Nutritional Biochemistry Final
Cholecystokinin
(CCK): Secreted by I cells of proximal small intestine and enteric nerves, responds to the presence of fat and partially digested proteins in the duodenum
free energy
(G): potential energy released from bonds of energy, end products of macronutrients are co2 and h20, they have free energy such as heat.
Peptide YY
(PYY): Counters the effects of Cholecystokinin / is a hormone made in the small intestine. It helps to reduce appetite and limit food intake.
Pancreas
(helps facilitate digestion and absorption in the small intestine): ductless endocrine cells that secrete hormones into the blood (regulatory control by secreting glucagon from the alpha cells, insulin from the beta cells, somatostatin from the delta cells) , digestive enzymes produced by acinar exocrine cells (will release enzymes like protease, amylase, lipase), pancreatic juice contains (alkaline high pH): water, electrolytes, bicarbonate, pancreatic digestive enzymes, will travel from the pancreatic duct into the common bile duct through the sphincter of oddi to the duodenum
The Small Intestine
(main site for digestion and absorption): composed of duodenum, jejunum, and ileum
The liver
(the largest organ in the body, produces bile): consists of lobes made of lobules, portal circulation, bile canaliculi, bile synthesis and function: bile composed of bile acids and salts, cholesterol, phospholipids, and bile pigments in alkaline solution, bile acts as detergent to emulsify fat, breaking the fat down from large parts into small droplets and forming my? Cells
Describe how the structure of the small intestine enhances the digestive and absorptive capacity of the human body.
-Folds of Kerckring: large, circular folds of mucosa -Villi: finger like projections -Microvilli: hair like extensions of the cells plasma membranes -Brush border -Crypts of Lieberkuhn -all of these structures increase the surface area of the small intestine and this is needed for proper digestion and absorption of nutrients
Glycosidic bonds
A glycosidic bond or glycosidic linkage is a type of covalent bond that joins a carbohydrate (sugar) molecule to another group, which may or may not be another carbohydrate.
Cori cycle
AKA the lactic acid cycle / is a metabolic pathway in which lactate produced by anaerobic glycolysis in muscles is transported to the liver and converted to glucose, which then returns to the muscles and is cyclically metabolized back to lactate
What is ATP? Why is it important? How is ATP generated?
ATP functions as the energy currency for cells. It allows the cell to store energy briefly and transport it within the cell to support endergonic chemical reactions. because it transports the energy necessary for all cellular metabolic activities. It is dubbed as the universal unit of energy for living organisms. Oxidative phosphorylation: electron transport chain (AKA electron transport system, respiratory chain
Why are enzymes often compartmentalized within a cell?
All reactions occurring in cells take place in certain space - compartment, which is separated from other compartments by means of semipermeable membranes. They help to separate even chemically quite heterogeneous environments and so to optimize the course of chemical reactions.
Amylin
Amylin is a peptide hormone that is cosecreted with insulin from the pancreatic β-cell and is thus deficient in diabetic people. It inhibits glucagon secretion, delays gastric emptying, and acts as a satiety agent.
How do broad-spectrum antibiotics impact the beneficial effects of our gut flora?
Antibiotic treatment reduces the overall diversity of gut microbiota species, including loss of some important taxa, which causes metabolic shifts, increases gut susceptibility to colonization, and stimulates the development of bacterial antibiotic resistance
Who is most likely to have difficulty maintaining adequate iron stores and why?
Because women lose blood during menstruation, women in general are at greater risk of iron deficiency anemia. Infants and children. Infants, especially those who were low birth weight or born prematurely, who don't get enough iron from breast milk or formula may be at risk of iron deficiency.
Bile
Bile is a fluid that is made and released by the liver and stored in the gallbladder. Bile helps with digestion. It breaks down fats into fatty acids, which can be taken into the body by the digestive tract
Describe the possible role calcium plays in the development of hypertension.
Calcium intake may regulate blood pressure by increasing intracellular calcium in vascular smooth muscle cells leading to vasoconstriction, and by increasing vascular volume through the renin-angiotensin-aldosterone system (RAAS)
Discuss how calcium status is assessed and current recommendations for reducing the risk of osteoporosis.
Calcium status may best be assessed by integrated measures of calcium assimilation, such as total-body calcium. Although bone-mass measurements do not correlate well with recent dietary intakes of calcium, long-term adequacy of calcium intake influences bone mass.
steps of protein synthesis and location
Cell signaling (communicates the need to synthesize a protein to the nucleus) (ribosomes) Transcription (of a gene in the in the nucleus results in the synthesis of a strand of mRNA) (nucleus) Translation and Elongation (the mRNA strand leaves the nucleus, binds to the ribosomes, and directs protein translation with the help of tRNA subunits and their associated amino acids (ribosomes) The elongation process results in the production of a peptide strand (Ribosomes)
Chief cells
Chief cells are responsible for secreting pepsinogen. They have basally located nuclei and a basophilic cytoplasm with abundant rough endoplasmic reticulum and many secretory granules that contain pepsinogen. These are secreted into the lumen of the gastric gland.
What is cAMP and why is it important?
Cyclic adenosine monophosphate (cyclic AMP), Ion channel; receptor for acetylcholine, Internalize stimulus; variety of biologically active molecules, several hormones / is a second messenger, used for intracellular signal transduction, such as transferring into cells the effects of hormones like glucagon and adrenaline, which cannot pass through the plasma membrane. It is also involved in the activation of protein kinases.
What dietary factors are associated with greater diversity of gut microflora? What possible health benefits may be associated with more diversity and why?
Eat a Diverse Range of Foods. ... Eat Lots of Vegetables, Legumes, Beans and Fruit. ... Eat Fermented Foods. ... Don't Eat Too Many Artificial Sweeteners. ... Eat Prebiotic Foods. ... Breastfeed for at Least Six Months. ... Eat Whole Grains. ... Eat a Plant-Based Diet. Improved immune system, better food digestion, increased metabolism of food and drugs
Endocrine glands
Endocrine glands release hormones into the bloodstream. This lets the hormones travel to cells in other parts of the body. The endocrine hormones help control mood, growth and development, the way our organs work, metabolism , and reproduction.
How does a newly synthesized protein find its appropriate membrane? What role do receptors play in this?
Endoplasmic Reticulum (ER): Network of membranous channels used to communicate from the innermost part of the cell to the exterior. Types of ER: Rough ER (studded with ribosomes): protein synthesis, Smooth ER: lipid synthesis, Sarcoplasmic reticulum (SER in the muscles): calcium ion pump used in muscle contractions
Outline the basic ways in which the activity of enzymes is regulated.
Enzyme inhibitors are molecules that interact with enzymes (temporary or permanent) in some way and reduce the rate of an enzyme-catalyzed reaction or prevent enzymes to work in a normal manner. The important types of inhibitors are competitive, noncompetitive, and uncompetitive inhibitors.
Explain why children excrete less fluoride in their urine than adults do. How is fluoride absorbed?
Fluoride plays a role in the mineralization of your bones and teeth, a process essential for keeping them hard and strong. In fact, about 99% of the body's fluoride is stored in bones and teeth. Fluoride is also important for preventing dental caries, also known as cavities.
Glucogenic amino acids
Generates alpha-ketoglutarate (used in the TCA cycle) / A glucogenic amino acid is an amino acid that can be converted into glucose through gluconeogenesis. ... The production of glucose from glucogenic amino acids involves these amino acids being converted to alpha keto acids and then to glucose, with both processes occurring in the liver.
Describe the absorption of monosaccharides and the fate of each.
Glucose, galactose and fructose are tranported out of the enterocyte through another hexose transporter (called GLUT-2) in the basolateral membrane. These monosaccharides then diffuse "down" a concentration gradient into capillary blood within the villus. Facilitated transport: Diffusion, GLUT2, especially utilized after high carbohydrate meals, this will trigger insulin secretion into the bloodstream, in type 2 diabetes GLUT2 does not respond the same way Intestinal absorption of fructose: it is different than glucose and galactose, we only absorb only about 50% of the fructose that enters into the small intestine
glucose-dependent insulinotropic polypeptide
Glucose-dependent insulinotropic peptide is a hormone produced by the small intestine in response to eating food. Its main action is to encourage the release of insulin into the bloodstream to control blood sugar levels.
List foods containing goitrogens and describe how they affect iodide update in the thyroid.
Goitrogenic foods include Brussel sprouts, kohlrabi, turnips, rutabaga, radishes, cabbage, kale, and cauliflower. Goitrogens have been shown to inhibit thyroid hormones synthesis in several ways, mostly by inhibiting iodine utilisation. Those micronutrients have to be taken in consideration specially in those with thyroid diseases or who are iodine deficient
Describe how the immune system protects the GI tract and why this is important.
Gut-associated lymphoid tissue (GALT): Mucosa and submucosa (within these two, there is immunal protection for leukocytes, plasma cells, Natural killer cells, macrophages, MK cells, dendritic cells, and others),
Explain what hemoglobin and hematocrit are and how they indicate iron status.
Hemoglobin is the iron-based molecule type that gives blood its red color and ferries oxygen to the rest of the body. Hemoglobin is a protein in red blood cells and hematocrit is a measurement of the amount of red blood cells as related to total blood cell count.
How does hemoglobin carry oxygen?
Hemoglobin. Hemoglobin, or Hb, is a protein molecule found in red blood cells (erythrocytes) made of four subunits: two alpha subunits and two beta subunits. Each subunit surrounds a central heme group that contains iron and binds one oxygen molecule, allowing each hemoglobin molecule to bind four oxygen molecules.
briefly describe how cellular protein receptors function as ion channels.
Ion channel-linked receptors bind a ligand and open a channel through the membrane that allows specific ions to pass through. To form a channel, this type of cell-surface receptor has an extensive membrane-spanning region.
Outline the process by which blood calcium levels are maintained, including the roles of calcitriol (1,25 -[OH]2 vitamin D3,) calcitonin and parathyroid hormone.
It maintains serum calcium levels by increasing calcium absorption in the gastrointestinal tract. It promotes healthy bone formation by the calcification of osteoid tissue. It also directly inhibits parathyroid gland activity by decreasing parathyroid hormone synthesis and release. Parathyroid hormone acts to increase blood calcium levels, while calcitonin acts to decrease blood calcium levels. This interaction between parathyroid hormone and calcitonin is also an important part of bone remodeling.
Oral Cavity
Its primary function is to serve as the entrance of the alimentary tract and to initiate the digestive process by salivation and propulsion of the alimentary bolus into the pharynx.
lactose intolerance
Lactose intolerance is usually caused by a deficiency of an enzyme in the body called lactase / Symptoms can include abdominal cramps, bloating, and diarrhea.
How is magnesium associated with bone mineralization?
Magnesium deficiency contributes to osteoporosis directly by acting on crystal formation and on bone cells and indirectly by impacting on the secretion and the activity of parathyroid hormone and by promoting low grade inflammation.
Motilin
Motilin is the hormone that is cyclically released during the fasted state and is released by the entero-endocrine cells (Mo cells) in the upper small intestine. Motilin stimulates gastric and small intestine motility, causing undigested food in these regions to move into the large intestine.
esphagus
Moves bolus (food mixed with saliva) from oral cavity to stomach
What role does magnesium play in maintaining calcium homeostasis?
Normally, the parathyroid glands release a hormone that increases blood calcium levels when they are low. Magnesium is required for the production and release of parathyroid hormone, so when magnesium is too low, insufficient parathyroid hormone is produced and blood calcium levels are also reduced (hypocalcemia)
Oligosaccharide
Oligosaccharides (3-10 sugar units, raffinose, stachyose, verbascose, dextrins, formed by long chains of monosaccharides connected by covalent bonds)
parietal cells
Parietal cells (also known as oxyntic cells) are epithelial cells in the stomach that secrete hydrochloric acid (HCl) and intrinsic factor. ... They contain an extensive secretory network of canaliculi from which the HCl is secreted by active transport into the stomach.
Describe how to lessen and/or manage gastrointestinal reflux disease and ulcers.
People will need to establish trigger foods that cause this, it is treated with medication / Maintain a healthy weight. ... Stop smoking. ... Elevate the head of your bed. ... Don't lie down after a meal. ... Eat food slowly and chew thoroughly. ... Avoid foods and drinks that trigger reflux. ... Avoid tight-fitting clothing.
What is the basis for replacing some of NaCl in the diet with KCI and how does it work?
Potassium chloride (KCl) is a potassium salt form that occurs naturally, typically extracted from ground or sea. When used in food manufacturing, potassium chloride can replace sodium chloride (table salt) and can help reduce sodium by up to 50% in certain applications.
What are probiotics and prebiotics and what roles might each play in intestinal health? What foods are sources of probiotics?
Probiotics: live microorganisms, guest bacteria that are just passing through, they are not permanent, little or no health benefits for most people, can hurt people with aids, cancer, organ transplant patients, or anyone with a hindered immune system -Benefits: improve symptoms of irritable bowel syndrome, inflammatory bowel diseases, and some type of diarrhea, benefits found with higher consumption of fruits, vegetables, whole grains, legumes and fermented foods, these will help promote the health and diversity of healthy bacteria, do not take supplements, as a diet rich in whole grains and fiber has been very beneficial -Sources: Yogurt. Yogurt is one of the best sources of probiotics, which are friendly bacteria that can improve your health. ... Kefir. Kefir is a fermented probiotic milk drink. ... Sauerkraut. ... Tempeh. ... Kimchi. ... Miso. ... Kombucha. ... Pickles. Prebiotics: act as substrates for healthy bacteria, help support the metabolism of the healthy bacteria, most prebiotics are dietary fibers, but not all dietary fiber have prebiotic natures
cell replication
Replication is the process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules. Each time a cell divides, the two resulting daughter cells must contain exactly the same genetic information, or DNA, as the parent cell.
Carbohydrate
Simple Carbohydrates: monosaccharides (1 sugar unit,glucose, fructose, galactose, they can not be reduced any further in hydrolysis), and disaccharides (2 sugar units, lactose, sucrose, maltose, and trehalose, connected by covalent bonds, sharing of electrons pairs between atoms) Complex carbohydrates: Oligosaccharides (3-10 sugar units, raffinose, stachyose, verbascose, dextrins, formed by long chains of monosaccharides connected by covalent bonds), and polysaccharides (10 or more sugar units, dextrins, starch, glycogen, dietary fiber)
Describe mechanisms used to transport nutrients across cell membranes.
Simple Diffusion: simple diffusion is a form of diffusion that does not require the assistance of membrane proteins. In essence, the particle or substance moves from higher to lower concentration. Facilitated diffusion is the transport of substances across a biological membrane from an area of higher concentration to an area of lower concentration with the help of a transport molecule. Primary active transport, also called direct active transport, directly uses chemical energy (such as from adenosine triphosphate or ATP in case of cell membrane) to transport all species of solutes across a membrane against their concentration gradient. secondary active transport: A method of transport in which the electrochemical potential difference created by pumping ions out of the cell is used to transport molecules across a membrane.
Somatostatin
Somatostatin is a hormone produced by many tissues in the body, principally in the nervous and digestive systems. It regulates a wide variety of physiological functions and inhibits the secretion of other hormones, the activity of the gastrointestinal tract and the rapid reproduction of normal and tumour cells
Compare the overall structures of starch, glycogen and cellulose. How do structural differences impact their use in the body?
Starch: Amylose is an unbranched, coiled chain and amylopectin is a long branched chain, of which some are coiled. (very common in plants, how they store energy) Cellulose: Cellulose is a straight, long, unbranched chain, which forms H-bonds with adjacent chains. (our bodies cannot break it down but gut microbiota can) Glycogen: Glycogen is a short, many branched chains of which some chains are coiled (high branched chain amino acids, makes it easier for our body to use)
An "average" college student is eating an "average" diet. He has decided to take a supplement of minerals that includes: 150% RDA of Zn, Ca, Cu and Fe. What would your recommendation be and defend your answer.
Stop taking the supplement and get nutrients from the foods you are eating
Many people's diets are deficient in calcium as well as iron. What effect does taking a calcium supplement have on iron absorption? What advise would you give to a client/patent who needed to maximize the benefit from both of these key minerals?
Studies on human subjects have shown that calcium (Ca) can inhibit iron (Fe) absorption, regardless of whether it is given as Ca salts or in dairy products. This has caused concern as increased Ca intake commonly is recommended for children and women, the same populations that are at risk of Fe deficiency. Spread out time of consumption! Short duration
Substance P
Substance P's most well-known function is as a neurotransmitter and a modulator of pain perception by altering cellular signaling pathways. Additionally, substance P plays a role in gastrointestinal functioning, memory processing, angiogenesis, vasodilation, and cell growth and proliferation.
At the beginning of the COVID-19 pandemic, silver supplements were being promoted by non-health professionals. This supplement resurfaces periodically, and you are likely to see it in your time as a professional. If your client asked you about taking these supplements, what would your response be? (Registered Dietitian Nutritionists and nutrition professionals utilize evidence-based resources in their responses.)
Supplements containing colloidal silver aren't considered safe or effective for any of the health claims manufacturers make. Silver has no known purpose in the body. It's not an essential mineral. They claim it can boost your immune system, ease chest congestion, and treat or prevent viral infections like the common cold or COVID-19.
neural regulation of digestion
The brain and the endocrine system control digestive processes. The brain controls the responses of hunger and satiety. The endocrine system controls the release of hormones and enzymes required for digestion of food in the digestive tract.
Brush Boarder
The brush border membrane, consisting of the micro- villous border and glycocalyx, appears to constitute a part of the epithelial cell membrane and also a part of the mucous layer (10, 11). It represents a part of the intestinal barrier, capable of digestion and absorption of end products of ingested food.
A critical care dietitian notes that many of her patients with infections have laboratory values indicative of anemia. Why might it be important to identify if each patient had a history of iron deficiency before recommending aggressive iron therapy?
The diagnosis of iron deficiency anemia is confirmed by the findings of low iron stores and a hemoglobin level two standard deviations below normal. Women should be screened during pregnancy, and children screened at one year of age.Jan 15, 2013 At high doses, iron is toxic. For adults and children ages 14 and up, the upper limit -- the highest dose that can be taken safely -- is 45 mg a day. Children under age 14 should not take more than 40 mg a day.
Outline the major steps of carbohydrate digestion including sites, enzymes involved, and end products.
The digestion of carbohydrates begins in the mouth. The salivary enzyme amylase begins the breakdown of food starches into maltose, a disaccharide. The next step of carbohydrate digestion takes place in the duodenum. Recall that the chyme from the stomach enters the duodenum and mixes with the digestive secretion from the pancreas, liver, and gallbladder. Pancreatic juices also contain amylase, which continues the breakdown of starch and glycogen into maltose, a disaccharide. The disaccharides are broken down into monosaccharides by enzymes called maltases
Steps of digestion and absorption
The digestive system ingests and digests food, absorbs released nutrients, and excretes food components that are indigestible. The six activities involved in this process are ingestion, motility, mechanical digestion, chemical digestion, absorption, and defecation.
The Gallbladder
The gallbladder functions as a concentrating reservoir for bile, which it delivers to the duodenum in response to meals.
What roles do gut microbiota and their metabolites play in terms of our physiology?
The gut microbiota regulates immune homeostasis via the induction of regulatory T cells and Th17 cells. In addition, butyrate has strong anti-inflammatory effects possibly through the inhibition of histone deacetylase activity.
Immune system's connection to digestive system
The lining of the gut has the distinct responsibility of filtering nutrients into the bloodstream and keeping undigested particles and toxins from entering. When this border becomes damaged, the body alerts the immune system to respond, causing a reaction
How might mineral nutriture affect the development and management of hypertension?
The mineral elements sodium, potassium, calcium and magnesium play a central role in the normal regulation of blood pressure. In particular, these mineral elements have important interrelationships in the control of arterial resistance.
Mucosa
The mucosa is the innermost layer, and functions in absorption and secretion. It is composed of epithelium cells and a thin connective tissue. The mucosa contains specialized goblet cells that secrete sticky mucus throughout the GI tract.
Prostaglandins
The prostaglandins are a group of lipids made at sites of tissue damage or infection that are involved in dealing with injury and illness. They control processes such as inflammation, blood flow, the formation of blood clots and the induction of labour
Describe how gastric emptying is controlled and why the control is important.
The rate of gastric emptying is controlled by humoral and nerval factors. When glucose, fat, or amino come into contact with the duodenal mucosa inhibitory mechanisms decrease the fundic pressure and thereby slow the gastric emptying of nutrients. It is important because the presence of fat in the small intestine inhibits GE, ingestion of fat may attenuate the glycemic response to carbohydrate.
vagus nerve
The vagus nerve is responsible for the regulation of internal organ functions, such as digestion, heart rate, and respiratory rate, as well as vasomotor activity, and certain reflex actions, such as coughing, sneezing, swallowing, and vomiting
Discriminate among hemoglobin, transferrin and ferritin in terms of iron balance. Explain how you can use each to identify the stages of iron deficiency.
Transferrin is the main protein in the blood that binds to iron and transports it throughout the body. A transferrin test directly measures the level in the blood.Apr 20, 2021 Iron is an essential element for blood production. About 70 percent of your body's iron is found in the red blood cells of your blood called hemoglobin and in muscle cells called myoglobin. Hemoglobin is essential for transferring oxygen in your blood from the lungs to the tissues. Ferritin is a blood protein that contains iron. A ferritin test helps your doctor understand how much iron your body stores. If a ferritin test reveals that your blood ferritin level is lower than normal, it indicates your body's iron stores are low and you have iron deficiency. As a result, you could be anemic
An elderly man with diabetes mellitus was told by the salesperson at the local health food store to take chromium and vanadium. What is the basis for this? What would you recommend?
Vanadium seems to decrease blood sugar in people with type 2 diabetes. Diabetes medications are also used to lower blood sugar. Taking vanadium along with diabetes medications might cause your blood sugar to go too low. Chromium picolinate, specifically, has been shown to reduce insulin resistance and to help reduce the risk of cardiovascular disease and type 2 diabetes. Dietary chromium is poorly absorbed. Chromium levels decrease with age.
Explain the influences of zinc on carbohydrate metabolism, BMR, and taste.
Zinc is needed by pancreatic beta-cells for production of insulin and thus influences carbohydrate metabolism. Zinc deficiency causes impaired glucose tolerance. Zinc is important for thyroid hormone production and so zinc deficiency can result in a lower BMR. Zinc is a component of gustin, which is important for perception of taste sensations.
nucleic acids
a complex organic substance present in living cells, especially DNA or RNA, whose molecules consist of many nucleotides linked in a long chain.
Ribosomes
a minute particle consisting of RNA and associated proteins found in large numbers in the cytoplasm of living cells. They bind messenger RNA and transfer RNA to synthesize polypeptides and proteins.
transition state
chemical reaction is a particular configuration along the reaction coordinate. It is defined as the state corresponding to the highest potential energy along this reaction coordinate. It is often marked with the double dagger ‡ symbol.
Disaccharides
disaccharides (2 sugar units, lactose, sucrose, maltose, and trehalose, connected by covalent bonds, sharing of electrons pairs between atoms)
exothermic reactions
energy releasing, downhill reactions, end product is usually ATP or heat / chemical reaction in which less energy is needed to break bonds in the reactants than is released when new bonds form in the products.
Endothermic reaction
energy requiring, uphill reactions, they need energy to happen / any chemical reaction that absorbs heat from its environment.
activation energy
energy to raise reactants to translation state, exothermic reactions are favored, but need the activation energy to get going.
glycocalyx
is a highly charged layer of membrane-bound biological macromolecules attached to a cell membrane. ... Glycocalyx also serves as a mediator for cell-cell interactions and protects a cell membrane from the direct action of physical forces and stresses allowing the membrane to maintain its integrity.
Phagocytosis
is the process by which a cell uses its plasma membrane to engulf a large particle, giving rise to an internal compartment called the phagosome
Translation
mRNA codes for amino acid sequence to form proteins, synthesized in the nucleus, then moves to the RER in the cytoplasmic matrix, codons: 3-base sequence that codes amino acids, tRNA brings amino acids to mRNA on ribosomes.
endocrine system
made up of all the body's different hormones, regulates all biological processes in the body from conception through adulthood and into old age, including the development of the brain and nervous system, the growth and function of the reproductive system, as well as the metabolism and blood sugar
Monosaccharides
monosaccharides (1 sugar unit,glucose, fructose, galactose, they can not be reduced any further in hydrolysis, 3-7 carbon atoms)
Regulatory Peptides
more than 100 known peptides that can impact GI function): Hormones (gastrointestinal hormones), and Paracrines, most work as endocrines, stimuli triggers them to be released into the blood and travel to a region where they will make a change
Peristalsis
nervous system triggers this process (peristalsis) as the food moves down the esophagus, stretching and stimulating smooth muscle, into the stomach, then into the colon.
salivary glands
parotid, submandibular, sublingual, Enzymes in saliva (used to start to break down starch), saliva will also have other solutes and electrolytes in it. / Saliva helps with swallowing and chewing. It can also help prevent infections from developing in your mouth or throat.
Polysaccharide
polysaccharides (10 or more sugar units, dextrins, starch, glycogen, dietary fiber)
Secretin
produced by S cells in the proximal small intestine, responds to the presence of acidic chyme
Describe the process of apoptosis in relation to the lifespan of the cell.
programmed cell death, cells have a lifespan and wear out, they need to be replaced / It is used during early development to eliminate unwanted cells; for example, those between the fingers of a developing hand. In adults, apoptosis is used to rid the body of cells that have been damaged beyond repair.
Glucagon-like peptide 1 (GLP-1)
stimulates pancreas to secrete insulin, while inhibiting glucagon secretion -Occurs along the entire length of the intestine in proportion to caloric intake -Slows gastric emptying and intestinal motility through vagus nerve in the brain
Gastrin
stimulation of acid secretion from gastric parietal cells and stimulation of mucosal growth in the acid-secreting part of the stomach. Circulating gastrin regulates the increase in acid secretion that occurs during and after meals.
The Stomach
temporary storage for food, which passes from the esophagus to the stomach where it is held for 2 hours or longer. mixing and breakdown of food by contraction and relaxation of the muscle layers in the stomach. digestion of food.
genetic code
the A, C, G, and Ts--are strung together in a way that the cellular machinery, the ribosome, can read them and turn them into a protein. In the genetic code, each three nucleotides in a row count as a triplet and code for a single amino acid.
Autolysis
the destruction of cells or tissues by their own enzymes, especially those released by lysosomes.
Chyme
the first is to increase the surface area of food to allow digestive enzymes to complete their work, and the second is to stimulate various digestive glands to release their secretions
Transcription
the process by which the information in a strand of DNA is copied into a new molecule of messenger RNA (mRNA)
Why does the pH at various parts of the digestive tract differ and what are the consequences of this?
the stomach, must supply enough acid to break the food into its nutrients. However, when the food continues into the intestines, it no longer needs acid. Both intestines bring the matter closer to the pH of the body. In order to properly break down food
The large intestine
to absorb water and salts from the material that has not been digested as food, and get rid of any waste products left over.
Exocine glands
will release enzymes like protease, amylase, lipase
Describe what dietary recommendations you would make to increase the absorption of each of the following minerals:
· Calcium: vitamin D · Iron: vitamin c · Zinc: amino acids, histidine and methionine
List five dietary factors that influence iron absorption and indicate what each factor does.
· Sugars serve as ligands and that help the absorption of iron · Acids (lactate, ascorbate, citrate) act as reducing agents to increase absorption · Meats poultry, and fish promote absorption, although the mechanism is unclear · Phytic acid and oxalic acid both from insoluble complexes with iron that keep it from being absorbed · Antacid medications inhibit absorption by making the environment more alkaline