Cairnleigh M. Dizon August 26, 2014 BSED 1A NAT SCI 1 CELLULAR RESPIRATION
-is the set of metabolic reactions and processes that take place in the cells of organisms to convert biochemical energy from nutrients into adenosine triphosphate (ATP), and then release waste products. The reactions involved in respiration are catabolic reactions, which break large molecules into smaller ones, releasing energy in the process as weak so-called "high-energy" bonds are replaced by stronger bonds in the products. Respiration is one of the key ways a cell gains useful energy to fuel cellular activity. Cellular respiration is considered an exothermic HYPERLINK "http://en.wikipedia.org/wiki/Redox" \o "Redox" redox reaction which releases heat. The overall reaction occurs in a series of biochemical steps, most of which are redox reactions themselves. Although technically, cellular respiration is a combustion reaction, it clearly does not resemble one when it occurs in a living cell due to slow release of energy from the series of reactions.
3 STAGES OF CELLULAR RESPIRATION GLYCOLYSIS
Glycolysis is the first of the three steps used to breakdown glucose to produce ATP. Glucose, a 6 carbon sugar, is split into two 3 carbon sugars. The 3 carbon sugars are then oxidized and their remaining atoms reaarranged to form two molecules of pyruvate. There are 2 distinct phases of Glycolysis:
1.PREPARATORY PHASE: Energy in glucose cannot be readily released unless energy from ATP if added first. In this phase, 2 ATP are added to the reaction, producing a glucose molecule with two phosphate groups. The phosphate groups make glucose less stable and ready for chemical breakdown. 2. PAY-OFF PHASE: Investment of energy in prepatory phase is paid back with interest! 4 ATP and 2 NADH molecules are formed and as well as two molecules of pyruvate.
The end product of Glycolysis, pyruvate, is transported into the mitochondrion and converted to a compound called acetyl coenzyme A or acetyl CoA. This conversion of pyruvate to acetyl CoA also results in the transfer of electrons to NAD+, storing energy in the form of NADH. The Krebs Cycle consists of nine enzyme-catalyzed reactions that can be divided into 3 stages: 1. Acetyl CoA binds a four carbon molecule (oxaloacetate) producing a six carbon molecule (citrate). 2. Two carbons are removed as carbon dioxide.
3. The four carbon starting material is regenerated.
The Krebs Cycle generates ATP and many energized electrons (in the form of FADH2 and NADH) for the electron transport chain.
ELECTRON TRANSPORT CHAIN
The mitochondrial electron transport chain is similar to that used in chloroplasts for photosynthesis. NADH and FADH2 molecules formed during Glycolysis and Krebs Cycle carry their electrons to the electron transport chain. The electron transport chain creates a proton gradient that ultimately leads to the production of a large 1076960346075amount of ATP.
The action of the electron transport chain can be summarized as follows: 1.Electrons (in the form of NADH and FADH2) harvested from Glycolysis and Krebs Cycle are carried to the transport chain.
2. Electrons provide the energy to pump protons from the mitochondrial matrix to the inter membrane space. This creates a steep proton gradient across the inner mitochondrial membrane. 3. Oxygen joins with protons and electrons to form water.
4. Protons diffuse back down their concentration gradient, through ATP synthesis, driving the synthesis of ATP. Most of the ATP generated by cellular respiration is made by the electron transport chain. DIFFERENCE BETWEEN CELLULAR RESPIRATION AND PHOTOSYNTHESIS All living things require a constant supply of energy in order to survive. One method of how animals derive this energy is through the process of cellular respiration. Cellular respiration is the process in which energy from different food sources are broken down in order to provide just the right amount of energy for the organism to be able to perform a particular set of activities. During cellular respiration, organic compounds, such as glucose, which are derived from the organism’s food source, are converted into Adenosine Tri-Phosphate (ATP) molecules. These molecules serve as energy packets that are stored within the cells of the organism to be used when the need arise. Cellular respiration may either be aerobic or anaerobic. The difference between the two is that aerobic cellular respiration utilizes oxygen to convert organic compounds into energy while anaerobic cellular respiration converts the organic compounds into energy without the use of oxygen during the process. Plants derive their supply of energy through a process called photosynthesis. Unlike cellular respiration whereby the process only entails the harvesting of energy from different foods consumed by the organisms, photosynthesis involves the conversion of one type of energy into another form of energy which could then be used by the plant organism. Photosynthesis is a cellular process where light energy coming from the sun is converted into chemical energy with the help of chlorophyll pigments found on the plant’s leaves. This chemical energy is then stored in the plant cells through the form of sugar bonds, hence the name of the chemical process. It is these sugar bonds that animal organisms convert into usable energy through the process of cellular respiration. http://en.wikipedia.org/wiki/Cellular_respirationhttp://www.hartnell.edu/tutorials/biology/cellularrespiration.htmlhttp://www.differencebetween.net/science/difference-between-cellular-respiration-and-photosynthesis/Discrimination against women is defined as any distinction, exclusion or restriction made on the basis of sex which has the effect or purpose of impairing or nullifying the recognition, enjoyment or exercise by women, irrespective of their marital status, on a basis of equality of men and women, of human rights and fundamental freedoms in the political, economic, social, cultural, civil or any other field Women have generally had a lower status than men throughout history. Men tend to occupy leadership positions in all societies, including very primitive ones. Having babies slows women down. The degree to which women have been discirminated against has varied greatly from society to society. I think the roots of it are in biology. Men tend to be more assertive than women, and more anxious to achieve dominance than women are. Everyone can do something to stop discrimination. Practicing simple acts every day will help you strengthen your skills to intervene when needed. Most people are not actively seeking to harm others, but many people will admit, they stood by when someone else was hurt because they didn’t know what to do or say. . Identify what you believe. Know where your beliefs originated and why they are important to you, your family and/or your friends. 2. Challenge yourself. Try to meet someone new. Try a different restaurant or coffee shop. Walk down a different street. Expand your world view by expanding your world. 3. Ask questions. Promote dialogue, but don’t engage in diatribes. Recognize that what has been done before is not always what is needed now. Why is it done that way? What is the history? Can you tell me more about that? 4. Listen. Seek to understand another perspective before judging it as wrong or strange. Try to understand the beliefs of someone from another faith or political party. Listen to the language used around you. Does it label or offend others? 5. Practice inclusion. Is there room for every voice at your staff meeting? Is every child included in the party? Have you listened to a teen lately? Have you asked an elder for their advice? Do you have a friend from another ethnicity or religion? Celebrate common ground and differences. 6. Speak up against injustice. Injustice happens in other countries, in other states and still in our own backyards. Whether its social, environmental, racial, legal, economic or other forms of injustice, use your voice to name the problem and begin to create change. 7. Take action. Don’t just think about equality, justice and inclusion. Take action to make it a reality. 8. Promote change. Change your mind and see what happens. Start with yourself and it is easier to ask others to change. 9. Be intentional. Do and say what