VMED 5161 - Cellular Metabolism: Mitochondria & Energy Conversion

Exercise intolerance, muscle weakness, fatigue

Abnormal mitochondrial function in dogs can lead to??

- Electromagnetic - light (plants)

- Chemical (eukaryotic cells)

What are the two types of energy found in organisms?

orbitals

Chemical energy is stored in molecular bonds, where it is held in electron ________________

transfer

Breaking and forming chemical bonds leads to energy ___________

Adenosine triphosphate (ATP) -- (ADP + phosphate)

What is the high-energy molecule in eukaryotic cells that releases energy when it is cleaved of phosphate?

Metabolism

What is the sum total of all chemical reactions in cells?

- Anabolic reactions

- Catabolic reactions

What are the two main metabolic pathways?

Anabolic reactions

What reactions result in the formation of larger complex molecules?

- Dehydrations (glucose + glucose = maltose + H2O)

- Reductions (gain of H+ and e-)

What are two examples of anabolic types of reactions?

Catabolic reactions

What kind of reactions breakdown organic molecules to produce energy?

- Hydrolysis - (sucrose = glucose + fructose)

- Oxidation (loss of H+ and e-)

What are two examples of catabolic reactions?

Cellular respiration

What is the process of energy production within the cell and includes glycolysis, a transition reaction, the Krebs cycle, and the ETC?

Cytosol

Where does glycolysis occur?

Mitochondria

Where does the transition reaction occur?

Mitochondrial matrix

Where does the Krebs cycle occur?

Inner mitochondrial membrane

Where is the electron transport chain located?

NAD+

What is an electron carrier that is a water soluble molecule and transports 2 e- and one H+ derived from fat and carbohydrates?

NADH & FADH2

What electron carriers transport e- and H+ form the site of food degradation to the inner mitochondrial membrane?

proton gradient

Electron carriers create a _________________ across the mitochondrial membrane, which can provide energy to make ATP

Glycolysis

What is the cellular degradation of glucose to pyruvate?

2

How many ATP go into glycolysis of a glucose?

4

How many ATP come out of glycolysis of a glucose?

2

What is the net ATP output of glycolysis directly?

2

How many molecules of pyruvate are produced from glycolysis?

8 (2 (direct) + 6 ATP from 2 NADH after ETC)

What is the net ATP production of glycolysis after oxidative phosphorylation?

Catabolic - energy produced

Is glycolysis a catabolic or anabolic reaction?

Type of cell (energy needs)

What dictates the number of mitochondria in a cell?

double

Mitochondria have a __________ membrane

porins

The outer mitochondrial membrane has __________ to allow O2, pyruvate, ATP and other molecules in

ions

The inner membrane of the mitochondria is the site of oxidative phosphorylation and is impermeable to __________ (formed from cardiolipid)

cristae

What are the invaginations of the inner mitochondrial membrane that increase its SA?

Electron transport chains

ATPase complexes (puts together ATPs)

What machinery for energy production is included in the inner membrane?

proton

The intermembrane space of the mitochondria has a high ________ concentration

- Enzymes for Krebs cycle and ETC

- Mitochondrial DNA (maternal)

What are the components of the mitochondrial matrix?

- Energy production

- Thermogenesis

- Oxidant production

What are the 3 main functions of the mitochondria?

Glucose -> pyruvate

Fat -> fatty acids

Proteins -> amino acids

What are the substrates that can be used for energy production in the mitochondria?

O2-, H2O2, ONOO-

What are the oxidants that can be produced by the mitochondria?

releases cytochrome C from intermembrane space via pores of the mitochondrial membrane

How are the mitochondria involved in apoptosis?

redox

Mitochondria are involved in the regulation of the cellular ______ state and in intracellular signaling

ATP

Name the high-energy molecule that is the source of energy readily available to the cell

Pyruvate (from glycolysis)

What is the substrate of the transition reaction?

Acetyl CoA

What is the product of the transition reaction?

Acetyl Coa

What is the substrate for the Krebs cycle?

Electron carriers

What carries the energy released by the Krebs cycle to the ETC in the inner membrane?

ATP synthase

Since the H+ ions cannot flow back across the inner membrane, what complex must they go through to balance (and also produce ATP)?

Oxidative decarboxylation

What is another term for the transition reaction, where the two pyruvates from glycolysis are converted to acetyl CoA?

2 NADH2 (6 ATP after ETC)

What is the energy production of the transition reaction?

3 NADH, 1 FADH2, 1 ATP

What is the energy production of one cycle of the CAC?

6 NADH, 2 FADH2, 2 ATP (multiply one cycle by 2 acetyl CoA)

After ETC - 24 ATP

What are the products of Krebs cycle from one glucose?

Passage of e- to the different complexes in the chain releases energy to pump protons into intermembrane space

How is the energy for creating the proton gradient from the ETC produced?

Oxidation on one side of the membrane provides the energy to phosphorylate ADP into ATP (coupled with proton motive force)

Why is it called oxidative phosphorylation?

36-38 ATP per glucose

What is the ATP yield for one glucose?

Energy conversion from triglycerides or proteins (different pathways to make carriers)

What happens if there is no glucose available?

2

What is the direct ATP yield for the Krebs cycle?