1. What are the types of fibers all human muscles contain?
All human muscles contain slow and fast fibers, but muscles differ int he percentage of each.
2. What are the three main stages of cellular respiration?
The three main stages of cellular respiration are: glycolysis, the citric acid cycle, and the oxidative phosphorylation.
3. What is the movement of electrons from one molecule to another called?
It is called oxidation-reduction reaction, or redox reaction.
Five main factors from the reading:
1. Photosynthesis and cellular respiraton provide energy for life.
2. Cellular respiration banks energy in ATP molecules.
3. The human body uses energy from ATP for all its activities.
4. Glycolysis harvests chemical energy by oxidizing glucose to pyruvate.
5. Pyruvate is chemically groomed for the citric acid cycle.
Diagram:
In cellular respiration, electrons fall down an energy staircase and finally reduce oxygen. Electron transport chain also controls the release of energy for synthesis of ATP.
Link: http://www-3.unipv.it/webbio/anatcomp/freitas/2008-2009/biocell_BT08-09.htm
Summary:
The introduction section of the chapter talks about the difference between a marathoner and a sprinter. It says that the main difference between these two is that the sprinters have more fast fibers, and the marathoners have more more slow fibers. The introduction also gives us a brief definition of cellular respiration - the aerobic harvesting of energy from sugar by muscle cells or other cells.
Photosynthesis and cellular respiration provide energy for life. Breathing supplies oxygen to our cells for use in cellular respiration and removes carbon dioxide. When we breathe we take in oxygen and breathe out less oxygen and more carbon dioxide. The oxygen helps our cells work properly. Cellular respiration banks energy in ATP molecules. Glucose and oxygen combine together and produce carbon dioxide, water and ATP. The human body uses energy from ATP for all its activities. Energy units are called kilocalories (kcal). Cells tap energy from electrons "falling" from organic fuels to oxygen. The movement of electrons from one molecule to another is an oxidation-reduction reaction, or redox reaction for short. In a redox reaction, the loss of electrons from one substance is called oxidation, and the addition of electrons to another substance is called reduction. Two key players in the process of oxidizing glucose are an enzyme called dehydrogenase and a co-enzyme called NAD+. In cellular respiration, electrons fall down an energy staircase and finally reduce oxygen. This is called electron transport chain. Cellular respiration occurs in three main stages: glycolysis, the citric acid cycle and oxidative phosphorylation. Glycolysis harvests chemical energy by oxidizing glucose to pyruvate. This happens in substrate-level phosphorylation where an enzyme transfers a phosphate group from a substrate molecule directly to ADP, forming ATP. This process produces a small amount of ATP in both glycolysis and the citric acid cycle. Pyruvate is chemically groomed for the citric acid cycle. The citric acid cycle completes the oxidation of organic molecules, generating many NADH and FADH2 molecules. Most production of ATp occurs by oxidative phosphorylation though, and glycolysis and the citric acid cycle's mission is the help this. The last step of the oxidative phosphorylation ATP synthases. In chemiosmosis, the potential energy of H+ concentration gradient is used to make ATP. The concentration gradient drives the diffusion of H+ through ATP synthases, protein complexes built into the inner membrane that synthesize ATP. Certain poisons though might interrupt critical events in cellular respiration. Some of them are rotenone, cyanide, carbon monoxide, DNP, and oligomycin. Each molecule of glucose yields many molecules of ATP. Fermentation enables cells to produce ATP without oxygen. Our muscle cells, a few other cell types, and certain bacteria can regenerate NAD+ by a process called lactic acid fermentation. Another type of fermentation is the alcohol fermentation, used in brewing, wine making, and baking. Glycolysis evolved early in the history of life on Earth. Ancient prokaryotes probably used it to make ATP long before oxygen was present in Earth's atmosphere. Cells use many kinds of organic molecules as fuel for cellular respiration, which means that eating certain kinds of food yields ATP to our body. Food molecules provide raw materials for biosynthesis.
Key Terms:
1. Redox reaction - the movement of electrons from one molecule to another.
2. Oxidation - the loss of electrons from one substance.
3. Reduction - the addition of electrons to another substance.
4. Electron transport chain - controls the release of energy for synthesis of ATP, and it helps electrons move.
5. Substrate-level phosphorylation - an enzyme transfers a phosphate group from a substrate molecule directly to ADP, forming ATP.
6. Intermediates - the compounds that form between the initial reactant, glucose, and the final product, pyruvate.
7. Lactic acid fermentation - a process by which muscle cells, a few other cell types, and certain bacteria can regenerate NAD+.
8. Facultative anaerobe - can make Atp either by fermentation or by oxidative phospohorylation, depending on whether oxygen is available.
9. NAD+ - nicotinamide adenine dinucleotide is an organic molecule that cells make from the vitamin niacin and use to shuttle electrons in redox reactions.
10. Dehydrogenase - a key enzyme in the process of oxidizing glucose.
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