Lecture 7 Flashcards
Function of Smooth ER
Detoxify lipid-soluble and water-soluble substances into water-soluble compounds and synthesize phospholipids and cholesterol
Abundant in steroid-producing cells
What are the two kinds of glycosylation?
N-linked: connection of oligosaccharides to amino group of asp, begins in ER
O-linked: connection of oligosaccharides to hydroxyl group of Thr, Ser, or hydroxylysine, occurs in golgi
What are the 3 pathways to lysosomes?
Endocytosis
Autophagy: worn-out organelles
Phagocytosis
What is cardiolipin?
A phospholipid found in the inner membrane of mitochondria
Complex I of mitochondrial structure
NADH->CoQ reductase
Passes electron to CoQ
Pumps protons into intermembrane space
Complex II of mitochondrial structure
Succinate CoQ reductase
Passes protons and electrons to FADH2
FADH2 passes protons and electrons to CoQ
Complex III of mitochondrial structure
CoQH2->cytochrome c reductase
Receives electrons and protons from CoQ
Pumps protons into intermembrane space
Cytochrome c passes electrons to Complex IV
Complex IV of mitochondrial structure
Cytochrome c oxidase
Passes electrons from reduced cytochrome c to oxygen
Pumps protons into intermembrane space
Complex V of mitochondrial structure
ATP synthetase, consists of two portions
F0 is embedded in the inner membrane and forms a channel for protons
F1 projects into the matrix and is the actual ATP synthetase
What is the primary source of electrons for the electron transport chain?
CO2 & NADH
Aerobic Respiration Gradient
Established through proton translocating activity in the inner membrane associated with the respiratory chain and mitochondrial ATP synthase
Explain the endosymbiotic theory
Mitochondria derived from alpha-proteobacteria which were capable of oxidative phosphorylation
Alpha-proteobacteria engulfed by prokaryotes that could only use anaerobic respiration and did not digest them, instead, used them for oxidative phosphorylation capabilities
Mitochondrial DNA
Circular, multiple copies, few non-universal codons, U in third position can pair with any other bases, comes from maternal inheritance patterns, many genes transposed into nuclear DNA
Perioxisomes
Utilize hydrogen peroxide as a substrate to oxidize other molecules such as ethanol
Oxidize substances to hydrogen peroxide and break down hydrogen peroxide using catalase, synthesize lipids such as cholesterol, synthesize lysine, synthesize bile acids from cholesterol
What is housed in the mitochondrial matrix?
Enzymes for break down of pyruvic acid, fatty acids, & amino acids
Mitochondrial DNA
Production of CO2/NADH
