How do mitochondria generate energy?
from breakdown of lipids and carbohydrates
How do chlorplasts generate energy?
use sunlight energy to generate ATP and reducing power to synthesize carbohydrates from CO2and H2O.
What are Peroxisomes?
contain enzymes involved in a variety of metabolic pathways.
Discuss genome within powerhouse organelles
-Mitochondria and chloroplasts have their own genomes and include some genes that are transcribed and translated within the organelle
Describe the structure of Mitochondria
a) surrounded by double membrane system
b) inner and outer membranes are seperated by an intermembrane space
c) inner membrane has cristae folds that extend into the interior matrix
What is found in the matrix of mitochondria?
a) genetic system
b) pyruvate
c) enzymes for oxidative metabolism
What is Pyruvate?
- from glycolysis process
- transported to mitochondria
- completely oxidizes to CO2 which
- yields bulk of energy (ATP) of glucose metabolism
Where does Glycolysis occur?
-occurs in the cytosol of mitochondria
What happens as pyruvate interacts with coenzyme A?
a) Pyruvate undergoes oxidative decarboxylation
b) Pyruvate + CoA-SH –>acetyl CoA; generates 2NADH
What happens to Acetyl CoA once it is generated?
a) Acetyl CoA enters the citric acid cycle
b) The two carbon acetyl group combines with oxaloacetate (4C) to yield citrate (6C)
c) remaining 2C’s of citrate are completley oxidized to CO2 and oxaloacetate is regenerated
What results from the breakdown of 2 citrate carbons
a) 2 CO2
b) 1 oxaloacetate
c) GTP
d) 3 NADH
e) 1 FADH2
What results from the oxidation of glucose at the end of the citric acid cycle (include products from previous processes)?
- 6 molecules of CO2
- 4ATP
- 10 NADH
- 2FADH2
What is the total energy yield from oxidation of glucose?What stages are they from?
A) 36-38 ATP
a)glycolysis: 2ATP, 2NADH
b) Kreb’s: 2 ATP, 8 NADH, 2 FADH2
c) oxidative phosphorylation: each NADH yields 3 ATP, each FADH2 yields 2 ATP
B) Total: 2 ATP + 2ATP + 103(NADH) + 22(FADH2) = 38
Describe process of transport for electrons from FADH2?
a) complex 2 receives electrons from the citric acid cycle intermediate succinate
b) electrons are transferred to FADH2 and then to coenzyme Q
What is the energy level of electrons in NADH and FADH2?
high energy
Energy derived from NADH and FADH is transported through the ____ by ___during ETC
the membrane by molecular oxygen
What happens to energy derived from ETC process?
energy derived is converted to potential energy and is stored in a proton gradient which drives ATP synthesis
Give summary of characteristics of inner membrane of mitochondria
a) principal site of ATP generation
b) surface area is increased by cristae folds
c) contains a high percentage of proteins involved in oxidative metabolism & transport
d) impermeable to most ions and small molecules
Give summary of characteristics of the outer mitochondrial membrane
a) highly permeable to small molecules
b) contains porins, which form channels that allow the free diffusion of small molecules
c) composition of the intermembrane space is similar to the cytosol
Where is the mitochondria usually found within eukaryotic cells?
position is often near locations of high-energy use, such as synapses in nerve cells
Describe a mitochondrial network
-in most cells mitochondria from an interconneted network and are constatntly fusing and dividing to remodel this network which in turn modifies mitochondrial morphology and function