Non-membranous Organelles

Non-membranous Organelles

Presaented by- Dr. Subarna DasResident, Dept. of Anatomy, BSMMU

Guided by-Dr. Zinnat Ara YasminAsst. Prof, Dept. of Anatomy, BSMMU

Objectives• Describe the nonmembranous

organelles of a typical cell with their structure and specific functions.

• Summarize the process of protein synthesis.

Cell Organelles

Organelle= “little organ”

Non-membranous Organelles

1.Ribosomes2.Centrioles3.Cytoskeletons- Microfilaments Intermediate filaments Microtubules4.Proteasomes

Ribosome• Site of protein synthesis

• Found attached to rough ER or floating free in cytosol

• Produced in a part of the nucleus called the nucleolus

Types of RibosomesRibosome

Free Ribosome Polysome

TypesRibosome

Synthesis of ProteinRibosome

Synthesis of ProteinRibosome

Proteasomes

Proteasomes

Structure of proteasomes Proteasomes

a

c

Proteasomes

Cytoskeleton

Microfilaments, Microtubules form “Skeleton” of the cell

Cytoskeleton

MicrotubulesMicrofilaments

(Actin Filaments)Intermediate

Filaments

Structure of CytoskeletonCytoskeleton

Cytoskeleton

MicrofilamentsCytoskeleton

Structure of MicrofilamentCytoskeleton

Function of MicrofilamentCytoskeleton

Cytoskeleton

Function of MicrofilamentCytoskeleton

Function of Microfilament

Cytoskeleton

Function of MicrofilamentCytoskeleton

Intermediate Filament Cytoskeleton

Is similar to Anchor

Intermediate FilamentCytoskeleton

MicrotubulesCytoskeleton

analogya microtubule

is similar torailroad tracks

Microtubules

Cytoskeleton

The flagella and cilia are composed of microtubules

MicrotubulesCytoskeleton

Cilia & Flagella Structure

• Bundles of microtubulesWith plasma membrane

MicrotubulesCytoskeleton

Microtubules

Cytoskeleton

Microtubules

Cytoskeleton

Microtubules

Cytoskeleton

Microtubules

Cytoskeleton

Examples of cytoskeletal pathologies

• Immotile cilia syndrome (Kartagener’s synd.) Bronchiectasis

• Decreased sperm motility Sterility

• Neurofibrilary tangle Alzheimer’sdisease

•Desminopathy

Cytoskeleton

Centriole• Aids in cell division• Usually found only in

animal cells• Made of microtubules

Fig. 6-22Centrosome

Microtubule

Centrioles0.25 µm

Longitudinal section of one centriole

Microtubules Cross sectionof the other centriole

Centriole

Structure of CentrioleCentriole

Structure of Centriole

Centriole

Centrioles in cell division Centriole