BIO 140 EXAM 2 fully solved and updated

Organelles - answer-- Within a cell, a structure that has a particular function - They carry out activities within the cell Cytoplasm - answer-The gel like matrix inside cells but outside of cell organelles Extracellular - answer-Situated outside of a cell Intracellular - answer-Situated within a cell Cell membrane - answer-- Provides boundary between the extracellular and the intracellular - Regulates movement of substances into and out of cells Transport across cell membranes - answer-- Cell membranes allow some substances to cross them more readily than others - Nutrients and other substances outside of cell can be transported across cell membranes through passive and active transport Passive transport - answer-A non - energy [ATP] requiring mechanism whereby a substance moves from a region of higher concentration to that of a lower concentration Types of passive transport mechanisms - answer-- Simple diffusion - Facilitated diffusion - Osmosis Facilitated diffusion - answer-A passive transport mechanism whereby a substance crosses a cell membrane with the assistance of a transport protein - Energy is required - Substance moves from high concentration to low concentration Electrolytes - answer-Substances such as salt that dissolve or dissociate into ions when put in water Solutes - answer-A substance that dissolves in a solvent Solution - answer-A mixture of two or more substances that are uniformly dispersed - Example: dissolving salt in water creates saline Active transport - answer-An energy [ATP] requiring mechanism by which some substances cross cell membranes Mitochondria - answer-Cellular organelles involved in generating energy [ATP] Nucleus - answer-A membrane enclosed organelle that contains the genetic material DNA Organ systems work together to maintain homeostasis - answer-- The ability of organ systems to work together to carry out common functions requires constant communication Two well-developed communication systems that coordinate physiological processes - answer-- the nervous systems - the endocrine systems The nervous systems - answer-Receives and transmits information via electrical impulses between nerve cells The endocrine systems - answer-Receives and transmits information via chemical messengers, called hormones, in the blood Hormones - answer-a regulatory substance produced in an organism and transported in tissue fluids such as blood or sap to stimulate specific cells or tissues into action. Homeostasis - answer-- The nervous and endocrine systems continuously monitor our internal environment, responding to change and restoring balance - Allow humans and other organisms to adapt in an ever-changing environment Negative feedback systems - answer-Play a vital role in homeostasis by opposing changes in the internal environment and by initiating corrective responses that restore balance Negative feedback systems example - answer-- Regulation of blood glucose - In response to a carbohydrate rich meal, blood glucose level rise [change in the internal environment] - The pancreas detects this change and initiates the release of the hormone insulin - As a result, blood glucose levels are restored How does the digestive system break down food to its nutrient components? - answer-- To nourish you body, your digestive system methodically disassembles the complex molecules in food into simpler basic nutrient components - This task requires many organ systems, but primarily it is the digestive system that gets the job done What is the digestive system made up of? - answer-- the Digestive tract - Accessory organs Digestive tract or the Gastrointestinal [GI] tract - answer-A tubular passage that runs from the mouth to the anus that includes several organs that participate in the process of digestion - Organs that makeup the G.I.: -- mouth -- esophagus -- Stomach -- Small intestine -- Large intestine Accessory organs - answer-Release secretions needed for the process of digestion into ducts, which empty into the lumen - Organs that makeup accessory organs: -- salivary glands -- pancreas -- biliary system, which are the liver and the gallbladder Lumen - answer-The inner cavity inside a tubular structure in the body that spans the entire length of the GI tract What three functions do the GI tract and accessory organs carry out? - answer-- Digestion - Absorption - Egestion Digestion - answer-The physical and chemical breakdown of food by the digestive system into a form that allows nutrients to be absorbed Absorption - answer-The passage of nutrients through the lining of the GI tract into the blood or lymphatic circulation Egestion - answer-The process whereby solid waste [feces] is formed and expelled from the body Elimination - answer-Elimination of waste from cells not the body - Elimination of nonabsorbed materials via feces. - Elimination of metabolic waste products via urine, breath [gases] and sweat. - Kidneys play an especially important role [production of urine] Gallbladder - answer-- Storage reservoir for bile - Dispersion of large fat globules - Gallstones: -- Cause -- Risk factor - Bules breaks down fat so that enzymes can act on it Gallbladder function - answer-Stores and releases bile made by the liver - Bile is needed for lipid digestion Bile - answer-A fluid, made by the liver and stored and released from the gallbladder, that contains bile salts, cholesterol, water, and bile pigments - Needed for fat digestion Pancreas - answer-Releases pancreatic juices that neutralize chyme and contains enzymes needed for carbohydrates, protein, and lipid digestion Digestive Juices: Gastrointestinal [GI] secretions aid digestion and protect the GI tract - answer-The organs that make up the digestive system release a variety of GI secretions that are important for digestion and the protection of the GI tract - water - acid - electrolytes - mucus - salts - enzymes - bile - bicarbonate Mucus - answer-Forms a protective coating that lubricates the mucosal lining GI secretions - answer-Substances released by organs that make up the digestive system that facilitate the process of digestion; also called digestive juices - The mucosa produces a variety of GI secretions such as enzymes and hormones that facilitate the chemical breakdown of food in the GI tract Process of gallbladder - answer-- Once bile is made by the liver, some of it is transported to the gallbladder where it can be stored for later release - When the gallbladder contracts, bile is released into the cystic duct -- The cystic duct joins the common bile duct Digestive enzymes - answer-Biological catalysts that facilitate chemical reactions that break chemical bonds by the addition of water [hydrolysis], resulting in the breakdown of large molecules into smaller components Types of Digestive enzymes - answer-- Pancreatic enzymes - Intestinal enzymes Pancreatic enzymes - answer-Produced in the pancreas released into duodenum Intestinal enzymes - answer-Made in intestinal epithelial cells also released into duodenum What do Digestive enzymes do? - answer-They catalyze hydrolytic [hydrolysis] chemical reactions that break chemical bonds by the addition of water - As a result, nutrient such as starch and protein are broken down into smaller, simpler components What organs release GI secretions? - answer-- Salivary glands - Stomach - Pancreas - Gallbladder - Small intestine - Large intestine GI hormones - answer-Hormones secreted by the mucosal lining of the GI tract that regulate GI motility and secretion - They are released into the blood in response to chemical and physical changes in the GI tract, and communicate with other organs GI hormones communicate with other organs - answer-- Organs can be alerted to the impending arrival of food - Influence transit time and the release of GI secretions - Communicate with appetite centers in the brain influencing the desire to eat Anatomy of GIT - answer-- Segmentation - Peristalsis Segmentation - answer-A muscular movement in the GI tract that moves the contents back and forth within a small region - Segmentation both mixes and slowly moves food through the GI tract - The circular muscles contract and relax, creating a "chopping" motion Process of Segmentation - answer-- Circular muscles alternate contracting and relaxing, which creates segments along the intestine - Chyme is pushed back and forth within adjacent segments of the intestine Peristalsis - answer-Waves of muscular contractions that move materials in the GI tract in a forward direction - Consists of series of wavelike rhythmic contractions and relaxation involving both the circular and longitude muscles - Propels food forward through the GI tract Process of Peristalsis - answer-- Circular muscles contract - Bolus of food - Longitudinal muscles relax - Circular muscles relax - Longitudinal muscles contract Food movement - answer-- Mouth - Swallowing - Stomach What happens in your mouth? - answer-- Mastication - Secretion of saliva - Taste buds - Olfactory [smell] cells Mastication - answer-Chewing and grinding of food by the teeth to prepare for swallowing Secretion of saliva - answer-- Assists with swallowing and taste sensation - Produces as you put food in mouth - Sour and acidic foods produce more saliva Taste buds [5 tastes] - answer-- Salty - Sour - Sweet - Bitter - Umami Umami - answer-A taste, in addition to the four basic taste components, that imparts a savory or meat like taste Olfactory [smell] cells - answer-- 80% of smell is connected to taste buds Swallowing - answer-Moves bolus of food from mouth to pharynx and then to the esophagus - The epiglottis opens when the food moves down but then closes Bolus - answer-A soft round mass of chewed food - As you prepare to swallow, your tongue directs the bolus toward the back of your mouth Pharynx - answer-Region toward the back of the mouth that is the shared space between the oral and nasal cavity - Before food reaches pharynx, swallowing is voluntary - After food reaches pharynx, swallowing becomes involuntary Esophagus - answer-The passageway that begins at the pharynx and ends at the stomach - Food is ready to enter after reaching pharynx Epiglottis - answer-A cartilage flap that covers the trachea while swallowing - During the involuntary phase of swallowing, the upper, back portion of your mouth rises, blocking the entrance to the nasal cavity - Helps bolus into the correct passageway Dysphagia - answer-Difficulty swallowing resulting from an injury or disease - Can make it difficult for someone to obtain adequate nourishment Gastroesophageal sphincter - answer-A circular muscle that regulates the flow of food between the esophagus and the stomach; also called the lower esophageal sphincter or cardiac sphincter - To prevent the contents of the stomach from re-entering the esophagus, the Gastroesophageal sphincter remains closed Stomach composed of three regions - answer-- the fundus - the body - the antrum The fundus - answer-Is the top portion of the stomach that extends upward, above the esophagus The body - answer-The middle portion of the stomach The antrum - answer-The lower portion of the stomach that connects to the small intestine Aspects of stomach - answer-- Pyloric sphincter - Chyme Pyloric sphincter - answer-A circular muscle that regulates the flow of food between the stomach and the duodenum [the first portion of the small intestine] Functions of stomach - answer-- Temporary storage of food - Production of gastric secretions needed for digestion - Mixing of food with gastric secretions - Physical and chemical digestion Chyme - answer-The thick fluid resulting from mixing of food with gastric secretions in the stomach - By the time food leaves stomach, the bolus is transformed into chyme Gastric mucosal barrier - answer-A thick layer of mucus that protects mucosal lining of the stomach from the acidic gastric juice Disease associated with digestion - answer-- Celiac disease - Ulcer - GERD Ulcer - answer-Can occur when gastric juice erodes areas of the mucosal lining in the esophagus, stomach, or duodenum - Gastric ulcer - Peptic ulcer Gastric ulcer - answer-An open sore in the lining of the stomach Peptic ulcer - answer-An irritation or erosion of the mucosal lining in the stomach, duodenum, or esophagus GERD - answer-A condition caused by the weakening of the gastroesophgeal sphincter, which enables gastric juices to relax into esophagus, causing irritation into the mucosal lining - Risk factor for esophageal cancer Primary cause of GERD - answer-The relaxation of the gastroesophageal sphincter, which enables the stomach contents [chyme] to move from the stomach back into the esophagus, or what is referred to as reflux Three regions that makeup the small intestine - answer-- Duodenum - Jejunum - Ileum Duodenum - answer-The first segment of the small intestine Jejunum - answer-The midsection of the small intestine, located between the duodenum and the ileum Ileum - answer-The last segment of the small intestine that comes after the jejunum Plica circulares - answer-The numerous folds of the mucous membrane of the small intestine Villi - answer-Small, finger like projections that cover the inner surface of the small intestine Enterocytes - answer-Epithelial cells that make up the lumenal surface of each vilus Microvilli - answer-Hairlike projections on the surface of enterocytes Brush border - answer-The absorptive surface of the small intestine made up of thousands of microvilli that line enterocytes Lacteal - answer-A network of blood capillaries and a lymph-containing lymphatic vessel called a lacteal, both of which circulate absorbed nutrients away from the small intestine Lactose intolerance - answer-Inability to digest the milk sugar lactose, caused by a lack of the enzyme lactase Lactose intolerance signs and symptoms - answer-Abdominal cramping, bloating, flatulence, diarrhea - Bacteria in the large intestine break down [ferment] the lactose, producing several by-products, including gas High incidence of Lactose intolerance - answer-- Asian Americans - Native Americans - African Americans Is it nature or nurture? How to deal with Lactose intolerance - answer-- Most people with lactose intolerance can consume small amounts of dairy products - Yogurt & cheese are more easily tolerated - Reduced-lactose products - Over-the-counter lactase enzymes available - Calcium supplements often needed Glycemic response - answer-The change in blood glucose following the ingestion of a specific food Glycemic index [GI] - answer-A rating system used to categorize foods according to their relative glycemic responses Glycemic load [GL] - answer-A rating system used to categorize foods that takes into account the glycemic index as well as the amount of carbohydrate typically found in a single serving of the food Glycemic load = [glycemic index / 100 x number of grams of carbohydrates] Nutrient Absorption - answer-Nutrient absorption occurs by many mechanisms, but remember that for nutrients to be absorbed they have to pass into and then out of enterocytes Circulation of nutrients in the Body - answer-Following small intestinal absorption, nutrients enter the circulation via: - Blood system which goes directly to the liver - Lymphatic system and eventually get put in the blood Bioavailability - answer-The extent to which nutrients are absorbed into the blood or lymphatic system What is Bioavailability influenced by? - answer-- Physiological conditions [Ex. iron deficiency increases iron absorption] - Other dietary components [Ex. phytates in foods decrease iron absorption] - Medication [Ex. antibiotics can impact health of small intestine] - Disease states [Ex. celiac disease disrupts iron absorption] Celiac disease - answer-An autoimmune response to the protein gluten that damages the absorptive surface of the small intestine - Protein found in cereal grains - Antibodies attack microvilli that can then NOT facilitate digestion and absorption as well. - Managed by gluten-free diet Probiotics - answer-Contains live bacterial cultures the increase population of specific strains of nonpathogenic bacteria in colon - Ex. Cultured dairy products Prebiotics - answer-Food that stimulates the growth of bacteria that naturally reside in the large intestine - Ex. Dietary fiber Classification of carbohydrates and composition - answer-- Simple carbohydrates - Complex carbohydrates Simple carbohydrates - answer-Sugars - Category of carbohydrates consisting of mono or disaccharides Monosaccharide - answer-Carbohydrates consisting of a single sugar - Hexoses - Glucose - Fructose Disaccharide - answer-Carbohydrates consisting of two Monosaccharides bonded together Complex carbohydrates - answer-Category of carbohydrate that includes oligosaccharides and polysaccharide Oligosaccharides - answer-Carbohydrates made of relatively few [3 to 10] Monosaccharides Polysaccharides - answer-Complex carbohydrates made up of many Monosaccharides Examples of Polysaccharides - answer-- Starch - Glycogen - Dietary fiber Stevia - answer-An herb derived from sunflowers that grow freely in tropical regions of Central and South America - Calorie free and is considerably sweeter than table sugar - FDA does not object stevia , product development by several large food manufactures are underway Photosynthesis - answer-Process whereby plants trap energy from the sun to produce glucose and oxygen from carbon dioxide and water - We consume plants with glucose, and it gives us a source of energy Fiber - answer-Polysaccharides found in plants that is not digestive or absorbed in the human small intestine Fiber types - answer-- Dietary fiber - Functional fiber - Total fiber Dietary fiber - answer-Fiber that naturally occurs in plants - Found in: -- Whole grains -- Legumes -- Vegetables -- Fruits Two categories of dietary fiber - answer-- Soluble dietary fiber - Insoluble dietary fiber Soluble dietary fiber - answer-Dietary fiber that is capable of being dissolved in water Insoluble dietary fiber - answer-Dietary fiber that is incapable of being dissolved in water Functional fiber - answer-Fiber that is added to food to provide beneficial physiological effects - Drived from natural fibrous plant sources and used to manufacture foods or other types of products Total fiber - answer-The combination of dietary fiber and functional fiber Salivary amylase - answer-Enzyme released from the salivary glands that digests starch by hydrolyzing glycosidic bonds - The chemical digestion of starch begins in the mouth when the salivary glands release the enzyme salivary amylase Fructose - answer-A six carbon monosaccharide found in honey, fruits and vegetables High fructose corn syrup - answer-A syrup manufactured from corn starch that consists of glucose and fructose and used mainly to sweeten processed food and beverages Lactose - answer-Disaccharide consisting of glucose and galactose; produced by mammary glands Maltose - answer-Disaccharide consisting of two glucose molecules bonded together; forming during the chemical breakdown of starch Sucrose - answer-Disaccharide consisting of glucose and fructose; founded primarily in fruits and vegetables Metabolic diseases associated with carbohydrate digestion - answer-- Diverticular disease - Irritable bowel syndrome Diverticular disease - answer-Condition in the large intestine; characterized by the presence of pouches that form along the intestinal wall Causes of Diverticular disease - answer-- Lodging of hard, dry feces in large intestine - This increases risk of infection and inflammation in the large intestine What does Diverticular disease result in? - answer-Protruding pouches in large intestine called diverticula: - Diverticulosis - Diverticultitis Diverticulosis - answer-Presence of diverticula Diverticultitis - answer-Inflamed diverticula Prevention of Diverticular disease - answer-- Diet high in fiber - Plenty of fluids - Exercise - Common in adults consuming Inadequate amounts of fiber-rich diets. Bran - answer-The outer layer of a grain that contains most of the fiber Germ - answer-The portion of a grain that contained most of the vitamins and minerals Endosperm - answer-The portion of a grain that contains mostly starch Irritable bowel syndrome [IBS] - answer-A condition that typically affects the lower GI tract, causing abdominal pain, muscle spasms, diarrhea, and constipation Irritable bowel syndrome [IBS] cause - answer-- While emotional stress itself is not the cause of IBS, it can be a contributing factor - IBS may occur when the colon overreacts to stimuli causing it to spasm Inflammatory bowel disease [IBD] - answer-Chronic conditions such as ulcerative colitis and Crohn's disease that cause inflammation of the lower GI tract Hypoglycemia - answer-Abnormally low level of glucose in the blood Reactive Hypoglycemia - answer-Low blood glucose that occurs when the pancreas releases too much insulin after eating carbohydrates Fasting Hypoglycemia - answer-Low blood glucose that occurs when the pancreas releases excess insulin regardless of food intake Acceptable Macronutrient Distribution Range (AMDR) [Dietary Reference Intakes for Carbohydrates] - answer-45-65% of total energy from carbohydrates Recommended Dietary Allowances (RDA) [Dietary Reference Intakes for Carbohydrates] - answer-130 g/day for adults Dietary fiber Adequate Intake (AI) [Dietary Reference Intakes for Carbohydrates] - answer-20-38 g/day Tolerable Upper Level (UL) [Dietary Reference Intakes for Carbohydrates] - answer-No Tolerable Upper Level (UL) Added sugars [Dietary Reference Intakes for Carbohydrates] - answer- 25% of total kcal Diabetes mellitus - answer-Medical condition characterized by lack of insulin or impaired insulin utilization that results in elevated blood glucose levels [hyperglycemia] Type 1 diabetes - answer-- Previously known as juvenile diabetes or insulin-dependent diabetes - Results when the pancreas is no longer able to produce insulin due to loss of insulin-producing β-cells of the pancreas Cause of types 1 diabetes - answer-- Lack of insulin production - Antibodies destroy insulin-producing β-cells of the pancreas - Autoimmune disease with genetic and environmental factors Metabolic Disturbances From Type 1 Diabetes - answer-Cells are unable to take up glucose: - So, the body thinks it's starving - When the body has to use fat and protein without glucose, it produces "ketones" -- Body can use ketones in "emergency situations" for ATP. -- BUT, high levels of ketones are toxic Other symptoms of type 1 diabetes - answer-- Extreme thirst, hunger, frequent urination - Rapid weight loss - Fatigue [cells starved for energy] Type 1 Diabetes Requires Insulin Injections - answer-- Multiple injections required daily - Pumps make diabetes easier to manage Blood Glucose Management - answer-To know how much insulin to administer, a glucometer is used to measure blood glucose levels Type 1 Diabetes: Serious Health Complications - answer-- Increased risk of heart attack or stroke - Blindness, limb amputation, impaired kidney function, loss of feeling in feet and hands Type 2 diabetes - answer-- Previously known as adult-onset or non-insulin-dependent diabetes - Results when insulin-requiring cells have difficulty responding to insulin Diabetes type 2 statistics - answer-Most common form of diabetes: - 90-95% of all cases Widespread in US: - 800,000 new cases per year - 16% age 19 or less - ADA: All adults 45 should be screened - Screen those with risk factors earlier Cause of Type 2 Diabetes - answer-- Insulin Resistance: -- Cells can't respond to insulin even when it's being produced by the pancreas -- Normal or elevated levels of insulin in blood - Symptoms result when blood glucose levels remain elevated over time Process of type 2 diabetes [1] - answer-- The pancreas releases insulin in response to an increase in blood glucose Process of type 2 diabetes [2-3] - answer-- Insulin receptors have difficulty binding insulin -- As a result, fewer glucose transporters relocate to the cell membrane, making it difficult for glucose to move from outside the cell to the inside of the cell - Glucose accumulates in the blood, resulting in hyperglycemia Genetics and Lifestyle Increase Risk of Type 2 Diabetes - answer-Genetics and ethnicity: - Caucasians: 7% - African Americans: 11% - Pima Indians: Highest rate in US Other major factors: - Obesity Nutritional environment in utero and in infancy Obesity and Type 2 Diabetes - answer-- 80% of people with type 2 diabetes are overweight: -- Abdominal body fat -- Hormones secreted by adipose tissue - Incidence of type 2 diabetes parallels obesity incidence Birth Weight and Type 2 Diabetes - answer-- Both low and high birth weights affect pancreatic development - Associated with type 2 diabetes later in life Symptoms Are Often Ignored for type 2 diabetes - answer-Type 2 diabetes can go undiagnosed because symptoms develop gradually: - Fatigue - Frequent urination - Excessive thirst Managing Type 2 Diabetes - answer-- Keeping blood glucose near normal range reduces risk of complications: -- Weight management -- Regular exercise -- Healthy diet - Some people also benefit from medications: -- Insulin -- Drugs that increase insulin sensitivity Physical Activity and Type 2 Diabetes - answer-Benefits of regular activity and physical activity are substantial: - Facilitates weight loss and maintenance - Improves insulin sensitivity - Improves glucose regulation - Reduces blood pressure - Improves cardiovascular fitness - Decreases blood lipid levels Inherited metabolic disease - answer-Genetic condition cause by a deficiency or absence of one or more enzymes needed for a metabolic pathway to function properly Catabolic pathways - answer-A series of metabolic reactions that break down a complex molecule into simpler ones, often releasing energy in the process Anabolic pathway - answer-A series of metabolic reactions that require energy to make a complex molecule from simpler ones, often requiring energy in the process Amphibolic pathways - answer-Metabolic pathway that generates intermediate products that can be used for both catabolism and anabolism Calculating recommended total carbohydrate intake - answer- Which of the following is a similarity between glycogen and fiber? - answer-They are both classified as complex carbohydrates Which of the following statements is true of bioavailability? - answer-It can be influenced by the physiological needs of the body. Which of the following is true of type 1 diabetes? - answer-It is classified as an autoimmune disease. Which of the following is true of the process of photosynthesis? - answer-It produces glucose and oxygen. _____ is a naturally occurring monosaccharide found primarily in honey, fruits, and vegetables. - answer-Fructose Which of the following is a function of the gastrointestinal microbiota? - answer-It inhibits the growth of other disease-causing bacteria. Unlike irritable bowel syndrome, inflammatory bowel disease: - answer-is believed to develop when exposure to a substance causes an immunologic response. Salivary amylase is an enzyme released from the salivary glands that breaks some of the chemical bonds in__________. - answer-Starch The term _____ is used to describe a group of related plants that grow in some regions of Central and South America and whose leaves are used as artificial sweeteners. - answer-Stevia The Acceptable Macronutrient Distribution Range (AMDR) suggests that 45 to 65 percent of your total caloric intake should come from: - answer-Carbohydrates Which of the following statements is true of irritable bowel syndrome? - answer-It is believed to be caused by elevated levels of a neurohormone called serotonin Which of the following is true of ATP? - answer-It is produced by anaerobic catabolic pathways to prevent muscle fatigue during intense exercises. An abnormally low level of glucose in the blood is referred to as__________. - answer-hypoglycemia __________is a semi-liquid paste that results from the mixing of partially digested food with gastric juice in the stomach. - answer-Chyme After leaving the stomach, chyme passes into the first segment of the small intestine called the__________. - answer-Duodenum Carbohydrates comprise a diverse group of compounds produced primarily by: - answer-Plants Which of the following is a function of the gallbladder? - answer-It stores bile and releases it into the small intestine. A__________is a lymphatic vessel found in an intestinal villus into which nutrients circulate after they are absorbed. - answer-Lacteal Which of the following substances is found in gastric juice? - answer-Mucus The Recommended Dietary Allowance for carbohydrates is 130 grams per day for adults. This amount: - answer-is the minimum amount of glucose needed by the brain each day. Most of the fiber in a kernel of wheat is found in the: - answer-Bran _____ is defined as the sum of chemical processes that occur within a living cell to maintain life. - answer-Metabolism Which of the following is a difference between probiotic and prebiotic foods? - answer-Unlike probiotic foods, prebiotic foods are typically fiber-rich. The hormones insulin and glucagon are made and released by the _____. - answer-Pancreas The germ is the portion of a wheat kernel that contains most of the _____. - answer-Vitamins Which of the following statements is true of peristalsis? - answer-It propels food from one region of the gastrointestinal tract to the next. Lactose intolerance is caused by: - answer-The inability of the body to produce enough lactase. Sucrose is composed of: - answer-Fructose joined with glucose. __________is a process whereby chlorophyll-containing plants produce glucose by combining carbon dioxide (CO2) and water (H2O) using energy harvested from sunlight. - answer-Photosynthesis Which of the following statements is true of facilitated diffusion? - answer-It is the movement of a substance with the assistance of a carrier molecule. Jane is a college student who tends to stay up late and not eat enough food. Jane has lately been complaining about feeling tired and light headed throughout the day. In this scenario, Jane most likely has a condition called _____. - answer-Hypoglycemia Which of the following is true of fructose? - answer-The majority of fructose consumed in the Western diet comes from foods and beverages made with high-fructose corn syrup. Which of the following statements is true of homeostasis? - answer-Homeostasis can be disrupted by excessive intake of sugar. Which of the following is true of microvilli? - answer-They cover the lumenal surfaces of enterocytes. High-fructose corn syrup is: - answer-A widely used sweetener. Which of the following is true of a passive transport mechanism? - answer-It includes osmosis, simple diffusion, and facilitated diffusion. Which of the following is a difference between active and passive transport mechanisms? - answer-Unlike active transport mechanisms, passive transport mechanisms do not require adenosine triphosphate. Insulin can reduce blood glucose levels because it: - answer-Promotes the storage of glucose as glycogen in liver and skeletal muscle cells. Which of the following statements is true of nutrient circulation? - answer-Lymphatic vessels empty into the bloodstream where nutrients can be used by cells. The glycemic load (GL) is different from the glycemic index (GI) because: - answer-it takes into account the typical portion size of the food. Which of the following is true of the gastric mucosal barrier? - answer-It protects the stomach lining from acidic gastric juices. Fluids in the body contain different types of dissolved substances that are referred to as__________. - answer-Solutes Which of the following cell organelles converts the chemical energy of energy-yielding nutrients into ATP? - answer-The mitochondrion Glucose is stored as glycogen in: - answer-liver and skeletal muscle. Type 1 and type 2 diabetes are both associated with: - answer-frequent urination and excessive thirst. Which of the following is true of catabolic pathways? - answer-They can be both aerobic and anaerobic. Which of the following is true of high-fructose corn syrup? - answer-Cornstarch has to be treated with enzymes to manufacture high-fructose corn syrup. Insulin is released from the pancreas in response to: - answer-High blood glucose levels. Which of the following lists represents the levels of organization in the body, from the smallest to the largest? - answer-Atoms, molecules, macromolecules, cells, tissues, organs, and organ systems Which of the following is true of type 2 diabetes? - answer-It is caused by insulin resistance. Which of the following is true of excretion? - answer-It is the removal of metabolic waste products of cells. The process of photosynthesis combines _____ in the presence of sunlight to produce glucose and oxygen. - answer-Carbon dioxide and water Which of the following is a function of bile? - answer-It causes the dispersion of large globules of fat into smaller droplets. Plants store extra glucose as starch, whereas the human body stores small amounts of excess glucose in the form of__________. - answer-Glycogen Which of the following statements is true of elimination? - answer-The gastrointestinal tract and accessory organs carry out the process of elimination. Foods with a glycemic index (GI) of 70 are considered high-GI foods and: - answer-Result in a rapid increase in blood glucose levels. Which of the following statements is true of tissues? - answer-Muscle tissues in the human body are both voluntary and involuntary. Bruce is a healthy teenager. He suffers from stomach pain and swelling whenever he consumes dairy products such as milk and cheese. Bruce has a healthy appetite when it comes to nondairy products and does not suffer from any such discomfort when consuming them. He is most likely suffering from _____. - answer-Lactose intolerance Which of the following is true of active transport mechanisms? - answer-They require energy to move substances across cell membranes. Simple carbohydrate (or simple sugar) is a category of carbohydrates that comprises: - answer-Monosaccharides and disaccharides.