chapter 6

saturated fatty acid

a fatty acid that has each carbon atom chain is filled with hydrogen atoms

CVD

a group of disease that affect the heart and blood vessels(like stroke, coronary artery disease)

cholesterol

a lipid found in animal foods, precursor for steroid hormones, bile and vitamin D so it must be there to create these(rich sources are egg, dairy products and liver and meat)

triglycerides

a lipid that has three fatty acids attached to three carbon component known as glycerol

glycerol

a three carbon alcohol that forms the backbone of fatty acids (95 percent of lipids in the body)

embolus

a thrombus or part of a plague that breaks free and travels through the bloodstream

short and medium chain fatty acids

diffuse into the absorptive cells of the villi -enter the capillary network long chain fatty acids require extra steps

modifiable risk factors for atherosclerosis

elevated blood cholesterol -excess body fat, physical inactivity(activity increase your HDL), hypertension, tobacco use

lipoprotein profile

evaluates total cholesterol, HDL, cholesterol, LDL, cholesterol and triglyceride levels

non modifiable risk factors for atherosclerosis

family -age race/ethnic background

essential fatty acids

fatty acids that are supplied by the diet(linoleic and alpha linolenic acid) AA, EPA , and DHA are precursors to eicosanoids( group of long chain fatty acids that act like hormones) prostaglandins are essential fatty acids that help with uterine contractions

lipase

first involved in lipid digestion

thrombus

fixed bunch of clots that remain in place and disrupt blood flow

gallstone

hard particles that accumulate in the gallbladder or become lodged in one of the ducts carrying bile from gallbladder to small intestine

VLDL

has a lot of triglycerides and some phospholipid ) (is very bad and is made in the liver)(once they have been stripped of most of their fat by LPL they become low density or LDL)

polyunsaturated fatty acid

has two or more double bonds within carbon chain(we have alpha line fatty acid and lineic acid(both of those are omega fatty acids)

fatty acid

hydrocarbon chain found in lipids where one end of the chain forms a carboxylic acid and one end forms a methyl group(also has a hydrocarbon chain) have short,medium and long chain fatty acids(idenftified by the number of carbons

emulsification

hydrophobic parts are on inside of the oil because it is attracted to those parts and hydrophilic parts are on the outside(wrapping up oil in water casing)

fat malabsorbtion

impaired fat absorption, symptoms include diarrhea, steatorrhea, and rapid weight loss

sterols

lipids that have a more chemically complex structure than a triglyceride and fatty acid(like cholesterol)

atherosceloris

long term illness in which plague builds upside arterial walls

unsaturated fatty acid

missing hydrogen atoms and has one or more double bonds within carbon chain

trans fat vs cis fat

most naturally occurring unsaturated fatty acids are cis fatty acids and trans fats are unsaturated fatty acids that have a trans double bond(for cis the hydrogens are on the same side and for trans fat the hydrogens are on different sides)

most triglycerides in food contain a mixture of unsaturated and saturated fatty acids(one type of fatty acid will predominate)

most triglycerides in food contain a mixture of unsaturated and saturated fatty acids(one type of fatty acid will predominate)

monounsaturated fatty acid

one double bond within carbon chain

Lipoproteins and Atherosclerosis

oxidized LDL- LDL that has been damaged by free radicals and contributes to atherosclerosis (damage makes LDL worse) and this oxidized LDL transfers cholesterol into the arterial lining VLDL shuttle lipids to adipose cells(which are cells that store triglycerides) -as blood concentration of triglycerides increases(HDL levels decrease leading to maybe CVD)

trans fats in food

partial hydrogenation is a process that adds hydrogen vegetables oil and this forms trans fats(products can be stored for a longer period) enrichment and fortification don't always work(adding hydrogen produces harmful effects and it can raise your cholesterol leading to CVD)

phospholipids part 2

phospholipids are both hydrophobic and hydrophilic which makes them partially water soluble (hydrophobic attracts fat and repels water) -since it has both hydrophobic and hydrophilic region it can serve as an emulsifie

Enteropathic circulation

process that recycles bile salts(incorporated into new bile)(98 percent of bile is reabsorbed in ileum and is sent to the liver which incorporates this bile into new bile) some plants contain soluble fibers that interfere with cholesterol and bile absorbtion(helps reduce blood cholesterol levels)

dietary changes to prevent CVD

replace saturated with unsaturated fat limit trans fat eat fewer solid fats eat seafood(omega 3 fatty acids) eat foods rich in fiber(prevents the recycling of bile salts) consume less alcohol

arteriosclerosis

results from atherosclerosis and is characterized by loss of arterial flexibility (the vessels have narrowed as a result and are stiff and hard so blood flow is poor as a result)

long chain fatty acids

specifically long chain fatty acids bile ,cholesterol, and fat soluble vitamins pack together in micelles(water soluble lipid cluster) when micelles come close to the villi, they can diffuse into the absorptive cells or the enterocytes of the villi in the small intestine

CCK

stimulates gallbladder to release bile and secrete digestive enzymes such as pancreatic lipase)

secretin

stimulates liver to release bile and also stimulates the release of bicarbonate pancreatic solution

summary of lipid digestion

stomach-minor digestion of fat liver- produces bile salts pancreas- introduces enzymes like pancreatic lipase that helps in digestion in small intestine small intestine- primary site for absorption and digestion of lipids, once absorbed long chain fatty acids are packaged for transport through the lymph and bloodstream anus- less than 5 percent of undigested fat is excreted here

cholecstectomy

surgical removal of the gallbladder(this makes digestion of fat very difficult because we don't have that extra bile from the gallbladder

lipid transportation

this is after absorption where fatty acids, glycerol, monoglycerides, and phospholipid fragments are reassembled into triglycerides and phospholipids within the absorptive cells

gaucher disease

this is caused by the deficiency of the enzyme glucocerebrosidase(lipid accumulation in bone marrow) a lipid storage disease

phospholipids

type of lipids needed to make cell membranes and for proper functioning of nerves and they are chemically similar to triglyceride except one of the fatty acids is replaced by a chemical group that contains phosphorus

omega fatty acids

types of polyunsaturated fats that are based on where the double carbon bonds are alpha linelic is an omega 3 and it branches into DHA and EPA (our first double carbon bond is at the third carbon) linelic acid is omega 6 and it branches into AA(at the sixth carbon)

lipoproteins

water soluble molecules that tranports lipids

choline

water soluble vitamin like compound and a component of lecithin (found in egg yolks, wheat germs and used to form acetylcholine)

pancreatic lipase

leaves two fatty acids from each lipid molecule

LDL

(has a lot of cholesterol and very little triglyceride)(it's job is to get rid of cholesterol into the tissues because it has pretty much of it so elevated LDL is linked to increased risk of CVD)

HDL

(has a lot of protein and very little triglyeride)

transportation chylomicrons

-the lymphatic system transport chylomicrons to the thoracic duct -enter the blood stream through the left subclavian vein -circulate through the body -LPL an enzyme in capillary wall which breaks down the triglycerides

lipids

a class of nutrients that do not dissolve in water, includes triglycerides phospholipids and sterols (dissolve in organic solvents)

bile salts

a component of bile and aid in lipid digestion(emulsification)(combine lipids with water)

major function of lipids

absorb fat soluble vitamins and phytochemical -cushion the body against bumps and blows form and maintain cell membranes form body counters produce steroid hormones provide and store energy(I'm surprised by this of how many benefits there are for fats)

dietary guidelines for fats

adults should emphasize foods that are rich in PUFAs and MUFAs(fishes, nuts, vegetable oil)

Homocysteine

an amino acid that plays a role in the development of atherosceloris (toxic byproduct of protein metabolism)(damage the blood vessels causing cascade of events for atherosceloris)

C reactive protein

an inflammatory marker for CVD and is produced in response to inflammation and CVD involves chronic inflammation(lets you know if you have CVD or not)

atherosclerosis in carotid arteries

atherosceloris in these arteries can reduce blood flow and clots can form that travel to the brain causing stroke

Lipid absorbtion steps

bile salts surround the fatty acids and monoglycerides to form a water soluble particle called micelle. micelles transport the lipids to the edge of the absorptive cell. these cells remove the monoglycerides and fatty acids from the micelles. absorptive cells remove the end products of lipid digestion from micelles monoglycerides and long chain fatty acids combine to become triglycerides the absorptive cell packages the triglycerides with some cholesterol and coats the particle with protein and phospholipids to form a chylomicron the chylomicron enters the lacteal and eventually enters the bloodstream (majority of this occurs in small intestine)

plant sterols

chemicals found in plants that are structurally similar to cholesterol(found in grains, fruits, vegetables, nuts, seeds and legumes)

lipid transportation part 2

cholesterol and reassembled triglycerides are coated with a thin layer of protein phospholipids and cholesterol to form chylomicrons(chylomicron is a type of lipoprotein formed in enterocytes)

Lipid Digesgion Step part 1

in response to presence of fatty chyme in the duodenum, the gallbladder, release bile into the chyme. Bile contains bile salts which emulsify the lipids pancreatic lipase digest these molecules more easily specifically pancreatic lipase helps by digesting or getting rid of two fatty acids from each triglyceride molecule which converts most fat into monoglycerides and free fatty acids glycerol ,fatty acids and monoglycerides are the major products of lipid digestion

How atherosclerosis develops

injured arterial lining becomes inflamed -WBC or white blood cells become laden with oxidized LDL particles -arterial plague, a fatty building in arteries forms interfering with circulation (makes clots more likely to form straight line of blood flow is meeting a lot of interference with the condition of atheroscleorosis(blood flow becomes turbulent and it promotes coagulation)