Isf A Lecture 8: Mitochondria, Peroxisomes, Lysosomes

Front 1

Mitochondria: general function

Back 1

Main function: convert chemical fuels into energy from that drive cellular reactions ex: ATP syn via oxidative phosphorylation

Front 2

Mitochondria:
- location
- membrane number
-functions function of membrances

Back 2

present in ALL mature eukaryotic cells (except RBC)
-2
- outter: voltage depent transport - permeable to water, small molecules. has receptors and enzymes
-inner: impermeable, which allows ATP production by creating a steep concentration and electrical gradient

Front 3

Porins

Back 3

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

Front 4

cardiolipin

Back 4

phospholipid should in the inner membrane. it is impermeable to most small molecules and ions. have ion pumps and transport systems.

Front 5

cristae

Back 5

folds of the inner mitochondrial membrane.
-increases membrane surface.

Front 6

intermembrane space

Back 6

area between teh iner and outer membrane

Front 7

matrix

Back 7

internal to the inner membrane, relatively electron dnse
-soluble enzyme sof the citric acid cycle (krebs)
-enzymes of B-fatty acid oxidation
- close circular double stranded mitochondrial DNA
-ribosomal RNA
-tranferase RNA
-messenger RNA
-enzymes for mitochondrial protein sysnthesis

Front 8

Mitochondria functions

Back 8

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 9

Perioxisomes
general function
- number of membrance

Back 9

also called microbodies
- break down cytotoxic hyrogen peroxide and site of oxygen utilization
-1

Front 10

Perioxisomes functions

Back 10

1. oxidize organic substrates and generate hydrogen peroxide, ex: alcohol
2. destroy h2o2, enzymes that creat h2o2 are segregated in teh perioxisome
3. the long chains on FA are shorted by perioxisomes before b oxidation takes place

Front 11

Lysosome
# of membrane
pH

Back 11

degrade macromolecules with hydrolytic enzymes
- 1
- 5

Front 12

vesicular transport

Back 12

how lysosomes move substances from one cellular compartment to another

Front 13

endocytosis

Back 13

the engulfing of a substance into the cell

Front 14

early and late endosomes

Back 14

ingested material is enclosed by a plasma membrance and formed endocytic vescile. The vesicle then fuse with a early endosome and then to late endosome which mature into a lysosome by their fusion with vessicles that contain lysosomal enzymes.

Front 15

residual bodies

Back 15

-aka, lipofuscin - indicates aging
-indegestible material that remains in lysosomes

Front 16

Lysosome functions:

Back 16

1. degrades wornout or excess organelles by autophagy
2. digestion of material taken inot cells
3. thyroid hormone secretion
4. resorption of bone
5. tissue remodeling
6. source of cell nutrients in starvation

Front 17

endocytosis

Back 17

the process in which fluid and macromoleculees enter the cell

Front 18

pinocytosis

Back 18

cell drinking - ingestion of fluid and small proteins by the formation of vesicles at the cell surface

Front 19

receptor mediated endocytosis

Back 19

uptake of specific molecules into the cell, ligand must bind to receptor on teh cell surface

Front 20

phagocytosis

Back 20

eating by cells. cell processes surround solid materials and fuse together to form vesicle. Then then fuse with a lysosome too.

Front 21

autophagy

Back 21

intracellular proteins are degraded by lysosoems

Front 22

proteasomes

Back 22

large multienzyme protease complexes that breakdown single proteins in the cytoplasm

-barrel shaped particles

Front 23

ubiquitin

Back 23

small polypeptide used to mark proteins that needs to be destroyed by proteasome.