MITOCHONDRIAL DNA ANALYSIS

Outline the contribution of mitochondria to the cellular energy budget. Comment on the ethical implications of mitochondrial DNA analysis

Outline the contribution of mitochondria to the cellular energy budget. Comment on the ethical implications of mitochondrial DNA analysis

Introduction

If placed in the perspective of the overall energy budget for a cell, the ATP requirements for operating the cell death pathways are likely to be small. The main consumers of cellular energy in the basal state are three processes. The metabolic cost of active transport by the Na+/K+-ATPase for the maintenance of ion gradients averages 36% of the basal metabolic rate across many cell types (Brand, 2005, 897).

Consequently, initiation and execution of apoptosis are unlikely to represent even a noticeable fraction of the energy budget. In the latter phases of cell death, when various physiological processes have been disrupted, the relative cost of cell death processes within the cellular energy budget undoubtedly increases. Unfortunately, a quantitative inventory of how much ATP is utilized during apoptosis is not available.

Why cells need energy

Cells perform processes such as synthesis, photosynthesis, dna replication, and protein and need energy to do so. A cell gets its energy from food sugars, fats, and proteins and a cells food is glucose. If a cell doesn't have energy it will die. Organelle needs energh so if one isn't functioning in a cell it will die.

Sources of energy that cells can utilise for cellular respiration

The point of cellular respiration is to harvest electrons from organic compounds such as glucose and use that energy to make a molecule called ATP. ATP in turn is used to provide energy for most of the immediate work that the cell does. ATP can be thought of as being like a small package of energy that has just the right amount of energy that can be used in a controlled manner.

Overview of cellular respiration processes - glycolysis, citric acid cycle and electron transport chain (ETC)

Cellular respiration is the process by which food is broken down by the body's cells to produce energy, in the form of ATP molecules. In plants, some of this ATP energy is used during photosynthesis to produce sugar. These sugars are in turn broken down during cellular respiration, continuing the cycle (Kauppinen, 1986, 165).

Glycolysis

Glycolysis involves the breaking down of glucose molecules from carbohydrates into molecules of pyruvate, which will continue on to the Krebs Cycle. This process occurs in the cytosol of the cell and can proceed regardless of the presence of oxygen. In the first stage of glycolysis, energy is actually used to phosphorylate the 6-carbon glucose molecule.

The Electron Transport Chain

Very little energy has been produced during glycolysis and the Krebs Cycle. Most of the energy locked in the original glucose molecule will be released by the electron transport chain and oxidative phosphorylation. The electron transport chain is a network of electron-carrying proteins located in the inner membrane of the mitochondrion (Brookes, 2005, 23).

Citric Acid

The Citric Acid Cycle or Krebs Cycle begins after the two molecules of the ...