Chapter 4.2 pages 74-80
Cellular Respiration Cellular respiration changes energy in bonds of food into energy that cells can use.
Structure of ATP Adenosine triphosphate or ATP stores energy in its bonds. ATP is a nucleotide triphosphate. ATP has a nitrogenous base adenine, a sugar and 3 phosphates. Each phosphate has a negative charge.
Phosphorylation ATP transfers a phosphate to another molecule and energizes that molecule.
ATP & Cellular Work ATP helps with mechanical work, transport work, and chemical work. An example of mechanical work is cell movement. An example of transport work is moving substances across a membrane from low to high concentration. An example of chemical work is breaking down substrates using enzymes.
Regenerating ATP During cellular respiration, ATP is regenerated from ADP and phosphate.
Aerobic Respiration Aerobic respiration is cellular respiration that needs oxygen.
Cellular Respiration Breathing = Respiration Our cells go through cellular respiration.
Overview of Cellular Respiration
Electron Carrier One electron carrier used by cellular respiration is nicotinamide adenine dinucleotide (NAD + ). NAD + picks up electrons. NAD + picks up a hydrogen atom and becomes NADH. A hydrogen atom contains 1 H + ion and 1 electron.
Stages of Cellular Respiration 1. Glycolysis 2. The Citric Acid Cycle 3. Electron Transport and ATP Synthesis
Glycolysis A 6-carbon glucose molecule is broken down into two 3-carbon pyruvic acid molecules. Occurs in the cytosol. Does not need oxygen. Makes 2 net ATP molecules.
The Citric Acid Cycle Pyruvic acid loses one carbon. This 2-carbon fragment enters the citric acid cycle. NADH is made. Carbon dioxide is released. 2 ATP is made in the Citric Acid Cycle. The citric acid cycle occurs in mitochondria.
Electron Transport Chain NADH brings electrons to the electron transport chain. As electrons move from protein to protein in the electron transport chain, hydrogen ions are pumped into the intermembrane space. Hydrogen ions flow back through an ATP synthase protein. ATP synthase changes ADP to ATP. The electron transport chain makes 34 ATP. The electron transport chain occurs in mitochondria. 34
Questions 3 1. How many phosphates does ATP have? 2. What is the structure of ATP? 3. What is phosphorylation? 4. What cellular work does ATP do? 5. What is an example of mechanical work that ATP is involved in? 6. What is cellular respiration? 7. What is the overall chemical equation for cellular respiration? 8. What electron carrier does our muscles use? 9. What are the stages of cellular respiration? 10. How many ATP does glycolysis make? 11. How many ATP does the electron transport chain make? 12. Does glycolysis need oxygen? 13. Where does glycolysis occur? 14. Where do the Citric Acid Cycle and Electron Transport Chain occur?
Metabolism of Other Nutrients Carbohydrates, proteins, and fats enter cellular respiration at different stages.
Anaerobic Respiration Anaerobic respiration is when cells make energy when there is no oxygen. The more you exercise, the less oxygen your muscle cells have. As a result, your muscle cells get their ATP from glycolysis. And NAD + becomes low. Fermentation occurs to regenerate NAD +.
If fermentation happens for a long time, more lactic acid is made. Lactic acid moves to the liver, or liver cells use oxygen to convert it back to pyruvic acid. This is why you breathe heavily during exercise. Fermentation
Hitting the Wall Feel like legs turn to wood while running or biking. There's too much lactic acid in the muscles. Oxygen debt becomes too large. Muscles shut down until there is enough oxygen for proper feeling in the legs.
Do you drink beer or wine? Beer comes from grain. Wine comes from grapes. Yeast without oxygen makes ethyl alcohol. This happens in fermentation. Yeast changes sugars in grains or grapes into ethyl alcohol and carbon dioxide.
Summary of Anaerobic Respiration Ethyl alcohol = ethanol
Questions 4 1. At what stage do fats enter cellular respiration? 2. At what stage do carbohydrates enter cellular respiration? 3. At what stage do proteins enter cellular respiration? 4. What is anaerobic respiration? 5. What is made, in the muscle cells, if fermentation happens for a long time? 6. What happens to your legs if they hit the wall? 7. What product is made when yeast helps to ferment grain?
Body Weight and Health Section 4.3 Pages 81-82
BMI (Body Mass Index) Your BMI is calculated by using your height and weight. BMI is not accurate. 1 in 4 people are misdiagnosed for weight-related illness and death. The BMI tables do not distinguish between lean muscle mass and body fat. For example, an athlete with a lot of muscle will weigh more than a similar size person with a lot of fat because muscle is heavier than fat. Therefore, a person can be very fit, but be classified as overweight using this table.
Body Mass Index
Overweight and Underweight are both Unhealthy
Anorexia and Bulimia (BMI is less than 18.5) Anorexia Self-starvation 1 in 5 women and 1 in 20 men in universities are starving themselves to death. Bulimia Binge eating followed by vomiting is called bulimia. binge eating is when you eat a lot of food and then prevent it to turn into fat by vomiting.
Anorexia and Amenorrhea Anorexics that stop menstruation because they have no body fat is called amenorrhea. leptin signals the brain saying that there is not enough body fat to support a pregnancy. hormones (estrogen) which regulate menstruation are blocked and menstruation stops Amenorrhea can be permanent and cause sterility in anorexics.
Anorexia and Osteoporosis estrogen helps maintain strength and size of bones when estrogen is low in the body, anorexics can have weak bones, resulting in osteoporosis.
Obesity Rates The number of Canadians, who are obese, has risen dramatically in recent years. In 2004, 23.1% of Canadians older than 18 are obese. In Canada, children obesity has substantially increased between 1989 and 2004 with rates in boys increasing from 2% to 10% and rates among girls increasing from 2% to 9%. About 4% of the adult population is obese in Korea, and about 30% are overweight (including obese). Overweight rates will increase by a further 5% within ten years. In the United States, 1 in 3 adults are obese (33%). This is all due to junk food, fast food, and lack of exercise.
But overweight and BMI data
Remember Eat healthy and you will be fine!
Questions 5 1. How is BMI calculated? 2. What is bulimia? 3. What is anorexia? 4. What is amenorrhea? 5. What hormone signals the brain saying that there is not enough body fat to support a pregnancy? 6. What hormone regulates menstruation? 7. Can amenorrhea be permanent in anorexics? 8. Can anorexics have osteoporosis? 9. Why do anorexics have weak bones? 10. Why is BMI not accurate for weight-related illnesses and death? 11. Does obesity exist in Korea?