Chapter 2: The Chemical Level of. Organization. Copyright 2009, John Wiley & Sons, Inc.

Transcription

1 Chapter 2: Organization The Chemical Level of

2 Question Of the following functions, the major propose of RNA is to A. Function in the synthesis of protein. B. Transmit genetic information to offspring. C. Form the genes of higher organisms. D. Act as a pattern or blueprint to form DNA.

3 Question In a DNA molecule, adenine always pairs with what other nitrogenous base? a) Thymine b) Cytosine c) Guanine d) The make up of pairs varies

4 Terms to know 1. Carbohydrates 2. Lipids 3. Phospholipids 4. Steroids 5. Proteins 6. Enzymes 7. DNA 8. RNA 9. ATP

5 Presentation Preview Requirements: Title slide with your name, date, and period. Create one slide for each term Include a simple definition of the term (2-3 sentences) Include a picture that helps explain Also include the website you received the information from. Submit on Google Classroom!

6 Discussion Questions 1. Explain the function of carbohydrates. Provide several examples of them. 2. Describe polysaccharides. How does the human body use them? 3. Explain what a lipid is. Common lipids include triglycerides and phospholipids, what are these lipids and what is their function? 4. Explain what a steroid is. What are their uses in the human body? 5. What is a protein? What are they made out of? What are they used for? 6. Explain the function of enzymes. Provide examples of some and what they are used for. 7. What is DNA? What is it made up of? Where do you find it? 8. What is RNA used for? How is it different from DNA? 9. Explain what Adenosine Triphosphate (ATP) is. What is it made up of?

7 Discussion Questions 2 1. Some amateur and professional athletes take anabolic steroids to help them bulk up or build strength. The health risks of this practice are extensively documented. Apart from health considerations, how do you feel about the use of chemicals to enhance athletic performance? Do you think an athlete who takes anabolic steroids is cheating, or is the use of such chemicals just part of the preparation required to succeed in a competitive sport? Defend your answer. 2. Given the materials commonly found in a kitchen, explain how one could distinguish between a protein and a lipid. 3. A student is given two unlabeled substances, one a typical phospholipid and one a typical protein. She is asked to determine which substance is the protein and which is the phospholipid. The available technique in her lab will allow her to determine the elements in each sample. How can she identify each substance? 4. Explain why heat, ph changes, and other environmental changes can interfere with a protein s function. 5. How can a cell make many different kinds of protein out of only 20 amino acids? 6. A few human enzymes work best at a very low ph of about 2. Where in the body do you think these enzymes are located? What kind of enzymes do you think are found here? 7. Why do phospholipids tend to organize together into a bilayer in an aqueous (water based) environment? 8. Explain how each of the following food preservation methods would interfere with a microbe s enzyme activity and ability to break down food: canning (heating), freezing, pickling (soaking in acetic acid), salting. 9. A genetic mutation can change the primary structure of a protein. How can this destroy the proteins function?

8 Carbohydrates Carbohydrates provide most of the energy needed for life and include sugar. Some carbohydrates are used to build structures and to generate ATP. Others are stored. Three types: monosaccharides, disaccharides, and polysaccharides

9 Polysaccharides Polysaccharides are the largest carbohydrates and may contain hundreds of monosaccharides. The principal polysaccharide in the human body is glycogen, which is stored in the liver or in muscle. When blood sugar level drops, the liver hydrolyzes glycogen to yield glucose which is released from the liver into the blood

10 Lipids Lipids, like carbohydrates, contain carbon, hydrogen, and oxygen. Hydrophobic (do not mix with water) Triglycerides are the most plentiful lipids in the body and they provide energy. Phospholipids are important membrane components.

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12 Steroids Steroids have four rings of carbon atoms. Examples include hormones, vitamins and cholesterol. cholesterol, with cholesterol serving as an important component of cell membrane.

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14 Proteins Constructed from combinations of 20 base amino acids. dipeptides formed from 2 amino acids joined by a covalent bond (called a peptide bond). polypeptides chains can be from 10 to 2000 amino acids.

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16 Enzymes = Catalyst Catalyst - a substance that increases the rate of a chemical reaction Enzymes speed up chemical reactions.

17 DNA Deoxyribonucleic acid (DNA) forms the genetic code inside each cell and thereby regulates most of the activities that take place in our cells throughout a lifetime. The basic units of nucleic acids are nucleotides, composed of a nitrogen base, sugar, and a phosphate group.

18 RNA Structure Ribonucleic acid (RNA) relays instructions from the genes in the cell s nucleus to guide each cell s assembly of amino acids into proteins by the ribosomes. Differs from DNA single stranded ribose sugar not deoxyribose sugar Contains uracil instead of thymine

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20 Adenosine Triphosphate (ATP) Molecule that acts as the temporary molecular storage of energy

21 Review Video Review: Another Review: sy

22 Question Which type of lipid is a major component of cell membranes? a) Fatty acids b) Triglycerides c) Vitamin D d) Phospholipids

23 Question The sequence of amino acids found in a protein makes up which level of organization? a) Quaternary b) Primary c) Secondary d) Tertiary