Isfa: (8) Mitochondria, Peroxisomes & Lysosomes

Front 1

Mitochondria:
-location
-membrane number
-functions of membranes

Back 1

Present in ALL mature eukaryotic cells (except RBC)
-outer: voltage dependent transport, permeable to water & small molecules; has receptors and enzymes.
-inner: impermeable, which allows ATP production by creating a steep electrochemical H+ gradient.

Front 2

Porins

Back 2

Make up voltage dependent transport channels on the outer membrane of the mitochondria. They allow small molecules to permeate through the membrane.

Front 3

Cardiolipin

Back 3

A phospholipid present in high quantities in the inner membrane.

Front 4

Cristae

Back 4

Folds of the inner mitochondrial membrane, these increase membrane surface area.

Front 5

Intermembrane Space

Back 5

Area between the inner and outer membrane.

Front 6

Mitochondrial Matrix

Back 6

Within the inner membrane, electron dense. Contains the enzymes of the citric acid cycle, enzymes of B-fatty acid oxidation, circular mitochondrial DNA, ribosomal RNA, tranferase RNA, messenger RNA and enzymes for mitochondrial protein sysnthesis. Also contains granules for accumulation of cations (Ca).

Front 7

Mitochondrial Functions

Back 7

1. ATP synthesis
2. Beta oxidation of fatty acids
3. Steriod hormone synthesis
4. Elongation of fatty acid chains
5. Ca2+ storage
6. Initiation of apoptosis from within cell

Front 8

Peroxisome Functions

Back 8

1. Oxidize organic substrates and generate hydrogen peroxide
2. Destroy H2O2, enzymes that create H2O2 are segregated in the peroxisome
3. The long chains on FA are shorted by perioxisomes before beta oxidation takes place

Front 9

Early & Late Endosomes

Back 9

Ingested material is enclosed by a plasma membrane and formed into an endocytotic vesicle. The vesicle then fuses with an early endosome and then with a late endosome. This matures into a lysosome by fusing with vesicles that contain lysosomal enzymes.

Front 10

Residual Bodies

Back 10

E.g. lipofuscin; indicates aging. Includes indegestible material that remains in lysosomes.

Front 11

Lysosome Functions (list)

Back 11

1. Degrades wornout or excess organelles by autophagy
2. Digestion of material taken into cells
3. Thyroid hormone secretion
4. Resorption of bone by osteoclasts includes both secretion of lysosomal enzymes & phagocytosis
5. Tissue remodeling
6. Source of cell nutrients in starvation

Front 12

Receptor Mediated Endocytosis

Back 12

Uptake of specific molecules into the cell induced by ligand binding to specific receptors on the cell surface.

Front 13

Ubiquitin

Back 13

Small polypeptide used to mark proteins that need to be destroyed by proteasomes.