Biology Chapter 47 Preclass PDF

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These are the answers for the chapter 47 pre class assignment, this is for professor Jiyun Kim. If you have another professor this still may help you as additional notes. Chapter 47 is on Metabolism. ...

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Why do animals require nutrients? a. To provide energy for the production of ATP within cells b. To provide a source of materials for assembly of macromolecules All the bodily activities and chemical reactions in an organism that maintain life are called a. Metabolism  The most important energy source during the absorptive state is: a. Glucose What happens to nutrients during the absorptive state? a. They enter the blood from the gastrointestinal tract. The phase in which the alimentary canal is empty of nutrients and the body's own stores must supply energy is called the what state? a. Post absorptive state Nutrients acquired by animals are used to assemble macromolecules or are used as fuel to generate energy in the form of blank that can be used to drive cellular reactions? a. ATP The metabolic rate of an organism is that rate at which the organism:

a. uses energy for bodily activities and chemical reactions  During the postabsorptive state, the consumption of glucose by cells ______, and the consumption of fatty acids by cells ______ compared to the absorptive state. a. Decreases , increases

What happens during the postabsorptive state? a. The gastrointestinal tract is empty of nutrients. b. The body's own stores supply energy.  Intestinal epithelial cells resynthesize digested lipids into ______ before they are absorbed into the blood. a. Triglycerides Carbohydrates are broken down into and then absorbed. a. Monosaccharides In fat cells, excess glucose is incorporated into ______ to be stored. a. triglycerides Cells require a constant supply of amino acids for the synthesis of . a. proteins During digestion, Blank 1are broken down into glucose and other monosaccharides, Blank 2, are broken down into amino acids, and Blank 3 are broken down into fatty acids and monoglycerides. a. Carbohydrates b. Proteinds c. Triglycerides What is NOT synthesised during the absorptive state? a. Glucose Mechanisms that help to maintain a constant blood glucose concentration in the postabsorptive state include: a. Gluconeogenesis b. Ketone production c. Glycogenolysis

d. Glucose sparing  Why do cells require a constant supply of amino acids? a. Proteins are constantly being synthesized and broken down, but excess amino acids are converted into fatty acids.  The breakdown of glycogen into glucose monomers is called: a. Glycogenolysis What is gluconeogenesis? a. The synthesis of new glucose from noncarbohydrate precursors  Glycogenolysis, lipolysis, and ketone production help to maintain blood ______ levels during the postabsorptive state. a. Glucose In the postabsorptive state, glycogen and lipids are: a. Broken down Glycogenolysis, which occurs primarily in the blank, produces blank, which is released into the blood. a. Liver b. Glucose What is lipolysis? a. The breakdown of triglycerides into fatty acids and glycerol Gluconeogenesis occurs in the and results in the production of glucose that is secreted into the . a. Liver

b. Blood  How does glucose sparing by other organs help the brain?

a. It prevents other organs from depleting the blood of glucose needed by the brain. During the postabsorptive state, the liver converts fatty acids into small compounds called blank , that provide an important energy source during prolonged fasting. a. Ketones Energy-producing molecules are maintained at homeostatic levels in the blood due to control by the and systems. a. Endocrine b. Nervous  What type of molecule is insulin? a. Hormone Which of the following processes are upregulated during the absorptive state compared to the postabsorptive state? a. Triglyceride synthesis b. Glycogen synthesis The blood concentration of insulin increases during the blank state and decreases during the state. a. Absorptive b. Post absorptive The liver breaks down fatty acids during the postabsorptive state to synthesize: a. Ketones Put the steps involved in insulin signaling in the correct order, from first (on top) to last. 1. Insulin is released by pancreas

2. Insulin binds to receptor cells and stimulates a pathway 3. GLUTS increase 4. Glucose is taken by the cell 5. Blood glucose decreases What process is stimulated by insulin? a. Glucose transport in the cell How does insulin act to affect blood glucose levels? a. It binds to a cell-surface receptor, which stimulates a pathway that increases glucose transport into the cell, thus lowering levels in the blood.  In insulin-responsive tissues like muscle and adipose tissue, when insulin is present, ______ in the cytosol that store glucose transporters fuse with the plasma membrane and make more glucose transporters available to transport glucose into the cell. a. Vesicles  Put the events that occur after a meal in the correct order, from first to last. 1. 2. 3. 4. 5.

Blood glucose level increase Pancreas secretes insulin GLUTS are inserted Cells increase uptake of glucose Blood glucose level lowers

What stimulates the secretion of glucagon?

a. Low blood glucose

Energy created or destroyed a. Cannot The ______ in ATP store energy that can be used for biological activities.

a. Chemical bonds The amount of heat required to raise the temperature of one gram of water one degree Celsius is equal to

a. 1 calorie What is the basal metabolic rate? a. The metabolic rate of an animal at rest, in the postabsorptive state, and at a standard temperature An animal that is able to generate its own internal heat through its metabolism is called a(n) . a. Endotherm The chemical bonds in ATP that store cells can use for biological activities a. Energy The amount of oxygen consumed by an animal with a high BMR will be ______ the amount of oxygen consumed by an animal with a low BMR. a. Greater than Factors that can affect an animal's metabolic rate include: a. b. c. d.

Digestion Activity Sleep Body mass

The amount of energy an animal expends per gram of body mass is its - BMR. a. Mass specific Satiety is important for: a. short-term control of feeding How do eating and digesting food affect an animal's metabolic rate? a. They increase the metabolic rate.

 Mass-specific BMR is useful because it allows scientists to compare the metabolic rates of animals that differ with respect to: a. Size In humans, long-term intake of food is controlled by emotional state, signaling molecules in the brain, and by . a. Hormones An increase in fat mass is expected to leptin secretion. a. Increase What part of the brain does leptin target? a. Hypothalamus Leptin appetite and metabolic rate. a. Decrease b. Increase Leptin is produced and secreted in proportion to: a. Fat mass Fasting blank leptin secretion a. Lowers  What are the effects of leptin? a. It increases metabolic rate. b. It decreases appetite. A hormonal blank factor is believed to explain the balance between food intake and energy balance a. Satiety

The rare cases where leptin has successfully been used to treat obesity in humans involve individuals who have a mutation in the blank gene and do not produce the active hormone. a. Leptin Fasting for a long period of time results in: a. increased appetite b. decreased BMR  What aspects of cellular structure and function are affected by temperature? a. Protein folding and function b. Rates of chemical reactions c. Plasma membrane structure  The use of leptin in humans has had limited success in reducing obesity because:

a. most obese humans produce leptin but do not respond to it Match each term with the correct definition. a. b. c. d.

Radiation - the emission of electromagnetic waves from surface of an object Evaporation Convection - transfer of heat by movement of air or fluid next to the body Conduction - where the body loses or gains heat through the direct contact with cooler or warmer substances Heat loss to the environment can be reduced by ______ blood vessels near the skin surface. a. Constricting What is the purpose of countercurrent heat exchange? a. To retain heat to warm an animal's core  

What is countercurrent heat exchange? a. The transfer of heat from warm blood to cold blood that is being returned to the body's core The production of body heat by the rapid contraction of muscles without locomotion is called thermogenesis. a. Shivering thermogenesis  Shivering thermogenesis is a result of _______, and _______ is responsible for nonshivering thermogenesis. a. skeletal muscle contraction; brown adipose tissue In thermogenesis, the metabolic rate and heat production are increased without using muscle activity. a. Nonshivering thermogenesis  Which of the following are health risks associated with excess body fat? a. Heart disease b. Cancer What measurement is used to assess body fat and health risks? a. BMI A man who is 178 cm tall has a BMI of 30. What is his approximate weight? a. 95 kg     

● Recall that the liver converts fatty acids into ketones. ● Outline the mechanisms that maintain blood glucose concentration in the postabsorptive state. ● Recall that insulin promotes the transport of glucose from extracellular fluid into cells.   

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