Midterm #1 Flashcards
(266 cards)
1
Q
What is nutrition?
A
science that studies all the interactions that occur between living organisms and food
2
Q
What are nutrients?
A
chemical substances in foods that provide energy and structure and help regulate body processes
3
Q
What gives us access to previously/quickly prepared foods with little effort?
A
processed foods and fast foods
4
Q
When did processed foods/fast foods arise?
A
21st century
5
Q
How do processed/fast foods differ in nutritional value from other foods?
A
higher in calories, lower in other nutrients (vitamins, minerals, antioxidants); makes it easier to overeat because they’re so available
6
Q
What is the focus of nutrition advice in modern America?
A
controlling intake, just as much as ensuring adequate intake
7
Q
kilocalorie
A
unit of heat used to express the amount of energy provided by foods; heat required to raise temperature of 1 kg of water 1 degree C (1 kcal = 4.18 J)
8
Q
how many joules per kcal?
A
4.18 kjoules = 1 kcal
9
Q
macronutrient
A
needed in large amounts; water, carbs, protein, lipids
10
Q
micronutrient
A
needed in small amounts; vitamins and minerals
11
Q
What are lipids?
A
organic, energy-yielding, macronutrient, NOT water-soluble; fatty acids/triglycerides/cholesterol
12
Q
What are proteins?
A
organic, energy-yielding, macronutrient, water-soluble, made of amino acids
13
Q
What are vitamins?
A
organic, not energy yielding, micronutrients, some water-soluble, some fat-soluble
14
Q
What are minerals?
A
inorganic, not energy-yielding, micronutrients, water-soluble
15
Q
What is undernutrition?
A
malnutrition: deficiency of energy and/or nutrients
16
Q
What is overnutrition?
A
malnutrition: excess energy and/or nutrients
17
Q
How does overnutrition differ for energy vs vitamins/minerals?
A
energy: obesity, chronic illness (diabetes, etc.); vit/min = organ damage and/or death
18
Q
What is malnutrition?
A
any condition resulting from an energy or nutrient intake either above or below that which is optimal for a period of time
19
Q
How does someone get overnutrition of energy but undernutrition of vitamins/minerals?
A
by eating a diet high in processed foods: lots of energy but low in vitamins/minerals
20
Q
How do genetics influence nutrition?
A
can influence predisposition to diseases like diabetes/cancer; diet an increase risk or decrease if healthful
21
Q
What effect can diet have on genetic predispositions to disease?
A
if unhealthy, can exacerbate; if healthy, can alleviate
22
Q
What is nutritional genomics?
A
new field of study exploring interaction between genetic variation and nutrition
23
Q
What field of study explores the interaction between genetic variation and nutrition?
A
nutritional genomics
24
Q
What determines food choices?
A
availability, cultural and family background, prior experience, social acceptability, personal preference, psychological/emotional state, health concerns, taste, cost nutrition, convenience
25
What are the main determinants for what we eat?
taste, cost, nutrition, convenience
26
How can we choose a healthy diet?
identify and choose nutrient dense foods; varied diet; balance choices and use moderation, be aware of portion sizes
27
What is a nutrient dense food?
contains more nutrients per calorie
28
Why can nutrition science seem contradictory?
because science takes a whole: study designs/interpretation/media effects may differ from study to study
29
What is the scientific method?
systematic, unbiased approach to evaluating the relationships among food, nutrients, and health
30
What are the steps to the scientific method?
PIHERC (problem, info, hypothesis, experiment, results, conclusion, revise)
31
What are the steps to the scientific method?
PIHERC (problem, info, hypothesis, experiment, results, conclusion, revise)
32
How can an experiment generate reliable theories?
must produce consistent quantificable results and interpreted accurately
33
What are three ways that scientists study nutrition?
observational/epidemiological studies; human intervention/clinical trials; lab studies
34
What are observation/epidemiological studies?
can't determine cause/effect, only identify patterns; often case-control studies (to compare groups of people to look for patterns)
35
What are human intervention/clinical trials?
can identify case/effect if designed well; variables carefully controlled by researchers
36
What are laboratory studies?
can include clinical trials; often involves cells in petri dish, chemical reactions, animals, humans, etc. can include depletion-repletion studies and balance studies
37
What is a depletion-repletion study?
eliminate nutrient until deficiency signs appear, then return nutrient until symptoms disappear
38
What are balance studies?
compare total amount of nutrient entering body to total amount leaving body
39
How do we resolve ethical concerns in scientific study?
both humans and animals are protected by federal laws and guidelines about research ethics
40
How can we evaluate nutrition information?
does the info make sense? What's the source? Is it good science? Has it stood the test of time?
41
What does it mean to ask about the source of nutrition information?
is it coming from a company trying to sell a product? Trust RDs and research universities
42
What does it mean to ask if nutrition info is based in good science?
well-designed, interpreted correctly, published in respected peer-reviewed journal
43
What does it mean to ask if nutrition info has stood the test of time?
have multiple similar studies found similar results?
44
Why do nutrition recommendations exist?
to give people guidance for ensuring a diet that provides adequate amounts of calories and nutrients, and that reduces the risk of specific diseases
45
When was the first set of recommendations published by the USDA?
1894
46
What is MyPlate?
introduced by government in 2011: current government guidance for food intake
47
What are RDAs?
recommended dietary allowances: designed to make recommendations of intakes for specific nutrients; developed in 1940s
48
When were RDAs started?
1940s
49
What are the three ways of early US food guidance?
food groups, MyPlate, recommended dietary allowances
50
How has the focus of dietary guidance changes throughout the last 100 years?
originally, designed to prevent nutrient deficiencies; but since those are now rare in the US, chronic diseases due to overnutrition have increased: newer recommendations are designed to promote health against overnutritions: Dietary Reference Intakes
51
Why were Dietary Reference Intakes developed?
to adjust US food guidelines for the impact of overnutrition: both prevents deficiencies and promotes health
52
What is a Dietary Reference Intake?
set of reference values for the intake of energy, nutrients, and food components that can ve used for planning/assessing the diets of healthy people in the US/Canada; includes EARs, RDAs, Ais, Uls, EERs, AMDRs
53
What are EARS?
estimated average requirements: intakes that meet the estimated nutrient needs of 50% of individuals in a gender and life-stage group
54
What are RDAs?
recommended dietary allowances: ) Intakes that are sufficient to meet the nutrient needs of almost all healthy people in a specific life-stage and gender group
55
What are Ais?
adequate intakes: Intakes that should be used as a goal when no RDA exists. These values are an approximation of the average nutrient intake that appears to sustain a desired indicator of health.
56
What are Uls?
tolerable upper intake levels: maximum daily intakes that are unlikely ot pose a risk of adverse health effects to almost all individuals in the specified life-stage and gender group
57
What are EERS?
estimated energy requirements: Average energy intakes predicted to maintain body weight in a healthy individual. Variables in the calculations include age, gender, weight, height, and level of physical activity
58
What are AMDRs?
acceptable macronutrient distribution ranges: Ranges of intake for energy-yielding nutrients, expressed as a percentage of total energy intake, that are associated with reduced risk of chronic disease while providing adequate intakes of essential nutrients
59
How can we apply DRIs?
to plan diets, assess adequacy of diets, make judgments about excessive intakes for individuals and populations; can't be used to identify whether a person has nutritional deficiency/excess
60
What are dietary guidelines?
suggest overall diet and lifestyle choices that will promote health; evidence-based nutritional guidanec; focus on balancing energy intake with physical activity, nutrient-dense foods, designed for Americans 2 yo and up
61
What ages are dietary guidelines for?
2yo and up
62
What is the minimum amount of moderate exercise recommmended each week?
150 minutes
63
What is the recommended intake for vegetables and fruits?
at least 2.5 cups per day (5 servings); improve choices by selecting variety, especially dark-green and red/orange vegetables, beans, peas
64
What is the recommended intake for whole graings?
at least half of grain servings are whole grains
65
What is the recommended intake for dairy?
limit consumption of high-fat dairy products like cheese
66
What is the recommended intake for proteins?
emphasis on plant-based proteins (legumes, nuts) and lean animal proteins; vary by choosing seafood
67
What are food and food components to reduce?
trans Fas, saturated fats, cholesterol, refined grains/sguars, processed foods, sodas/sugary drinks, fried foods, desserts and other high-sugar refined-grain foods; excess salt/sodium, excess alcohol
68
What are some of the food label changes from May 2016?
serving size bolded, calories in larger font and bolded, actual amount of vitamin C, calcium, iron, potassium; amount of added sugars
69
How is the ingredient list ordered?
by weight; must also list food colors and flavorings
70
What are some dietary supplements?
vitamins, minterals, herbs, botanicals, plant-derived substances, amino acids, enzymes, concentrates, extract
71
What are dietary supplement label requirements?
must contain words "dietary supplement" and carry "supplementary facts" listing recommended serving size and name/quantity of each ingredient per serving; directions for use and info about ingredients
72
What is DSVP?
dietary supplement verification program: meets manufacturing standards, but not necessarily safe/effective
73
Do dietary supplements need to be approved by the FDA?
nope
74
Are restaurants required to label food?
not unless the food is from a food establishment that has 20 or more locations
75
How are exchange lists used?
meal-planning tool for individuals: divides foods into groups (vegetables, fruits, starch, dairy, fat, protein); each serving contains approximately the same amount of energy/carbs/protein/fat: any one of the foods on a list can be exchanged with any other food on the list while maintaining nutritional impact
76
What is nutritional status?
state of health as it is influenced by the intake and utilization of nutrients
77
How to assess individual's nutritional status?
use assessment tools (analyzing nutrient intake, anthropometric measurements, medical history, physical exam, laboratory measurements)
78
"analyzing nutrient intake" assessment?
info about food intake gathered, then nutrient content compared to recommended intakes
79
"anthropometric measurements" assessment?
involve assessments of height, weight, body size; compared with population standards or used to monitor changes in individual over time
80
"medical history" assessments?
medical history examined for nutritional impact
81
"physical exam" assessments?
careful physical to detect symptoms of/risk factors for nutrition-related diseases
82
"laboratory measures" assessments?
measures of nutrients or byproducts in body cells/fluids like blood/urine can detect nutrient deficiencies/excesses
83
How to assess nutritional health of population?
monitor food supply and nutritional status
84
How to monitor food supply of population?
year-to-year comparisons, identify diet trends; but tend to oversetimate actual intame because don't consider losses during processing, marketing, home use, etc.
85
What are food disappearance surveys?
estimate food available to population; measure what food is sold
86
How do you monitor nutritional status of population?
examine/compare trends in food intake and health by interviewing individuals within population to determine what food is actually consumed and colelcting info on health and nutritional status
87
What is NHANES?
Nutritional Health and Nutrition Examination Survey conducted by department of Health and Human Services
88
What is the digestive system?
organ system primarily responsible for the movement of nutrients into the body proper
89
What are the organs of the digestive system?
gastrointestinal tract, four accessory organs (salivary glands, liver, gallbladder, pancrease)
90
How long is food left in the GI tract?
24-72 hours in a healthy adult
91
What are the four layers of the structure of the gut wall?
small intestine layers: mucosa, connective tissue, smooth muscle layers, outer connective tissue layer
92
How do digestive secretions help digest food?
mucus and enzymes: helps break down and absorb nutrients in the lumen of the GI tract
93
What kind of signals regulate digestive activity?
hormones and nervous signals
94
When does digestion begin?
cephalic phase: sight/smell of food, enters through mouth
95
Digestion in the mouth?
food broken into smaller pieces by teeth and mixed with saliva -- digest carbs with salivary amylase
96
Digestion in the pharynx?
passes through into esophagus; bolus of food swallowed, epiglottis pushed down over the trachea to prevent choking
97
Digestion in the esophagus?
peristalsis proels bolus to stomach; weight of bolus presses on lower esophageal sphincter (aka gastroesophageal sphincter and cardiac esophageal sphincter) to allow bolus into stomach
98
Digestion in the stomach?
temporary storage site for food; muscles mix into chyme; meal stays in stomach for 2-4 hours
99
How does the structure of the stomach support its function?
lining covered in gastric pits with gastric glands to produce gastric juice components
100
What is gastric juice?
water, mucus, HCl, pepsinogen (activated by HCl into pepsin)
101
How is stomach activity regulated?
amount/composition of food consumed and regulated by nervous and hormonal signals from stomach/small intestine
102
What is the small intestine's function?
main site of digestion and absorption of nutrients
103
How does the structure of the small intestine maximize function?
large circular folds, villi, microvilli, to increase absorptive surface area
104
How is chyme propelled through small intestine?
peristalsis, mixed by contractions of segmentation: bicarb from pancreas neutralizes stomach acid, pancreatic/intestinal enzymes digest macronutrients; aided by bile from gallbladder
105
How are nutrients absorbed in the small intestine?
across intestinal mucosa: simple diffusion, osmosis, facilitated diffusion do not require energy; active transport requires energy (down vs against concentration gradiet, respectively)
106
What does the large intestine do?
absorbs water and some nutrients, uses intestinal microflora (bacteria) to digest unabsorbed materials (fiber, etc.) to produce some nutrients and gas; remaining material excreted
107
How important is GI tract to health?
Very
108
What is the immune function of the GI tract?
immune system cells and tissues help eliminate disease-casuing organisms or toxins
109
How do immune response and food allergies interact?
if protein is absorbed whole (not broken to amino acids), likely to develop food allergy; common is seafood, peanuts, tree nuts, fish, soy, wheat, milk, and eggs
110
What is celiac disease?
protein gluten (wheat, barley, rye) triggers immune response that damages villi of small intestine: impairs absorption
111
What causes heartburn and GERD?
leakage of stomach contents into the esophagus
112
What causes peptic ulcers?
infections with Helicobacter pylori, GERd, of medications that damage mucosa
113
What is the consequences of gallstones?
interfere with fat digestion and absorption, pain
114
What causes diarrhea?
lining of small intestine inflamed, so impaired absorption
115
What causes constipation?
diet low in fiber, or high in fiber but low in fluids
116
How to provide nutrients to those who can't eat?
enteral feeding (tube through nasal passage into stomach; or intestine for liquid); total parenteral nutrition (delivers nutrients directly into bloodstream through vein in upper arm or chest)
117
How are nutrients delivered to body cells?
absorbed into mucosal cells of intestine, enter blodo circulation by hepatic portal circulation (water-soluble) or lymphatic system (fat-solbule)
118
Where do most of the absorbed nutrients go?
directly to liver through hepatic portal circulation
119
What is the function of the liver?
processing center, removing the absorbed substances for storage, converting them into other forms, or allowing them to pass unaltered
120
What is the function of the lymphatic system?
fat-soluble products of digestion absorbed; lipid transport particles absorbed into lacteals in intestinal villi, which feeds into lymph vessels -- enter blood circulation directly without first passing through liver
121
How do nutrients enter body cells?
through cell membrane receptors, etc.
122
What is the product of catabolism of glucose/FA/AA?
2-carbon acetyl-CoA; goes through TCA and generates CO2, water and ATP
123
What are some metabolic wastes?
carbon dioxide, nitrogen, water
124
What happens in the kidneys?
water and small molecules filtered out of blood through the nephrons; some filtered substances are reabsorbed, but the rest are excreted in urine
125
What is the difference between refined and unrefined grains?
whole grain has all three components (wheat, germ, endosperm), refined loses those phytonutrients in processing
126
What are enriched grains?
added iron, thiamin, riboflavin, niacin
127
What are fortified grains?
folate
128
What effect do added sugars have on nutrient density?
lowers it: less nutritional value
129
What are the three main elements in carbs?
carbon, hydrogen, oxygen
130
What are simple carbohydrates?
mono and disaccharides, found in table sugar, honey, milk
131
What are monosaccharides?
glucose, fructose, galactose
132
glucose?
blood sugar; primary form of carbs for energy
133
fructose?
fruit sugar; primary form of carbs in fruit
134
galactose?
combines with glucose to form lactose
135
What are the disaccharides?
maltose, sucrose, lactose
136
maltose?
two glucose molecules; formed during intestines during starch digestion
137
sucrose?
table sugar; fructose + glucose
138
lactose?
milk sugar; glucose + galactose; only naturally found in animal products
139
How are sugars made?
condensation reaction, releasing water molecule
140
How are sugars broken down?
hydrolysis, requires water molecule
141
What are some complex carbs?
oligosaccharides, glycogen, starches, fibers
142
What are oligosaccharides?
short-term carbs containing 3-10 sugar units, formed in gut during breakdown of polysaccharides
143
What is glycogen?
storage form of glucose in animals; highly-branched chain of glucose molecules that can be broken down quickly for energy; limited amount of glycogen stores in body; stored in liver and muscles
144
Where is glycogen stored and used for in those locations?
liver (for blood glucose) and muscles (for exercising muscles)
145
What are starches?
storage for of carbs in plants
146
What are fibers?
soluble vs insoluble; soluble = form viscous solutions, broken down in intestine by microflora: pectin/gums/hemicelluloses; insoluble = can't be broken down by bacteria: cellulose, lignin, some hemicellulose
147
What foods have fiber?
whole grains, legumes, fruits, vegetables
148
What happens to carbs in the digestive tract?
sugars and starches broken down into monosaccharides, absorbed in bloodstrea
149
How are carbs digested in the mouth?
salivary amylase to break starch into shorter polysaccharides
150
How are carbs digested in stomach?
salivary amylase inactivated by acid, so no carb digestion
151
How are carbs digested in small intestine?
pancreatic amylase completes job of breaking down starch into disaccharides and oligosaccharides; enzymes attached to microvilli complete digestion
152
How are carbs digested in large intestine?
fiber and other indigestible/resistance carbs partially broken down by bacteria to form short-chain FAs and gas
153
What is lactose intolerance?
undigested lactose passes into colon, draws in mater and is metabolize dby bacteria, produces gas and acids to cause abdominal distension, flatulence, cramping, diarrhea
154
How can lactose intolerant people get calcium?
tofu, fish, vegetables, calcium-fortified products, fermented dairy products
155
What are indigestible carbs and what happens to them?
fiber, some oligosaccharides, resistant starch: not broken down, so pass into colon
156
How do indigestible carbs affect transit time?
increase volume of material in lumen of intestine, adding bulk/weight to stool
157
What do indigestible carbs promote healthy microflora?
they're food for colon bacteria
158
Why do indigestible carbohydrates increase intenstinal gas?
oligosaccharides raffinose and stachyose usually culprits after consuming beans
159
How do indigestible carbs affect nutrient absorption?
fiber binds certain minerals (zinc, calcium, iron, magnesium) and prevent absorption; soluble fiber binds cholesterol/bile and reduces absorption; fiber causes distension in stomach and slows gastric emptying to increase satiation
160
What does fiber bind to prevent absorption?
zinc, magnesium, calcium, iron
161
What does soluble fiber bind to slow absorption?
cholesterol, bile
162
What is the main function of glucose?
provide energy to body cells
163
What are some other functions of carbs?
cell communication, synthesize DNA/RNA
164
How is glucose delivered to body cells?
monosaccharides travel to liver by hepatic portal vein; once in liver, Fruc/Galac converted into glucose and used in three ways: immediate energy, stoarge as glycogen, converted into FAs for long term storage
165
What are the three fates of fructose and galactose in the liver?
converted to glucose and then: 1) for immediate energy, 2) for storage as glycogen, 3) for fatty acids for long-term storage
166
What is glycemic response?
how quickly or how high blood glucose rises after carbs consumed
167
How is glycemic response quantified?
glycemic load or glycemic index
168
What hormones regulate glucose supply?
insulin and glucagon (in liver)
169
What do insulin and glucagon do?
insulin decreases blood glucose (uptake into muscle and adipose tissue); glucagon increases blood glucose (signals glycogen breakdown; from pancreas)
170
How does glucose provide energy?
metabolized to provide ATP through cellular respiration
171
What is glycolysis?
anaerobic metabolism; splits glucose into 2 pyruvates (3C each) in the cytosol; produces 2 ATP per glucose (1 per pyruvate)
172
How many ATP from glycolysis?
2 ATP per glucose
173
Where does glycolysis occur?
cytoplasm
174
What happes to pyruvate in presence of oxygen?
mitochondria: 1C removed and released as CO2, the other two mix with coezyme A to form acetyl-CoA for TCA
175
What happes in the TCA cycle?
acetyl-CoA enters and the 2 carbons are lost as carbon dioxide whereas the energy in bonds is used to make more ATP
176
What happens in the ETC?
the energy from high-energy electron inedmediates from TCA cycle and glycolysis is used to funnel electrons down a chain and pump H ions across the membrane to be used to make more ATP; electrons combine with hydrogen and oxygen to make water
177
What happens when carbs are limited?
metabolism shifts to ensure enough glucose; breaks down protein
178
What happens when protein is broken down?
skeletal muscle broken down to synthesize glucose through gluconeogensis
179
What are ketones?
molecules formed in liver when insufficient carbs to metaboliz the 2C units produced from fat breakdown
180
What is type 1 diabetes?
autoimmune disease: insulin-secreting pancreatic cells destroyed
181
What is type 2 diabetes?
body doesn't produce enough insulin to keep blood glucose in normal range; decreased insulin receptor function; higher levels of blood glucose; often preceded by prediabetes or impaired glucose tolerance
182
What is gestational diabetes?
occurs in women during pregnancy, disappears after birth
183
Why is diabetes problematic?
body can't use glucose correctly
184
What are imemdiate symptoms of diabetes?
excessive thirst, frequent urination, blurred vision, weight loss
185
What are long-term complications of diabetes?
damage to heart, blood vessels, kidneys, eyes, nerves: excessive blood levels of insulin and glucose
186
How to treat diabetes?
regulate blood glucose: diet, exercise, moderation
187
How can diet affect diabetes?
monitor carb food groups (vegetables, fruits, starches, dairy); not a low fat diet (since will increase blood levels of glucose and insulin); moderate in healthy fats
188
How can exercise affect diabetes?
increases sensitivty of body cells to insulin; glucose available to fuel exercising muscles as well as promoting weight loss
189
How can medication affect diabetes?
Type 1: inject insulin; Type 2: oral hypoglycemic agents taken
190
What is hypoglycemia?
blood sugar drops low enough to cause irritability, nervousness, sweating, shakiness, anxiety, rapid heartbeat, headache, hunger; common complication of diabetes treatment
191
What are dental caries?
most well-documented health problem associated with diet high in carbs = tooth cavities
192
How do cavities form?
baceteria form colonies and stick to teeth; metabolize carbs and produce acids that dissolve tooth enamel
193
Why do low-carb diets promote weight loss?
less food is consumed; ketosis occurs (suppresses appetite and food intake)
194
What is the consequence of ketosis?
suppresses appetite and reduced food intake
195
Why are high-carb diets linked to heart disease?
high carb diets increase blood lipid levels
196
How do indigetible carbs affect bowel health?
make stool larger and softer, to reduces pressure needed to move material through colon; lower risk of constipation, hemorrhoids, and symptoms of diverticular disease
197
How can fiber help protect against colon cancer?
cells in colon may be exposed to carcinogens in colon contents -- fiber may decrease amount of contact between cells of colon and carcinogenic substances
198
How much carbs should be eaten per day?
RDA for adults and children is 130g per day; 45-65% of energy from carbs; 25g fiber for females, 38g for males
199
What kinds of carbs are recommended?
unrefined, whole; limit added sugars to less than 10% of energy
200
What is the average american fiber intake?
only 15g per day, which is below the recommendation of 25-38g
201
What is the role of alternative sweeteners?
can reduce amount of added sugar; don't contribute to tooth decay, keep blood sugar in normal range; reduce energy content of diet if calories they eliminate aren't added back in other food choices
202
What are nonnutritive sweeteners?
alternative sweeteners that provide no calories: saccharin, aspartame, sucralose, acesulfame K, rebiana
203
What are sugar alcohols?
sweeteners that are structurally related to sugars, but provide less energy because aren't well-absorbed; can cause digestive issues because produce gas
204
What do fats do for food?
add desirable texture and taste
205
How many kcal/g fot fats vs carbs/protein?
9 for fats, 4 for carbs/protein
206
What is the chemical makeup of lipids?
organic, not water soluble, hydrophobic
207
What are the types of lipids?
fatty acids, triglycerides, sterols, phospholipids
208
What are whole food/natural sources of lipids?
nuts, meats, whole fat dairy, avocados, oils/butter
209
What counts more for health, overall dietary patterns or total fat intake?
overall dietary patterns: depends on how many kcals taken in, not just fat (so if you cut fat but increase calories elsewhere, won't help)
210
What are fatty acids?
chains of C,H, O: one end has methyl group (omega end)
211
What are triglycerides?
3 fatty acids in ester linkage to glycerol; fats found in food and form of lipid that provides energy
212
What is the form of lipid found in food and used for energy in the body?
triglycerides
213
What are phospholipids?
structural; made of 2 Fas with a polar head for membranes; contain phosphorous
214
What are sterols?
not built of fatty acids; cholesterol, some hormones, etc.
215
What is the omega end of a fatty acid?
methyl end: carbon bound to three hydrogens
216
What is opposite the omega end of a fatty acid?
carboxyl end: -COOH group
217
What determines fatty acid structure and function?
chain length and # of double bonds
218
Which lipid type can directly enter cells and be catabolized to make ATP?
fatty acids
219
How are fatty acids stored in the body?
as triglycerides: found in adipocytes
220
What is glycerol?
backbone for TG; composed of 3C and some H and O
221
What are the three general categories of fatty acid?
short chain (4-7) medium chain (8-12) and long chain (13-20)
222
Give examples of all three chain lengths of fatty acids
short = milk fat; medium = coconut oil; long = beef fat
223
What is saturation?
description of # and type of double bonds in a fatty acid
224
What is a saturated fatty acid?
no double bonds anywhere
225
What are the health implications of saturated fatty acids?
increased risk of heart disease
226
what food sources have saturated fat?
animal fats, tropical plant oils (coconut, palm, palm kernel); most sources of fat have at least some saturated fatty acids on the TG
227
What are the most common saturated fats?
stearic (18C) and palmitic (16C)
228
What is the physical state of the different lengths of fatty acid chains?
short = liquid when cold and RT; medium = solid when cold, liquid at RT; long = solid when cold and RT
229
what kind of fats are susceptible to oxidation?
unsaturated (saturated fats do not oxidize as readily)
230
What happens when a fat oxidizes?
smells rancid, carcinogenic properties
231
What kind of fat has a longer shelf life?
saturated: less readily oxidized
232
What are unsaturated fats?
contain at least one double bond between carbons; tend to be liquid at RT
233
What's the relationship between unsaturation and physical state at RT?
the more unsaturated, the more likely to be liquid at RT (and the lower the melting temperature)
234
Most common monounsaturated fatty acid?
oleic acid (primary FA in olive oil)
235
Most common polyunsaturated polyunsaturated fatty acid?
linoleic acid (in a lot of plant oils)
236
What are the health implications of unsaturated fatty acids?
decrease risk of heart disease
237
What are essential fatty acids?
Omega-3 and Omega-6; we can't make them in the body, so must obtain from diet
238
What are Omega-3 Fas?
first doulbe bond between 3-4 C from omega end upward
239
What are three examples of Omega-3 FAs?
ALA (alpha-linolenic; primary in plants); EPA (eicosapentanoic acid); DHA (docosapentanoic acid) from animal sources like fish
240
Which forms of Omega-3 have health benefits and why?
EPA and DHA: body can convert those, but not ALA
241
What are Omega-6 FAs?
first double bond between 6-7 C from omega end upward; includes linolenic acid (plant seed oils) and arachidonic acid (from animal fats, red meat)
242
What are two examples of Omega-6 FAs?
linolenic acid (plant seed oils), arachidonic acid (red meat)
243
What are the roles of Omega-3 and Omega-6 fatty acids?
make eicosanoids (regulatory compounds with hormone-like function that work in same location as made)
244
What are eicosanoids?
hormone-like regulators that are synthesized and utilized in the same location
245
What is important about the relationship between Omega-3 and Omega-6 fatty acids in the body?
need the ratio to be favorable; want more Omega-3 than Omega-6)
246
What is the tradeoff/paradox for Omega-3 and Omega-6 fatty acids?
can have favorable eicosanoid benefits, but since they are unsaturated, they will oxidize in the body and contribute to chronic disease risk
247
What substance is energy-yielding without being considered a food?
alcohol: you don't gain weight the same way
248
What is the function of phytonutrients in plants?
to protect the plant from damage (UV, herbicides, pesticides, predators, etc.)
249
Wow can you get more phytonutrients in a plant?
when you damage it: consider health benefits of wine from crushed grapes; olives stressed to produce healthier olive oil
250
Hhow is extra protein stored by the body?
as fat, not muscle
251
how much of the human body is water?
approximately 60%: high muscle content needs more water, higher fat content needs less water)
252
What is the function of nutrients?
provide energy: for biochemical reactions in the cody and to fuel physical work
253
What are four methods of assessing nutritiaonl health/intake?
24-hour recall; food diary/food intake record; food frequency questionnaire; diet history
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What are the four stages of nutritional deficiency?
Inadequate intake; Decreased stores/tissue levels; Altered biochemical and physiological function; Physical signs and symptoms of deficiency
255
How do we assess the US population for health and diet?
NHANES study: now online, continual survey asking about intake habits, nutrition-related interview, etc.
256
What is the function of lysozymes in digestion?
help to inhibit bacterial growth in the mouth
257
What gets absorbed in the stomach?
Water, salt, alcohol
258
Where does 95% of digestion occur?
Small intestine
259
What does the gallbladder do?
stores and releases bile (produced by the liver) to emulsify fat to ease absorption
260
What does the pancreas do?
secretes digestive enzymes, bicarbonate ions to raise pH from stomach acid HCl
c
261
Give examples of substances that are absorbed by the three types of transport.
Passive (water, some fats, some minerals), Facilitative (fructose); Active (carbs, AA)
262
Which is better, probiotics or prebiotics?
Prebiotics: not digested by small intestines, but will stimulate growth/activity in colon bacteria (onions, garlic, bananas, artichokes, etc.)
263
What reuslts in ketone production?
Incomplete fat catabolism, because there's not enough glucose to fuel it through to the end
264
Ketones are short-term energy usage for what organs?
Brain, heart
265
What type of diabetes is the one you get when you're older?
Type 2
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What are carbs that have ten or fewer monosaccharides? Where are they found
Oligosaccharides; found in legumes
