NTR 306 Midterm: Nutrition-EXAM2STUDYGUIDE
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Exam 2 Review
All Topics (Lipids, Proteins, Metabolism, Energy Balance & Wt Mgmt)
Definitions to Know
· essential fatty acid- Linolenic 18:3 (omega 3) and Linoleic 18:2 (omega 6)
· AMDRs and kilocalorie densities (for CHO, lipids, protein)
● fat 20-35%, 9kcal/g
● protein 10-35%, 4 kcal/g
● CHO 45-65%, 4 kcal/g
· linolenic acid - polyunsaturated fatty acid, 18 carbon chain, 3 double bonds, omega 3; linoleic acid
- polyunsaturated fatty acid, 18 carbon chain, 2 double bonds, omega 6
· SFA - butyric, MUFA - oleic; one double bond, PUFA - linoleic omega- 6/linolenic omega - 3;
2 double bonds, HUFA - more than 2 double bonds
· Cis fatty acids - double bond and hydrogens on the same side, bends into a U-shape, naturally
occurring; trans fatty acids (TFAs) - double bond and hydrogens on opposite sides, linear shape, TFAs
act like a SFA in the body, makes liquid fats more solid, occurs during exposure high temperatures like in
processed foods or fried food
· Partially-hydrogenated fatty acids (PHVO) - improve texture in foods (ex: margarine more
spreadable), protects against oxidization/food spoilage, occurs during food processing
· triglyceride - glycerol (a 3C chain) combines with 3 fatty acids, formed during condensation
· phospholipid- Water loving head and water hating tail. Form a lipid bilayer membrane of cells. Made
of glycerol, choline, and fatty acid. Function is to emulsify fat and helps send signals between cells. Lecithin
is most well-known phospholipid. Sources: eggs, soy, liver, peanuts
· sterol; cholesterol- bile acids (absorb fats), estrogen, testosterone, Vitamin D.
· plant stanols-structural similarities to cholesterol. lower blood cholesterol by interfering with
absorption
· hydrolysis and condensation (as they relate to lipids and proteins)
· peroxidation of lipids: oxygen attacks double bonds in fats making them rancid
· arteriosclerosis, atherosclerosis - accumulation of plaque in arteries caused by high cholesterol
levels, causes CHD and ischemic strokes
· stroke (cerebrovascular disease complication): hemorrhagic- 13% of all stroke cases, blood
vessel in brain ruptures (aneurysm) vs. ischemic- more common, blood flow to brain is blocked, caused by
atherosclerosis
· VLDL, LDL, IDL, HDL, chylomicron, lipoprotein
●-Chylomicron- first lipid carrying protein. Transport diet derived lipids (Triglycerides) from the small
intestine to rest of body. largest/least dense; diet-derived lipids from small intestine to the rest of the
body
●HDL- Picks up cholesterol not being used so it can be recycled.
●VLDL (very low density lipoprotein)- Lipids made in the liver that are packaged with proteins and
then is carried by Chylomicron. As it travels through the body triglycerides are removed and it
becomes LDL.
●LDL- Carry cholesterol.
●lipoprotein - clusters of lipids and proteins that serve as transport vehicles for lipids
· Receptor-mediated endocytosis
● (process where cells take in LDL???)
· hypercholesterolemia
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● A genetic disease where there is normal blood pressure and no diabetes but there is excessive
cholesterol in the blood. (failure to produce functional LDL receptors)
· HMG CoA reductase
●An enzyme that produces cholesterol.
· statins
●A drug that limits the enzyme HMG CoA from making cholesterol.
· transcription - process that makes RNA;
translation - process that makes proteins
· limiting amino acid - the essential amino acid found in the shortest supply relative to the amounts
needed for protein synthesis in the body that human beings require; four amino acids are most likely to be
limiting: lysine (most limiting in cereal protein), methionine (most limiting in legumes), threonine, and
tryptophan
· transamination - transfer of an amino group from one amino acid to a keto acid, producing a new
nonessential amino acid and a new keto acid.
· gluconeogenic amino acids; ketogenic amino acids
· deamination- Removal of the amino (NH2) group from an amino acid. produces ammonia and a keto
acid.
· gluconeogenesis;
Creation of glucose from noncarbohydrate sources.
ketogenesis/ - the process by which ketone bodies are produced as a result of fatty acid breakdown.
ketone bodies/ - are three water-soluble, biochemicals that are produced by the liver from fatty acids during
periods of low food intake or carbohydrate restriction for cells of the body to use as energy instead of
glucose.
When there is not enough glucose available fat is used for energy and those fragments of fat form ketone
bodies.
ketosis forming ketone bodies
· metabolism; anabolism; catabolism
· Metabolism: the sum total of all the chemical reactions that go in living cells. Energy metabolism
includes all the reactions by which the body obtains and expends the energy from food
· Anabolism: reactions in which small molecules are put together to build larger ones. Anabolic reactions
require energy
· Catabolism: reactions in which large molecules are broken down to smaller ones. Catabolic reactions
release energy
· anaerobic, aerobic respiration
· ATP · ATP: adenosine triphosphate- a common high energy compound composed of a
purine, a sugar, and three phosphate groups
· "healthy," underweight, overweight, obese BMI; BMI formula
● 18.5 - 24.9 healthy weight
● 25 - 29.9 overweight
● > 30 obese
● <18.5 underweight
● <16 may indicate eating disorder or disease
● BMI=wt(kg)/ht^2 (in meters)
· bomb calorimeter - A bomb calorimeter is a type of constant-volume calorimeter used in measuring
the heat of combustion of a particular reaction.
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· direct calorimetry; measures amount of heat released
indirect calorimetry; measures amount of oxygen consumed
· basal metabolic rate (BMR): amount of energy that you have to expend when you are totally at rest
and you haven’t eaten; 2/3 energy outputs
· visceral adipose/fat: fat surrounding the organs
· estimated energy requirement (EER)
· thermic effect of food (TEF): energy used to process food; 10% of energy (free calorie burning)
· adaptive thermogenesis: Production of heat in response to environmental changes and diet,
resulting in metabolic inefficiency
· Non-Exercise Activity Thermogenesis (NEAT): physical activity that you do that can range
anywere from 200-800 kcals a day (sitting up straighter, fidgeting)
· obesity: deposition of excess fat in the body
· endomorphic body build; (soft, round body build w/ high proportion of fat tissue)
ectomorphic body build; (lean/delicate body build)
· "thrifty genotype"; store more fat (previously good during famine)
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· CNS= central nervous system: includes brain and spinal cord, controls appetite and fat storage
· hypertrophy vs. hyperplasty (e.g. in fat cells)
● hypertorphy- increase in size of cells
○ associated with weight in adults
● Hyperplasty- increase in number of cells
○ associated with weight in children and adolescents
Lipids
· Recommendations/Sources
· What are our benchmarks for lipids? What recommendations does the Dietary Guidelines for
Americans 2010 make related to lipids?
● Reduce the amount of solid fat consumed. Instead consume oils. 20-35% of energy intake be from
fat, less than 10% from saturated fats, as little trans fat as possible, and less than 300 mg of
cholesterol
· What are the major sources of saturated fats in the American diet? Of transfats? Where does
cholesterol come from in the diet? Saturated fats: whole milk, cream, butter, cheese, ice cream, fatty
cuts of beef and pork, coconut, palm, palm kernel oil Trans Fats: cakes, cookies, doughnuts, pastry,
crackers, margarine, deep-fried foods, chips Cholesterol: meats, eggs, seafood, poultry, dairy
· How can we cut down on fat and/or cholesterol in the diet? What foods are high in cholesterol?
●Use fat replacers – ingredients that replace some or all of the functions of fat and may or
may not provide energy
●Use artificial fats – zero energy fat replacers that are chemically synthesized to mimic the
sensory and cooking qualities of naturally occurring fats but are totally or partially
resistant to digestion
○Olestra – synthetic fat made from sucrose and fatty acids that provides 0 kcal/g
· What foods contain PHVOs?
● Processed foods that were originally liquid at room temperature, but become solid when
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Document Summary
All topics (lipids, proteins, metabolism, energy balance & wt mgmt) Essential fatty acid - linolenic 18:3 (omega 3) and linoleic 18:2 (omega 6) Amdrs and kilocalorie densities (for cho, lipids, protein) fat 20-35%, 9kcal/g protein 10-35%, 4 kcal/g. Linolenic acid - polyunsaturated fatty acid, 18 carbon chain, 3 double bonds, omega 3 ; linoleic acid. Polyunsaturated fatty acid, 18 carbon chain, 2 double bonds, omega 6. Sfa - butyric, mufa - oleic; one double bond, pufa - linoleic omega- 6/linolenic omega - 3; 2 double bonds, hufa - more than 2 double bonds. Partially-hydrogenated fatty acids (phvo) - improve texture in foods (ex: margarine more spreadable), protects against oxidization/food spoilage, occurs during food processing. Triglyceride - glycerol (a 3c chain) combines with 3 fatty acids, formed during condensation. Phospholipid - water loving head and water hating tail. Function is to emulsify fat and helps send signals between cells. Sterol; cholesterol - bile acids (absorb fats), estrogen, testosterone, vitamin d.
