Monday, November 26, 2007
Mon-Day 1
Bio- for HW that is due on Wednesday:
1. Outline text section 9.1
2. Write test corrections with correct and complete EXPLANATIONS of each question/answer that you got wrong.
We introduced our new unit: Cell Respiration and Photosynthesis. We will first focus on cellular respiration and then we will cover photosynthesis; we will then analyze the differences, similarities, and inter-relationships between these two vital cellular processes.
We discussed an organism's need for energy for many of its metabolic activities: active transport, muscle contractions, nerve impulses, and dehydration synthesis reactions. This energy must be derived from nutrients such as carbohydrates, which are broken down to glucose via digestive enzymes in the saliva and intestinal juices. The energy stored in the bonds of glucose is transferred to the energy stored in the bonds of ATP via cellular respiration. Whenever a cell needs energy for any metabolic process, ATP is then hydrolyzed and energy is released from the ATP molecule and is used to drive/power the metabolic process.
We noted that if energy were derived from glucose all at once, too much energy would be released and, perhaps, enzymes would then denature. Because the energy that is stored in the bonds in glucose is GRADUALLY transferred via a large series of chemical reactions/steps to the energy stored in the bonds in ATP, there is a controlled release of energy that is sufficient to meet the energy requirements of normal metabolic processes. The energy released per molecule of ATP that is hydrolyzed is not so overwhelming as to denature any proteins or heat up the cytoplasm.
Chem 7- we revisited the earlier models of the atom, the Dalton hard-neutral-sphere model and the Thomson plum pudding model. We deduced how the Laws of Constant Composition and Multiple Proportions led Dalton to his model of indivisible atoms that combine in definite, whole-number ratios. We reviewed how Thomson proposed his model of the atom based on the beam of negatively charged particles that he forced out of silver atoms in the cathode-ray tube.
We then focused on the brilliant Rutherford Gold Foil experiment which ultimately disproved Thomson's "positive diffuse jelly" component of the atom. For 1/10000 of the positively charged alpha particle to be deflected practically straight back from the foil showed that each atom has a very tiny (1/10000 the volume of the whole atom), dense/massive, positively charged nucleus. If atoms were really made of a diffuse, positive jelly, ALL of the positively charged alpha particles would have passed through the foil of gold atoms with practically no deflection.
We will discuss the next development to a more precise and accurate (Bohr) model of the atom.
Chem 8/9- we revisited the earlier models of the atom, the Dalton hard-neutral-sphere model and the Thomson plum pudding model. We deduced how the Laws of Constant Composition and Multiple Proportions led Dalton to his model of indivisible atoms that combine in definite, whole-number ratios. We reviewed how Thomson proposed his model of the atom based on the beam of negatively charged particles that he forced out of silver atoms in the cathode-ray tube.
We then focused on the brilliant Rutherford Gold Foil experiment which ultimately disproved Thomson's "positive diffuse jelly" component of the atom. For 1/10000 of the positively charged alpha particle to be deflected practically straight back from the foil showed that each atom has a very tiny (1/10000 the volume of the whole atom), dense/massive, positively charged nucleus. If atoms were really made of a diffuse, positive jelly, ALL of the positively charged alpha particles would have passed through the foil of gold atoms with practically no deflection.
We will discuss the next development to a more precise and accurate (Bohr) model of the atom.
We finished our "Atomic Mass" lab. Some are still not applying the significant figures rules properly; though sig figs are not the most important things in the world, the rules are very brief and they are never going to change. Learn them for yourself now and you won't have a problem with them again- there are many websites for practice with sig figs and the text also has examples but nothing is going to beat the Atlantic-Pacific rule/mnemonic that we did in class; also, the examples that we did regarding the addition/subtraction vs. multiplication/division rules were thorough and perfectly representative of ANY sig figs problem. Check them out.
1. Outline text section 9.1
2. Write test corrections with correct and complete EXPLANATIONS of each question/answer that you got wrong.
We introduced our new unit: Cell Respiration and Photosynthesis. We will first focus on cellular respiration and then we will cover photosynthesis; we will then analyze the differences, similarities, and inter-relationships between these two vital cellular processes.
We discussed an organism's need for energy for many of its metabolic activities: active transport, muscle contractions, nerve impulses, and dehydration synthesis reactions. This energy must be derived from nutrients such as carbohydrates, which are broken down to glucose via digestive enzymes in the saliva and intestinal juices. The energy stored in the bonds of glucose is transferred to the energy stored in the bonds of ATP via cellular respiration. Whenever a cell needs energy for any metabolic process, ATP is then hydrolyzed and energy is released from the ATP molecule and is used to drive/power the metabolic process.
We noted that if energy were derived from glucose all at once, too much energy would be released and, perhaps, enzymes would then denature. Because the energy that is stored in the bonds in glucose is GRADUALLY transferred via a large series of chemical reactions/steps to the energy stored in the bonds in ATP, there is a controlled release of energy that is sufficient to meet the energy requirements of normal metabolic processes. The energy released per molecule of ATP that is hydrolyzed is not so overwhelming as to denature any proteins or heat up the cytoplasm.
Chem 7- we revisited the earlier models of the atom, the Dalton hard-neutral-sphere model and the Thomson plum pudding model. We deduced how the Laws of Constant Composition and Multiple Proportions led Dalton to his model of indivisible atoms that combine in definite, whole-number ratios. We reviewed how Thomson proposed his model of the atom based on the beam of negatively charged particles that he forced out of silver atoms in the cathode-ray tube.
We then focused on the brilliant Rutherford Gold Foil experiment which ultimately disproved Thomson's "positive diffuse jelly" component of the atom. For 1/10000 of the positively charged alpha particle to be deflected practically straight back from the foil showed that each atom has a very tiny (1/10000 the volume of the whole atom), dense/massive, positively charged nucleus. If atoms were really made of a diffuse, positive jelly, ALL of the positively charged alpha particles would have passed through the foil of gold atoms with practically no deflection.
We will discuss the next development to a more precise and accurate (Bohr) model of the atom.
Chem 8/9- we revisited the earlier models of the atom, the Dalton hard-neutral-sphere model and the Thomson plum pudding model. We deduced how the Laws of Constant Composition and Multiple Proportions led Dalton to his model of indivisible atoms that combine in definite, whole-number ratios. We reviewed how Thomson proposed his model of the atom based on the beam of negatively charged particles that he forced out of silver atoms in the cathode-ray tube.
We then focused on the brilliant Rutherford Gold Foil experiment which ultimately disproved Thomson's "positive diffuse jelly" component of the atom. For 1/10000 of the positively charged alpha particle to be deflected practically straight back from the foil showed that each atom has a very tiny (1/10000 the volume of the whole atom), dense/massive, positively charged nucleus. If atoms were really made of a diffuse, positive jelly, ALL of the positively charged alpha particles would have passed through the foil of gold atoms with practically no deflection.
We will discuss the next development to a more precise and accurate (Bohr) model of the atom.
We finished our "Atomic Mass" lab. Some are still not applying the significant figures rules properly; though sig figs are not the most important things in the world, the rules are very brief and they are never going to change. Learn them for yourself now and you won't have a problem with them again- there are many websites for practice with sig figs and the text also has examples but nothing is going to beat the Atlantic-Pacific rule/mnemonic that we did in class; also, the examples that we did regarding the addition/subtraction vs. multiplication/division rules were thorough and perfectly representative of ANY sig figs problem. Check them out.
# posted by C @ 7:35 AM 
