Frady's Biology



biospherebiodiversity species biology scienceorganism cell metabolism DNAsystemCHAPTER1BIOLOGY IN THE 21ST CENTURYVocabulary Practiceecosystemhomeostasis evolution adaptation observation data hypothesis experimentindependent variabledependent variableconstant theory microscope genemolecular genetics genomics biotechnologytransgenicA. Categorize WordsFor the terms below, write L next to words that can describeliving things. Write T next to words that can describe technology. Write B next to wordsthat can describe both.1. organism species biotechnology cell transgenic molecular geneticsFor the terms below, write E next to words that can describe the external environment ofliving things. Write I next to words that can describe the internal environment of living things. Write B next to words that can describe both.2. homeostasis system ecosystem biosphere metabolism biologyFor the terms below, write G next to words that are related to groups of living things. Write Inext to words that describe individual living things. Write B next to words that can describe both.3. biodiversity cell biosphere organism adaptation evolutionVOCABULARY PRACTICE, CONTINUEDB. Vector Vocabulary Define the words in the boxes. On the line across each arrow,write a phrase that describes how the words in the boxes are related to each other.2. 3 .6. 8. 9. 10. 14. DATA15. CONSTANT1 3 . DEPENDANT VARIABLE12. INDEPENDENT VARIABLE11. EXPERIMENT7. HYPOTHESIS5. THEORY4. OBSERVATION1. VOCABULARY PRACTICE, CONTINUEDC. Stepped-Out Vocabularythat are related to the word.Define each word. Then write two additional factsWORDDEFINITIONMORE INFORMATIONExample metabolismall chemical processes that build up or break down materials in living thingschemical energy is neededanimals eat other organisms to get their chemical energy1. biology2. microscope3. evolution4. adaptation5. DNA6. gene7. genomics12. If I form a hypothesis, do I propose an answer to a question or do I use negativefeedback?11. Does a transgenic organism travel a lot or does it have genes from a different type ofliving thing?10. Which is a species, a group of parts that interact to form a whole or a type of livingthings that can reproduce by interbreeding?9. Where would more biodiversity be found, near Earth’s equator or near Earth’s poles?8. When I am in an ecosystem, do I interact with living things, nonliving things, or bothliving and nonliving things?7. Does a theory answer one scientific question or does it explain many observations?6. Would a constant be manipulated or kept the same in an experiment?5. Is an adaptation in biology made by choice or is it inherited?4. Is a gene all of an organism’s DNA or only a segment of DNA?3. Which is the independent variable in an experiment, the cause or the effect?2. Is homeostasis the maintenance of constant conditions or all of the chemical processesthat build up and break down materials?D. Words in Context Answer the questions to show your understanding of thevocabulary words.1. If I use a microscope, do I see things too small to be seen or things too far away to be seen?VOCABULARY PRACTICE, CONTINUEDEnzyme ActionPre-AP ActivityIn Chapter 2, you have learned about carbon–based molecules, chemical reactions, enzymes and the relationships between them. Enzymes are necessary for every process in an organism. More specifically, enzymes are an integral part of the digestive system, where they act as catalysts to break down carbon–based molecules through a series of chemical reactions.CARBON–BASED MOLECULESCarbohydrates, lipids, and proteins are three examples of carbon–based molecules that can be broken down through enzymatic action.?Carbohydrates, including sugars and starches, are used by the body for energy. Sugars can be classified as monosaccharides, disaccharides, or polysaccharides. Monosaccharides are simple sugars, disaccharides are molecules of two simple sugars bonded together, and polysaccharides are polymers made of monosaccharides. Starches, glycogen, and cellulose are all examples of polysaccharides.?Lipids are needed for energy, to supply structural components of cell membranes and myelin sheaths, and for the production of some hormones. The most common type of lipids are fats and oils. Fats and oils are made of a glycerol molecule bonded to a fatty acid molecule. When three fatty acids are bonded to a glycerol, they form a triglyceride. Fatty acids that are joined by carbon-to-carbon single bonds are known as saturated fats and those joined by at least one carbon-to-carbon double bond are unsaturated fats.?Proteins, the raw materials needed for cell and tissue repair and growth, are polymers made of monomers called amino acids. Amino acids are bonded together by a specific type of covalent bond, a peptide bond. When a chain of amino acids bond together, they form a polypeptide. A protein is made of one or more polypeptides. Most enzymes are proteins.DIGESTION AND ENZYMESMost carbon–based molecules do not provide any nutritional benefit until they are broken down into simpler substances through digestion. In the human body, the majority of digestion takes place in three locations: the mouth, the stomach, and the small intestine. Digestion begins in the mouth and finishes in the small intestine. The pancreas also plays an important role in digestion. Pancreatic secretions aid digestion in the small intestine. Enzymes released in the mouth, stomach, and small intestine facilitate the digestion of specific carbon–based molecules by breaking them down into simpler substances.Most enzymes are sensitive to their environment and require specific conditions to function optimally. One such condition is pH, which is a measure of how acidic something is. The optimal pH value for most enzymes is between 6 and 8. Enzymatic action can decrease if the pH becomes more acidic or more basic.Pre-AP Activity continuedHuman Digestive OrganEnzymeFunctionMouth(pH 7.0)Salivary amylaseBreaks starches (polysaccharides) down into disaccharides and trisaccharidesLingual lipaseBreaks triglycerides (fats and oils) and other lipids into fatty acids and diglyceridesStomach (pH 1–3)PepsinBreaks proteins down into peptidesGastric lipaseBreaks short–chain triglycerides (fats and oils) in fat molecules in milk into fatty acids and monoglyceridesPancreas (secretes enzymes into the stomach)Pancreatic amylaseBreaks starches (polysaccharides) into maltose (disaccharide) and maltotriose (trisaccharide)TrypsinBreaks proteins into peptidesPancreatic lipaseBreaks emulsified triglycerides (fats and oils) into fatty acids and monoglyceridesSmall Intestine (pH 6–6.5)MaltaseBreaks maltose into glucoseSucraseBreaks sucrose into glucose and fructoseLactaseBreaks lactose into glucose and galactoseDipeptidaseBreaks dipeptides into amino acidsAnswer the following questions on a separate piece of paper.1.What inferences can you make regarding the pH of a particular part of the digestive system and the type and relative size of the carbon–based molecules that are broken down there?2.If the optimal pH range of most enzymes is between 6 and 8, is there possibly some advantage to having certain enzymes, such as pepsin, active in the low pH of the stomach?3.The stomach is a relatively small muscular organ compared to the small intestine that can be a long as six meters. Yet food tends to be held in the stomach and released in only small amounts into the small intestine. What does that suggest to you about where nutrients are absorbed? How do the products of enzyme action described in the table support your thinking?ACTIVE READING WORKSHEETSCELL STRUCTURE AND FUNCTIONCell Organelles and FeaturesRead the passage below, which covers topics from your textbook. Answer the questions that follow.Most of the functions of a eukaryotic cell are controlled by the nucleus. The nucleus is filled with a jellylike liquid called the nucleoplasm, which holds the contents of the nucleus and is similar in function to a cell’s cytoplasm. The nucleus houses and protects the cell’s genetic information. The hereditary information that contains the instructions for the structure and function of the organism is coded in the organism’s DNA, which is contained in the nucleus. When a cell is not dividing, the DNA exists in the form of long, thin structures called chromatin. When a cell is about to divide, the DNA condenses to form chromosomes. Chromosomes are structures in the nucleus made of DNA and protein.The nucleus is surrounded by a double membrane called the nuclear envelope. The nuclear envelope is made up of two phospholipids bilayers. Covering the surface of the nuclear envelope are tiny, protein-lined holes, which are called nuclear pores. The nuclear pores provide passageways for materials to enter and leave the nucleus.Read the question and write your answer in the space provided.SKILL: Recognizing Similarities and Differences1.How is a nuclear envelope similar to a cell membrane?Read the question and write your answer in the space provided.SKILL: Vocabulary Development2.The term nucleus is derived from a Latin word meaning “kernel” or “nut.” How is the term nucleus related to its Latin term of origin?Circle the letter of the word or phrase that best completes the sentence.3.The nucleus is filled with a jellylike liquid called thea.nuclear pore.c.chromatin.b.nuclear envelope.d.nucleoplasm.ACTIVE READING WORKSHEETSHOMEOSTASIS AND CELL TRANSPORTPassive TransportRead the passage below, which covers topics from your textbook. Answer the questions that follow.One type of passive transport is called facilitated diffusion. This process is used for molecules that cannot readily diffuse through cell membranes, even when there is a concentration gradient across the membrane. Such molecules may not be soluble in lipids, or they may be too large to pass through the pores in the membrane. In facilitated diffusion, the movement of these kinds of molecules across the cell membrane is assisted by specific proteins in the membrane. These proteins are known as carrier proteins.In facilitated diffusion, a carrier protein binds to a specific molecule it transports. As soon as the molecule binds to the carrier protein, the carrier protein changes shape. This altered shape may shield the molecule from the hydrophobic interior of the lipid bilayer. Once shielded, the molecule can be transported across the cell membrane. On the other side of the membrane, the molecule is released from the carrier protein, which then returns to its original shape.Read each question and write your answer in the space provided.SKILL: Sequencing Information1.Order the statements to show the steps of facilitated diffusion. Write “1” on the line in front of the statement that describes what happens first. Write “2” on the line in front of the statement that describes what happens next, and so on.a.The molecule is released from the carrier protein.b.The carrier protein changes shape.c.The molecule is transported across the cell membrane.d.The molecule binds to a carrier protein.e.The carrier protein returns to its original shape.f.The molecule is shielded from the hydrophobic interior of the lipid bilayer.2.In order of occurrence, briefly describe what happens in each of the three main parts of facilitated diffusion.a.b.c. Write your answer in the space provided.SKILL: Vocabulary Development3.The term diffusion comes from a Latin word meaning “to spread apart.” How is the term diffusion related to its Latin word of origin?Circle the letter of the phrase that best answers the question.4.What types of molecules diffuse through the cell membrane by facilitated diffusion?a.molecules that are not soluble in lipidsb.molecules that are too large to pass through pores in the membranec.molecules that can survive the hydrophobic interior of the lipid bilayerd.both (a) and (b) ................
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