Exam 2 Flashcards
How many kcals per gram to fats have?
9
What % of the typical american diet is from fat?
34%
What are triglycerides?
3 Fatty acids attached to a glycerol molecule
What is the major form of lipid in food and body?
Triglycerides
Short Chain Fatty Acids
Range from 4-7 carbons
remain liquid at cooler temperatures
ex. Milk
Medium Chain fatty acids
8-12 carbons long
Solidify when chilled, but liquid at room temperature
ex. Coconut Oil
Long Chain fatty acids
greater than 12 carbons
Solid at room temperature
Beef fat
Saturated Fatty Acids
Contain carbons in a chain that are bound to two hydogens (no double bonds)
- Most animal fats, palm oil and coconut oil
- less susceptible to spoilage
Unsaturated Fatty Acids
- Contain some double bonds
- Can be monounsaturated or Polyunsaturated
Monounsaturated fatty acid examples
olive oil, avocado– have one double bond
Polyunsaturated fatty acid examples
- Omega 3
- –ALA (flax, canola oil, nuts)
- –EPA, DHA “Long Chain” (fish)
- Omega 6 (Linoleic Acid, Corn, Safflower oil, nuts
Cis Bonds
results in bent chains
Trans fatty acids
occur naturally in small amounts, but most are created by hydrogenation
- results in straight chains
- lengthens the shelf life
Trans Fatty Acid food sources
Shortening, Margerine, Biscuit, Chocolate Chip Cookies
Phospholipids
lipids attached to a phosphate group
Phosphoglycerides
1 FA attached to a glyceride backbone
ec. lecithin
Can act as emulsifiers– allow oil and H20 to mix
Form a lipid bilayer in call membranes that regulate what can pass into and out of a cell
Sterols
type of lipid found in plants and animal- has a multiple ring structure
Do not dissolve well in water
Cholesterol
a type of sterol found only in animals
- the liver can manufactore all needed cholesterol, so it is not needed in the diet
- 90% of cholesterol in the body is found in cell membranes
- is needed to synthesize vitamin D and steroid hormones
Food Sources of Cholesterol
Online animal products
- eggs
- beef liver
Lipid digestion
-Small amount in mouth due to gastric lipase produced in the stomach
-liver produces bile, stored in gall bladder and released in SI
-Pancrease produces pancreatic lipase-released inSI to break down triglycerides
Short/medium chain trig. are water soluble, can be aborbed into bloodstream
-In SI products of fat digestion and bile acids form into micelles which diffuse out into mucosal cells
-in mucosal cells fatty acids and monoglycerides are reassembled into triglcerids, form into chylomicrons and enter lymph
-Very efficient, very little fat is lost in feces
Lipoproteins
Combination of water insoluble lipids, phospholipids and proteins, act as a transport vehicle
-help to transport triglycerides, cholesterol and fat soluble vitamins from the SI and stored lipids from the liver
Chylomicrons
combination of diet derived triglycerids, cholesterol, phospholipids and a small amount of protein
Help transport long-chain fatty acids into the lymphatic system and into the blood stream without passing through the liver
-Deliver triglycerids to the body cells
Lipid transport and delivery
- Chylomicron formed in mucosal cells pass into lymph, which drains into the blood, they circulate in the blood delivering triglycerides to body cells
- Lipoprotein lipase breaks down triglycerides in chylomicrons into fatty acids and glycerol which can then enter the surrounding cells
- Remaining chylomicron parts are removed to the liver to be disassembled
- VLDLs are made in the liver and transport lipids away from the liver to body cells
5IDL particles that remain after the triglycerides are removed are returned to the liver, or transformed in the blood into LDL particles - To deliver cholesterol, LDL particles bind to LDLreceptors in the cell membrane, this allows the LDL to enter the cell whre cholesterol and other components can be used
7.HDL particles pick up cholesterol from other lipoproteins and body cells and return it to the liver, some is broken down, some is transferred to organs that synthesize hormones
Chylomicron
- largest lipoproteins and contain the greatest proportion of triglycerids
- form in mucosal cells, pass into lymph, then into blood stream
- deliver triglycerides to the body cells
VLDL
- smaller than chylomirons
- contain a high proportion of truglycerides
- made in liver
- transport lipids away from the liver
- deliver triglycerids to body cells wi/ help of lipoprotein lipase which removes triglycerides from VLDLs making IDLs
LDL
Contain higher proportion of cholesterol than other lipoproteins, and less triglycerides
Made in blood from IDLs
Deliver cholesterol by binding to LDL receptors in the cl membrance
High levels of LDLs in the blood are associated with an increased risk for heart disease
HDL
high in cholesterol and are the densest lipoproteins due to their high protein content
- pick up cholesterol from other lipoproteins and body cells and return it to the liver
- prevent cholesterol from depositing in the artery walls
- high levels of HDL are associated with a reduction in heart disease risk
What is the major lipid producing organ in the body?
Liver
Can make triglycerides from excess protein and carbohydrates
lipoprotein lipase
removes triglycerids from VLDLs creating intermediate density IDLs
adipose tissue
store triglycerides
define body shape, provide stored energy, insulate body from temp changes, and protect internal organs against physical shock
Use of lipids in body
lubricate body surfaces, such as the mucous membranes of the eyes
Cholesterol uses
used to make several hormones, including sex hormones and cortisol
Polyunsaturated fatty acid uses
help regulate blood pressure and blood clotting
Essential Fatty Acids
have to be consumed in the diet
-important for growth, skin integrity, fertility, and the structure and function of cell membranes
Eicosanoids
made from omega 3 and omega 6 fatty acids
help regulate blood clotting, blood pressure and immune function
Essential fatty acid deficiency symptoms
dry and scaly skin, liver abnormalities, poor wound healing, growth failure in infants, impaired hearing and vision
Omega 6 derived eicosanoids
increase inflammation, increase blood clotting, increase blood pressue
Omega 3 derived eicosanoids
decrease inflammation, decrease blood clotting and decrease blood pressure
sources of omega 6/linoleic acids
vegetable oils and meats
sources of omega 3/ alpha linolenic acid
flaxseed, walnuts, soy
Energy from triglycerides
fatty acids and glycerol can be used to produce energy in the form of ATP (glycerol foes in as glucose or pyruvate… fatty acids go in as acetyl CoA)
Beta oxidation of fatty acids begins the metabolic pathway to produce ATP
Feasting
When excess energy is consumed it is stored as triglycerides in adipose tissue
Fasting
When no food has been eaten for a while, triglycerides from adipose tissue are broken down, releasing fatty acids as an energy source
Atherosclerosis
a disease in which lipids and fibrous materials are deposited in artery walls— if clot goes to the brain it’s a stroke, if it goes to the heart it is a heart attack
Age as a risk factor for heart disease
-non modifiable
as age increases (men over 45, women over 55) risk increases
-almost half of people with cardiovascular disease are 60 or older
Gender as a risk factor for heart disease
men @ risk at a younger age
-estrogen acts as protection
Genetic Background as a risk factor for heart disease
if a male family member had it before 55, or a female had it before
Blood pressure as a risk factor for heart disease
high blood pressure > 140/90 can damage blood vessel walls, causing heart to work harder
Diabetesas a risk factor for heart disease
blood glucose >126/100 damages blood walls
obesity as a risk factor for heart disease
increases blood pressure, cholesterrol, diabetes, increases the amount of work the heart needs to do to pump blood through the body
blood lipid levels as a risk factor for heart disease
cholesterol >200
LDL>130
HDL<40
mean you are at high risk
smoking as a risk factor for heart disease
increases risk
activity as a risk factor for heart disease
regular exercise decreases risk
Dietary factor to reduce heart risk
- whole foods
- polyunsaturated and monounsaturated fats
- plant foods, b vitamins, antioxidants
- moderate alcohol consumption
- fiber (binds cholesterol so you absorb less)
Dietary factors that increase heart risk
cholesterol saturated fat (increased LDL) Transfat (increase LDL, decreased HDL) Sodium (increased blood pressue) Excess sugar (increased circulating triglycerides) Excess energy (obesity)
Red meat and colon cancer
diets high in red meat are associated with higher incidence of colon cancer
AMDR for fat
20-35% total kcal (for >19, varies based on life stage)
What are there AIs for in Fats
AI, ALA
2010 Dietaey guidelines for fat
- limit intake of solid fats
- encourage fat from liquid oils, nuts, fish
AMDR for fat: pregnant women
AMDR for fat not increased
AI for essential fatty acids are slightly higher
Infant Fat intake
Infants need a diet with 40-55% energy as fat
Ages 1-3 fat intake
30-40% of energy intake
ages 4-18 fat intake
25-35%
Elderly fat intake
Same as young, 20-35%
fat free
less than 0.5g of fat per serving
low fat
3g or less of fat per serving
reduced or less fat
25% less fat per serving than the regular product
saturated fat free
less than 0.5 g saturated fat
low saturated fat
1g or less of saturate fat, not more than 15% of calories from saturated fat per serving
reduced or less saturated fat
at least 25% less saturated fat than reference product
cholesterol free
less than 2mg of cholesterol
reduced or less cholesterol
contains at least 25% less cholesterol than regular product
lean
less than 10g of fat, 4.5 g or less of saturated fat, less than 95mg of cholesterol per 100g
extra lean
contains less than 5g of fat, less than 2g of saturated fat and less than 95mg of cholesterol per serving and per 100g
problems with olestra
is a fat based substitute that can reduce the absorption of fat-soluble vitamins, can cause GI problems
How much cholesterol in an egg?
200mg
What does an egg give?
6g PRO, Vit A, Vit D, 200mg cholesterol
Egg consumption
1 egg/day did not result in an increased cardiovascular risk , except for those with diabetes
Dietary Guidelines for eggs and cholesterol
1 egg a day is OK, Limit dietary cholesterol to <300mg daily
Coconut oil
-mostly saturated fat, medium length chains
transported via the liver
Where do the calories in alcohol come from?
Carbohydrates and alochol
Definition of a drink
5oz wine, 12oz beer, 1.5 oz spirits
Alcohol absorption
- is rapidly absorbed by simple diffusion along the entire GI tract
- 20% is absorbed in the stomach
- abosorbed alcohol is rapidly distributed throughout all body water compartments
- 90% of alcohol is metabolized by liver, 5% is excreted into the urine, and the remainder is elimated via the lungs
Weight and BAC
higher weight, more body water, dilute alcohol content
Gender and BAC
men have more body water and alcohol dehydrogenase, so lower alcohol levels
Food and BAC
food in stomach slows alcohol absorption, so lowers alcohol levels
Alcohol Dehydrogenase
Primarily found in liver, stomach, works for small amount of alcohol
Microsomal ethanol oxidizing system
found in liver, used when larger amounts of alcohol are consumed. needs energy and O2
Allcohol metabolism for small amouts
ADH breaks down alcohol to produce acetaldehyde, decreated to acetyl coa, the breakdown of alcohol and acetaldehyde releases electrons that can be used to produce ATP, but also results in inhibition of the citric acid cycle, limiting breatdown, so leads to fat build up
Alcohol metabolism large amounts
MEOS activity increases, converting alcohol into acetaldehyde which is broken down to acetyl coa, can’t enter the citric acid cycle because it is inhibited, instead it forms fatty acids which accumulate in the liver andform fatty liver
short term effects of alcohol consumption
interfere with organ function several hours after ingestion, reasoning, vision, speech
effects of chronic alcohol consumption
interferes with nutritional status, produces toxic compounds, inreases cancer risk
Liver damage: fatty liver, alcoholic hepatitus, cirrosis
Hypertension, heart disease and stroke,
how does excessive alcohol consumption cause malnutrition?
decreases overall nutrient intake, interferes with nutrient absorption, storage, metabolism and excretion, increases kcal intake
Chronic alcohol use and birth defects
increases the risk of fetal alcohol spectrum disorders, including fetal alcohol syndrome when consumed during pregnancy
Chronic alcohol use and gastrointestinal problems
damages the lining of the stomach, small intesting an contributes to development of pancreatitis
Chronic alcohol use and liver disease
causes fatty liver, alcohol hepatitus and cirrhosis
Chronic alcohol use and malutrtion
decreases alcohol absorption and alters the storage, metabolism, and excretion of som vitamins and minerals
Chronic alcohol use and cardiovascular disorders
associated with cardiomyopathy, hypertension, arrhythmias and stroke
Chronic alcohol use and cancer
increases risk of cancers of upper digestive tract, including the esophahus, mouth, pharync and larynx as well as the liver, pancreas, breast and cancer
Chronic alcohol use and pshychological disturbances
causes depression, anxiety and insomnia and is associated with higher incidence of suicide`
Impact of moderate alcohol consumption on the cardiovascular system
increase HDl, decrease LDL, decrease clotting, decrease homocysteine, decrease cell aggregation, beneficial for cardiovascular health
impact of excessive alcohol consumption on cardiovascular system
increase acetaldehyde, increase oxidative stress, increase triglycerides, decrease HDL
increase reactive species, increase cell aggregation
Relationship between economy and protein
As a countries economy improves, the proportion of animal foods in the diet tends to increase
Amino acids
Are the building blocks of protein. Each amino acid contains a central carbon atom bound to a hydrogen atom, an amino group an acid group and a sidechain
peptide bonds
chemical bonds that link amino acids together. Are formed between the acid group of one amino acid and the nitrogen group of the next amino acid
Dipeptide bonds
formed between two amino acids
polypeptides
formed between many amino acids
protein
one or more polypeptide chains folded into a three dimensional shape
Protein shape determine function
conective tissue proteins and collagen are elongated
hemoglobin is spherical
if shape is altered, function will be disrupted
protein digestion and absorption
- chewing begins breakdown
- HCl in stomach and pepsin start to break down protein
- In SI, protein digesting enzymes secreted from the pancrease and those in the microvilli break down polypeprides into amino acids, dipeptides and tripeptides
- Transport proteins move the products into the mucosal cell
- Dipeptides and tripeptides can enter the mucosal cell, once inside they are broken down into single amino acids
- AA pass into the blood and travel to the level
8 common allergens
milk, eggs, nuts, wheat, soy, fish, shellfish and fish, peanuts
anaphylaxis
a rapid sever allergic reaction
what triggers food allergies?
when a protein from the diet is absorbed without being completely digested
GI disease and allergies
people with GI disease are prone to allergies because their damaged intestines allow for the absorptio of whole proteins
uses of AA pool
energy, synthesis of glucose or fatty acids, synthesis of nonprotein molecules that contain nitrogen
limiting AA
a shortage of an amino acid can limit the bodies ability to synthesize a protein that uses that amino acid
AA metabolism
- amino group is removed by deamination
- deamination of some glucogenic AA produes 3 carbo molecules that can be synthesized to make glucose
- Deamination of ketogeninc AA makes acetly CoA
- Deamination of so glucogenic AA form intermediates in the citric acid cycle that can be used to synthesize glucose
- high energy electrons from the breakdown of amino acids are transferred to the ETC and used to make energy
- Amino group produces ammonia which is toxic, it is combied with CO2 to form urea
Protein Energy Malnutrion
a broad range of protein deficiency conditions that may include only a protein deficiency or a protein deficiency plus energy deficiecy
Kwashiorkor
pure protein deficiecy
-swollen belly
Marasmus
energy and protein deficiency
depletion of fat stores and wasting of muscle
effects of elevated protein intakes over long periods
-hydration and kidney issues
bone health issues
kidney stones
increased risk of heart disease and cancer
Phenylketonuria
PKU
is an inherited condition attributed to a defective gene
in aspartame
blocks change of phenylalanae to tyrosine
Phenyalanine metabolism
Phenylalanine is usually converted to tyrosine, with PKU that is blocked and phenylalanine becomes phenylketones
Monosodium glutamate
MSG
consists of glutamic acid bound to sodium
Can cause flushed face, tingling or burning, headache, rapid heartbeak, general weakness
Nitrogen balance
In=out
Total body protein does not change
Negative nitrogen
balance in<out
total body protein decreases
due to injury or illness as well as lack of protein or energy in the diet
positive nitrogen balance
in>out
total body protein increases
when body is growing, pregnancy, body builders
Protein requirements
0.8g/kg
AMDR for protein
10-35 for adults
needs to increase during periods of grouwn, pregnancy and lactation and healing
protein need sin pregnancy
25gprotein/day ABOVE the reccommendationfor pregnant and breastfeeding women
Protein needs in infants
For the first 6 months: 1.52g/kg of body weight
2nd 6 months: 1.5g/kg body weight
Protein needs for children
Ages 1-3: 5-20% of caloires
age 4-18, 30%
PDCAAS
Protei digestability corrected amino acid source
Basically says that animal proteins are of ahigher quality
a measure of protein quality that reflects a proteins digestability as well as the proportions of amino acids it provides
Biologival value
a measure of protein quality determine by comparing the amount of nitrogen retained int he body with the amount absorbed from the diet
Why are we eating more?
appetite v. hunger, food environement, portion distortion, less energy expenditure due to screen time
energy balance
when energy consumed equals energy expenditure
kilocalories
a measure of the amount of energy that is supplied to or expended by the body
Bomb calorimeter
food is burned in chamber
1kcal is the amount of heat to increase the temperature of 1kg of water by 1 degree C
slightly overestimates the amount of energy which can be utilized by the body
Converting food energy into ATP
1Glycolysis breaks glucose into 2 pyruvates which are converted to acetyl co a
2 B oxidation breaks fatty acids into 2 carbon units that form acetyl coA
3. after deamination AA can break down to fform acetyl coA, pyruvate
4. acetyl Coa can enter the citric acid cycle
5. th electrons released are passed to the ETC where energy is used to make ATP
TEE
total energy expenditure
all energy used for basal metabolism, activity, processing food, deposition of tissue and production of milk
=BEE+PA+TEF
what it takes to fuel the body
BEE
basal energy expenditure
energy expended to maintain an awake resting body that is not digesting food
all the basic functions, heart, lungs, kidneys etc
BMR
basal metabolic rate
rate of energu expenditure under resting conditions
resting in awarn room after fasting for 12 hours
REE
resting energy expenditure
estimates basal metabolim
higher than basal, test is after 5 hours of rest
includes involuntary functions
RMR
resting metabolic rate
NEAT
non exercise activity thermogenesis
TEF t
thermic effect of food or diet induced thermogenesis– cost of processing macronutrients
energy required for the digestion of food and the absorption metabolism and stoeage of nutrients
is about 10% intake
Sources of staored energy in the body, glycogen
1400
Sources of staored energy in the body,glucose or lipid
100
Sources of staored energy in the body,Triglyceride (adipose tissue)
115,00 kcals
Sources of staored energy in the body, protein
25000
Storing energy as fat
Glucose–>pyruvate–>acetyl coa–>fatty acids–>triglycerids for storage
Amino acids–>acetyl co a–>fatty acids–>riglycerids for storage
fatty acids–>riglycerids for storage
Direct calorimetry
-measures heat produced to determine energy used
requires an insulated chamber- is not practical
Indirect calorimetry
measures O2 utilization/CO2 production
More practical, but requires bulky equiptment
is the gold standard for measuring energy requirement
Doubly labeled water
-track exretion of labeled o2/h2 to determine the amount of CO2 produced
How to estimate EER
determine physical activity value
choose equation based on gender and age
find height in m
find weight in kg
How to determine physical activity value
intensity of activity
time spent doing the activity
age
gender
excess body weight and disease risk
sleep apnea, fatty liver, gallbladder disease, type 2 diabetes, GERD, cardiovascular disease
BMI equation
weight in kg/(height i m)^2
BMI ranges
Underweight 30
Morbidly obese 40
Body fat in pregnancy
increase in body fat percentage to provide energy for fetus and lactation
Body fat in in infants
at birth 12%, this percentage increases in the first year of life
Body fat in childhood and adolescents
as muscle mass increases, percent body fat decreases. During puberty females gain more fat and men gain more muscle
Body fat in elderly
lean body mass decreases between ages 20-60, body fat typicallt doubles
Bioelectric impedance analysis
tool to asses body composition
is handheld-like at gym or in scales
uses electrical current
lean tissue (is high in water) and conducts electricity, fat does not
Skinfold thickness
tool to asses body composition
assumes fat under skin represents total body fat
inexpensive, have at gyms, must be well trained
underwater weighing
tool to asses body composition
weight on land vs. weight in water determines volume/density
lean tissue is more dense than fat
Waist circumference and disease risk
Women >35in and men >40 in are at a higher risk for disease
Factors in determining body shape and size
75% genetics
25% lifestyle
Set point
level at which body weight resists change- may increase over time
short term regulation of energy balance
regulating intake from meal to meal
-nerbes hormones
psychologival distress can alter mechanisms
ghrelin
in stomach, makes us want to eat at certain times
CCK
slows down stomach emptying, gives a feeling of satiety
Longterm regulaion of energy balance
regulating the amount of body fat, insulin, leptin
decreased Leptin
happens with weight loss
a decrease in leptin triggers the hypothalamus to have increased energy intake and decreased energy expenditure
puts adipocyts at set point size
increased leptin
happens with weight gain
it signals to hypothalamus to have decreased energy intake and increased energy expenditurep
puts adipocytes at set point size
Adaptive thermogenesis
a change in expenditure based on intake, ex if you eat more you are more inclined to fidget or go for a walk
futile cycling
the body makes and breakes things down to use up any excess energy
brown adipose tissue
a decoupled ETC, energy becomes heat, so you can lose excess energy as heat
is in infants to help keep them warm
Weight loss goals
aim for 5-15% loss of body weight to reduce risk of disease
at a rate of 0.5-2lb a week
Paleo diet
intended to mimic foods consumed by paleolithic ancestors
eat: grass fed meat, fish, eggs, nuts, seeds, fruits, veggies, oils
do not eat: grains, legumes, dairy, potatoes, processed foods, refined oils, sugar, salt
very low calorie diets
eat 800 calories a day for rapid weight loss
phentermine
is an appetite suppresent
orlistat
is approved by FDA
interrupts the ingestion of fat
could lead to problems with fat solube vitamins
Alli
is an over the counter orlistat
ephedra
is a stimulant that causes weight loss, but also has other effects
gastric bypass
restricts the size of the stomach and bypasses part of the small intestine
gastric banding
put an adjustable band around the stomach, which can adjust the size of the opening into the stomach
gastric sleeve
removal of part of the stomach
What percent calories come from fat in the typical american diet?
34
Examples of foods high in fat
almonds, seeds, cheese, oils, beef, croissant, muffins, cakes
sterol
a type of lipid with a structure composed of multiple chemical rings
sources of saturated fatty acids
red meat, butter, cheese, whole milk, coconut oil, palm oil
sources of monosaturated fatty acids
canola, olice and peanut oil, nuts, avocados
sources of omega 6 fatty acids
corn oil saddlower oil, soybean oil and nuts
are polyunsaturated fatty acids
sources of omega 3 fatty acids
falxseed, canola oil, nuts, fish oils,
are polyunsaturated fatty acids
examples of omega 3 FA
alpha linolenic acid, eicosapentaenoic acid, docosahexenoic acid
examples of omega 6 FA
lenoleic acid
transfatty acids
hydrogens on oppostie sidsm they can pack tightly and have a higher melting point
trans fats raise blood cholesterol levels and increase the risk of heart disease
usually come from hydrogenation
phosphoglycerides
major class of phospholipids
glycerol backbone with 2 FA attached and one phosphate group
can mix with water and fat–emulsifier
lecithin
phosphoglyceride with a glycerol backbone, 2 FA, a phosphate group and a molecule of choline. is in all cell membranes and used to synthesize Ach
is used in foods as an emulsifier
Uses of cholesterol
synthesize vitamin D, cholic acid (bile) and steroid hormones
Where does most lipid digestion occur?
In the SI due to the action of lipid digesting enzymes called lipases
some occurs in the stomach due to gastric lipase
Digestion of lipids
- in SI, bile from gall bladder helps break fat into small globules
- Triglycerides in these globules are broken down by lipases into fatty acids and monoglycerides
- These mix with bile to form micelles
- Micelles are absorbed into mucosal cells
- Long chain fatty acids, cholesterol etx are then processed before entering blood stream
Are lipids soluble in water?
short and mediumchain fatty acids are
long chain, cholesterol and fat soluble vitamins are not
lipoproteins
particle containinf a core of triglycerids and cholesterol surrounded by a shelpp of protein, phospholipids and cholesterol tat transport lipids in the blood and lymph
Chylomicrons
lipoprotein that transports lipid from mucosal cells of the small intestine and delivers triglyceride to other body cells
lipoprotein lipase
breaks down triglycerides into fatty acids and glycerol.
examples of essentail fatty acids
omega 3 (linoleic) and omega 6 (alpha linolenic
essential fatty acid deficiency
characterized by dry scaly skin and poor frowth, when diet doesn’t supply sufficient amonts of essetial fatty acids
eicosanoids
regulatory molecules including prostaglandins and releated compounds that can be synthesized from omega 3 and 6 FA
-help regulate blood clotting, blood pressure, immune function etc.
the effect is determined by what type of fatty acid it is made from
ideal ratio of omega 6 to omega 3
5:1 to 10:1
Beta oxidation
the first step in the production of ATP from fatty acids. This breaks down the carbon chain of fatty acids into 2 carbon units that form acetyl coA and releases high energy electrons that are passed to the ETC
How do triglyceride provide energy?
- beta oxidation to acetyl coa
- glycerol from triglyceride can be used to make ATP or glucose cia gluconeogensis
feasting
excess energy consumed as carbs or protein first go to the liver to be synthesized to fatty acids .
Fatty acids are assembled into triglycerides, which are transpoorted to adipose tissue via VLDLs
lipoprotein lipase breaks down the triglycerides from chylomicrons ad VLDLs so fatty acids can enter cells, where they are reassembled into triglcycerides for stoarge
Fasting
hormone sensitive lipase begins breakinf down stored triglycerides. Fatty acids and glycerol are released directly into the blood where hey can be taken up by cells throughout the body to produce ATP
hormone sensitive lipase
an enzyme present in adipocytes that responds to chemical signals by breaking down triglycerides into fatty acids and glycerol and releasing theminto the bloodstream
atherosclerosis
a type of cardiovascular disease that involves the buildup of fatty material in the artery walls
oxidized LDL cholesterol
a substance formed when the cholesterol in LDL particles is oxidized by reactive o2 molecules. it is key in the development of atherosclerosis because it contributes to the inflammatory response
scavenger receptor
a protein on the surface of macrophages that binds to oxidized LDL cholesterol and allows it to be taken up by the cell
why do saturated fats increase risk for heart disease?
they increase LDL cholesterol in the blood which increases the risk of atherosclerosis
why do B vitamins reduce heart risk?
they keep blood levels of homocystein low.
dietary fat and breast cancer
higher fat diet=faster tumor growth in rates
What are the types of lipids?
triglycerids, fatty acids, phosphoglycerides, sterols
how much alcohol can the body digest in an hour?
0.5 oz
protein digestion
begins in the stomach with HCl denaturing proteins
the acit also activates pepsin, ehich breaks some peptide bonds
most protein digestion occurs in the small intestin where polypeptides are broken into amino acids by trypsin and chymotrypsin
single amonio acids are then absorbed into mucosal cells of the smll intestingamino acid absorption
-one of several active transport systems
some AA compete for the same transport system
protein energy malnutrition
a condition characterized by wasting and an increased susceptibility to infection that results from long term consumption of insufficient amounts of energy and protein to meet needs
Calorie content of egg yolk v white
white-17
yolk-55
protein content of egg yolk v white
white-3.6
yolk-2.7
cholesterol content of egg yolk v white
white-0
yolk-184
choline content of egg yolk v white
white 0.4
yolk 116
vit A content of egg yolk v white
white 0
yolk 245
sodim content of egg yolk v white
WHITE-55
yolk 8
What food are saturated fats found i?
animals: beef, lamb, lard, cream, butter, cheese,
coconut oil, palm oil
What is the effect of saturated fats on the heart?
raise bad cholesterol, high in cholesterol, increase risk of heart disease
Daily limit of saturated fat
less than 7% of daily calories
less than 140- if eating 2000
characteristics of saturated fat
no double bonds
solid at room temp
foods with trans fats
baked goods, fried foods, snack foods, stick margerine
foods with monounsaturated fats
vegetable oils, avocados, olives, nuts and seeds
foods with omega 6 fatty acids
vegetable oils, soybean, corn and safflower, nuts walnuts sunflower seeds
foods with omega 3 fatty acids
fatty fish, salmon tuna trout
effect of transfats on the heart
raise LDL, lower HDL, increase risk of heart disease
effect of monounsaturated fats on the heart
reduce bad cholesterol, lowr risk of heart disease
effect on polyunsaturate fats on the heart
reduce LDL, lower risk of heart disease
characteristics of trans fats
solid at room temp, contained in partially hydrogenated oils
chracteristics of monounsaturated fats
have one double bond, liquid at room temp. solid when chilled
characteristics of polyunsaturated fats
multiple double bonds, liquid always
daily limit of trans fats
less than 1% of daily fats.. 20 cal/2000 cal
daily limit of monounsaturated and polyunsaturated fats
25-35%
cholesterol free label
less than 2mg of cholesterol and 2g sat. fat
low cholesterol
less than 20mg cholesterol and 2g sat .fat
reduced cholesterol
25% less cholesterol than the regular product
