA

http://www.nimr.mrc.ac.uk/virology/doorbar/function/fig2/

Figure 3.22

NUCLEUS

• Nuclear envelope: double membrane that encloses the nucleus- Nuclear pores control

entrance/exit of substances• Active transport of large

molecules• Diffusion of small

molecules• Nucleoli: areas within

the nucleus where ribosome assembly occurs