Chapter 5 Flashcards
Lipids and carbohydrates are compose of?
carbon, hydrogen and oxygen
why can lipids supply more energy per gram than carbohydrates can?
lipids have many more carbons and hydrogen’s in proportion to their oxygen’s.
every triglyceride contains?
on molecule of glycerol and three fatty acids (basically, chains of carbon atoms)
most common fatty acids in foods?
18-carbon long (chain)
Fatty acids may be any where from?
4 to 24 carbons long (chain)
Fatty acids may be saturated or?
unsaturated
of special importance in nutrition are the?
polyunsaturated fatty acids known as omega-3 fatty acids and omega-6 fatty acids.
the 18-carbon polysaturated fatty acids are?
linolenic acid (omega-3) and linoleic acid (omega-6)
linolenic acid (omega-3) and linoleic acid (omega-6) are both essential fatty acids that the body?
cannot make for itself. You must get this through food or supplements
saturated fatty acids:
a. are always 18 carbons long
b. have at least one double bond
c. are fully loaded with hydrogens
d. are always liquid at room temperature.
are fully loaded with hydrogens
A triglyceride consists of?
three fatty acids attached to a glycerol
The difference between cis-and trans-fatty acids is?
the configuration around the double bond
Which of the following is not true? Lecithin is:
a. an emulsifier
b. a phospholipid
c. an essential nutrient
d. a constituent of cell membranes
not an essential nutrient
Chylomicrons are produced in the?
small intestine
Transport vehicles for lipids are called?
lipoproteins
Which of the following is not true? Fats: a. contain glucose b. provide energy c.protect against organ shock carry vitamins A,D, E, and K
contain glucose is not true
The essential fatty acids include
linoleic acid and linolenic acid
The lipoprotein most associated with a high risk of heart disease is?
LDL
A person consuming 2200 kcalories a day who wants to meet health recommendations should limit daily fat intake to?
50 to 85 grams
Ch. 6 Proteins form integral parts of most body tissues and provide strength and shape to skin, tendons, membranes, muscles, organs, and bones
Structural materials
Ch. 6 proteins facilitate chemical reactions
Enzymes
Ch. 6 proteins regulate body processes
Hormones (not all hormones are proteins)
Ch. 6 proteins help to maintain the volume and composition of body fluids
fluid balance
Ch. 6 proteins help to maintain the acid-base balance of body fluids by acting as buffers
Acid-base balance
Ch. 6 proteins transport substances, such as lipids, vitamins, minerals, and oxygen, around the body
transportation
Ch.6 proteins inactivate foreign invaders, thus protecting the body against disease
antibodies
Ch.6 proteins provide some fuel, and glucose if needed, for the body’s energy needs
energy and glucose
Ch.6 the protein fibrin creates blood clots; the protein collagen forms scars; the protein opsin participates in vision
other proteins
Define lipids?
A family of compounds that includes triglycerides, phosophlipids, and sterols. Lipids are characterized by their insolubility in water.
Fatty acids have the same basic structure
a chain of carbon and hydrogen atoms with an acid group (COOH) at one end and a methyl group (CH3) at the other end.
a short chain (fewer than 6 carbons) fatty acids also occur primarily in?
dairy products`
Saturated fatty acid found in natural fats.
butyric (butterfat) caproic (butterfat) caprylic (coconut oil) capric (palm oil) laurie (coconut oil, palm oil) myristic (coconut oil, palm oil) palmitic (palm oil) stearic (most animal fats) arachidic (peanut oil) behenic (seeds) lignoceric (peanut oil)
Unsaturated Fatty Acids
palmitoleic (seafood, beef) oleic (olive oil, canola oil) Linoleic (sunflower oil, safflower oil) Linolenic (soybean oil, canola oil Arachidonic (eggs, most animal fats) Eicosapentaenoic (seafood) Docosahexaenoic (seafood)
monounsaturated fatty acid oleic acid is abundant in?
olive oil and canola oil
a polyunsaturated fatty acid has?
two or more carbon-to-carbon double bonds
18-carbon fatty acid common in vegetable oils, lacks four hydrogens and has two double bonds:
Linoleic acid (polyunsaturated fatty acid)
18-carbon fatty acids (chains)
stearic acid (most animal fats) oleic acid (olive and canola oils) linoleic acid (sunflower, safflower, corn, and soybean oils) linolenic acid (soybean and canola oils, flaxseed, walnuts)
linoLENIC acid
an essential fatty acid with 18 carbons and three double bonds.
omega
the last letter of the greek alphabet used by chemists to refer to the position of the closet double bond to the mehyl (CH3) end of fatty aids
omgea-3 fatty acid
a polyunsaturated fatty acid in which the closest double bond to the methyl (CH3) end of the carbon chain is three carbons away.
omga-6 fatty acid
a polyunsaturated fatty acid in which the closet double bond to the methyl (CH3) end of the carbon chain is six carbons away.
triglycerides
the chief form of fat in the diet and the major storage from of fat in the body; composed of a molecule of glycerol with three fatty acids attached; also called triacylglycerols
glycerol
an alcohol composed of a three-carbon chain, which can serve as the back bone for a triglyceride
condensation
a chemical reaction in which water is released as two molecules combine to form one larger product.
fats
lipids that are solid at room temperature (77 f or 25 c)
oils
lipids that are liquid at room temperature (77 f or 25 c)
oxidation
the process of a substance combining with oxygen, oxidation reactions involve the loss of electrons
antioxidants
as a food additive, preservatives that delay or prevent rancidity of fats in foods and other damage to food caused by oxygen.
hydrogenation
a chemical process by which hydrogens are added to monounsaturated or polyunsaturated fatty acids to reduce the number of double bonds, making the fats more saturated and more resistant to oxidation. Hydrogenation produces trans-fatty acids
cis
hydrogen atoms are located on the same side as a double bond
trans
a fat is partially hydrogenated, and some of the double bonds that remain after processing change their configuration from cis to trans
trans-fatty acids
fatty acids with hydrogens on opposite sides of the double bond
conjugated linoleic acids
several fatty acids that have the same chemical formula as linoleic acid but with different configuration (double bonds occur on adjacent carbons)
phospholipid
a compound similar to a triglyceride but having a phosphate group and choline in place of one of the fatty acids
lecithin
one of the phospholipids. both nature and the food industry use lecithin as an emulsifier to combine water-soluble and fat-soluble ingredients that do not ordinarily mix such as water and oil.
choline
a nitrogen-containing compund found in foods and made in the body from the amino acid methionie. Choline is part of the phospholipid lecithin and the neurotransmitter acetylcholine.
hydrophobic
a term referring to water fearing, or non-water-soluble, substances; also known as lipophilic (fat loving)
hydro
phobia
lipo
phile
water
fear
lipid
love
hydrophilic
a term referring to water loving, or water-soluble, substances
emulsifiers
substances with both water-soluble and fat soluble portions that promote the mixing of oils and fats in watery solutions.
sterols
compounds containing a four-ring carbon structure with any of a variety of side chains attached
cholesterol
one of the sterols containing a four-ring carbon structure with a carbon side chain
endogenous
from within the body
endo=within
gen=arising
exogenous
from outside the body
exo=outside
plaque
an accumulation of fatty deposits, smooth muscle cells, and fibrous connective tissue that develops in the artery walls in atherosclerosis. Plaque associated with atherosclerosis is known as atheromatous
atherosclerosis
a type of artery disease characterized by plaques on the inner walls of the arteries
lipases
enzymes that hydrolyze lipids. Lingual lipase refers to the fat-digesting enzyme secreted from the salivary gland at the base of the tongue.
monoglycerides
molecules of glycerol with one fatty acid attached. A molecule of glycerol with two fatty acids attached is a diglyceride.
small intestines Fat digestion in the GI tract
cholecystokinn (cck) signals the gallbladder to release bile (via the common bile duct)
Fat———Bile————–> Emulsified fat
pancreatic lipase flows in from the pancreas (via the pancreatic duct):
Emulsified fat——pancreatic lipase——> monoglycerides glycerol, fatty acids
Lg. intestine Fat digestion in the GI tract
some fat and cholesterol, trapped in fiber, exit in feces
stomach Fat digestion in the GI tract
churning actions mixes fa with water and acid. A gastric lipase accesses and hydrolyzes fat
micellers
tiny spherical complexes of emulsified fat that arise during digestion, most contain bile salts and the products of lipid digestion, including fatty acids, monoglycerides, and cholesterol
lipoproteins
clusters of lipids associated with proteins that serve as transport vehicles for lipids in the lymph and blood
chylomicrons
the class of lipoproteins that transport lipids from the intestinal cells to the rest of the body
large lipids
such as monoglycerieds and long-chain fatty acids combine with bile, forming micelles that are sufficiently water soluble to penetrate the watery solution that bathes the absorptive cells. There the lipid contents of the micelles diffuse into the cells.
Glycerol and small lipids
such as short-and medium-chain fatty acids can move directly into the bloodstream
VLDL (very-low-density lipoprotein)
the type of lipoprotein made primarily by liver cells to ransport lipids to various tissues in the body, coposed primarily of triglycerides
LDL(low-density lipoprotein)
the type of lipoprotein derived from very-low density lipoproteins as triglycerides are removed and broken down, composed primarily of cholesterol.
HDL (high-density lipoprotein)
the type of lipoprotein that transports cholesterol back to the liver from the cells composed primarily of protein
adipose tissue
the body’s fat tissues, consists of masses of triglyceried-storing cells
adipokines
proteins synthesized and secreted by adipose cells
essential fatty acids
fatty acids needed by the body but not made by it in amounts sufficient to meet physiological needs
arachidonic acid
an omega-6 polyunsaturated fatty acid with 20 carbons and four double bonds, present in small amounts in meat and other animal products and synthesized in the body from linoleic acid
conditionally essential nutrient
a mutrient that is normally nonessential, but must be supplied by the diet in special circumstances when the need for it exceeds the body’s ability to produce it.
eicosapentaenoic acid
an omega-3 polyunsaturated fatty acid with 20 carbons and five double bonds; present in fatty fish and synthesized in limited amounts in the body from linolenic acid
docosahexaenoic acid
an omega-3 polyunsaturated fatty acid with 22 carbons and six double bonds, present in fatty fish and synthesized in lmited amounts in the body form linolenic acid.
eicosanoids
derivatives of 20-carbon fatty acids, biologically active compounds that help to regulate blood pressure, blood clotting, and other body functions. They include prostaglandins and leukotrienes
lipoprotein lipase (LPL)
an emzyme that hydrolyzes triglycerides passing by in the bloodstream and directs their parts into the cells, where they can be metabolized for energy or reassembled for storage.
hormone-sensitive lipase
an enzyme inside adipose cells that responds to the body’s need for fuel by hydrolyzing triglycerides so that their parts escape into the general circulation and thus become available to other cells for fuel. The signals to which this enzyme responds include epinephrine and glucagon, which oppose insulin
blood lipid profile
results of blood tests that reveal a person’s total cholesterol, triglycerides, and various lipoproteins
cardiovascular disease (CVD) cardio=heart vascular=blood vessels
diseases of the heart and blood vessels throughout the body. Atherosclerosis is the main cause of CVD. When the arteries that carry blood to the heart muscle become blocked, the heart suffers damage known as coronary heart disease (CHD)
Major sources of saturated fats
whole milk, cream, butter, cheese, ice cream
fatty cuts of beef and pork
coconut, palm, and palm kernel oils
major sources of trans fat
cakes, cookies, doughnuts, pastry, crackers
margarine
deep-friend foods
snack chips
major sources of cholesterol
eggs
milk and milk products
Meat, poultry, shellfish
1g fat
9Kcal
1g carbs
4 Kcal
DRI and dietary guidelines for fat
20 to 35% of energy intake
major sources of unsaturated fats
monounsaturated fats and polyunsaturated fats
monounsaturated fats
olive oil, canola oil, peanut oil, safflower oil, avacodos
Polyunsturated fats
vegetable oils
nuts and seeds
major sources of moega-3 fats
vegetable oils (canola, soybean, flaxseed)
walnuts, flaxseeds
fatty fish, salmon, sardines
omega-6 for men
19-50 yrs 12g/day
fat replacers
ingredients that replace or some or all of the functions of fat and may or may not provide energy
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
a synthetic fat made from sucrose and fatty acids that provides 0 kcalories per gram, also known as sucrose polyester
