Mitochondria and monomers/polymers?

Question

1. How is the mitochondria responsible for completing the breakdown of glucose to get energy?

2. The four macromolecules of life are carbohydrates, lipids, proteins, and nucleic acids but how do I explain what the monomers are for each polymer? (I don't quite understand what it's asking)

Answer 1

Glycolysis takes place in the cytosol and passes pyruvate to the pyruvate oxidation pathway that supplies acetyl-CoA to the mitochondria where it is further oxidized via the citric acid cycle (also known as the tricarboxylic acid cycle, the TCA cycle, or the Krebs cycle).

The citric acid cycle begins with Acetyl-CoA transferring its two-carbon acetyl group to the four-carbon acceptor compound, oxaloacetate, forming citrate, a six-carbon compound.

The citrate then goes through a series of chemical transformations, losing first one, then a second carboxyl group as CO2.

Most of the energy made available by the oxidative steps of the cycle is transferred as energy-rich electrons to NAD+, forming NADH. For each acetyl group that enters the citric acid cycle, three molecules of NADH are produced.

Electrons are also transferred to the electron acceptor FAD, forming FADH2.

At the end of each cycle, the four-carbon oxaloacetate has been regenerated, and the cycle continues. Products of the first turn of the cycle are one GTP, three NADH, one FADH2, and two CO2.

Because two acetyl-CoA molecules are produced from each glucose molecule, two cycles are required per glucose molecule.

At the end of all cycles, the products are two GTP, six NADH, two FADH2, four CO2.


Finally, an electron transport chain (also called electron transport system (ETS) or electron transfer chain (ETC)) is a series of membrane-associated electron carriers mediating biochemical reactions that produce adenosine triphosphate (ATP), which is the energy currency of life. Electrons from the two energy-rich electron donors, NADH and FADH2 from the TCA cycle are passed through an electron transport chain to oxygen, which is reduced to water. This is a multi-step redox process that occurs on the mitochondrial inner membrane. The enzymes that catalyze these reactions have the remarkable ability to simultaneously create a proton gradient across the membrane, producing a thermodynamically unlikely high-energy state with the potential to do work.

2. Carbohydrates can be simple sugars or the sugars can be linked together to form polysaccharides (poly=many; saccharide=sugar). These are simple sugars linked together head-to-toe to form chains and branched chains. Examples are starch, cellulose, pectin, etc. In the case of both starch and cellulose the monomers are glucose, while pectin (the polymer that gels the jam you put on toast) is a polymer of galacturonic acid.

Lipids are made up a bit differently, where a 'head group' usually glycerol or a related compound, has several (usually 3) fatty acids attached. See, for more details: http://biology.clc.uc.edu/Courses/bio104/lipids.htm

Proteins are made up of amino acids. Amino acids are, as the name implies, compounds with two functional groups - an amino group and a carboxylic acid group. These two functional groups bond together with the loss of water to form a special type of amide bond called a 'peptide bond' - here again it is a head-to-toe linkage. Typically proteins are linear polymers (although they can be crosslinked after being made, the products from synthesis by the ribosomes is always a linear straight chain).

Finally, nucleic acids form the genetic polymers of DNA and RNA. These are built in a more complex array of phosphodiester linkages and a sugar backbone. Better to surf to a web site like:

http://www.rothamsted.ac.uk/notebook/courses/guide/dnast.htm

I hope this helps...

Answer 2

1. The mitochondria are involved in the stages of aerobic respiration that occur following glycolysis. The inner membrane of the mitochondria has the molecules of the electron transport chain where the big ATP pay-off happens.

2. The monomers of a polymer are the basic building blocks that make up the polymer.
Carbohydrates - monosaccharides
Lipids - glycerol and fatty acids
Proteins - amino acids
Nucleic acids - nucleotides

Answer 3

The mitochondria makes ATP from the glucose, which goes to different parts of your body to make energy. The monomer is the individual molecule that is repeated to make up the polymer. I hope this helps

Answer 4

Could you possibly imagine what it would be like if we had no electricity in our city? Things would come to a standstill. The mitochondria, tiny bean-shaped organelles, act as power plants to provide up to 95 percent of the body's energy needs for cellular repair, movement, and reproduction. As a city's need for power increases, more power plants are built. Similarly, if a given cell type is very active and needs more power, there are a larger number of mitochondria in that cell. Liver cells, which are quite active can have up to 2,000 mitochondria in each cell. Sperm Cells swim with a tail (flagellum), so they need only a single mitochondria coiled around the tail for energy. Special enzymes in the mitochondria helto to take in oxygen and use it to produce energy. While our city uses electricity for most of its power, the cell uses adenosine triphosphate *ATP which is created by the mitochondria