Chapter 5: Fats Flashcards
why has fat intake increased over the years?
caloric intake had increased
what are lipids?
organic molecules that don’t dissolve in water
example) fatty acids, triglycerides, phospholipids, and sterols
what are triglycerides?
- major form of lipids in the body
- 3 fatty acids attached to a 3 carbon molecule called “glycerol”
what does hydrophobic mean?
doesn’t dissolve in water
what are phospholipids?
- a lipid that contains a phosphorus atom
- allows water and fat to mix due to it’s hydrophilic and hydrophobic properties
what are sterols?
- a lipid that is composed of multiple chemical rings
- found in plants, lean/fatty parts of animal, and every cell in the human body
what is a fatty acid?
a chain of carbons linked to hydrogen with an acid group at the end of the chain
what role do fatty acids play in triglyceride function?
the type of fatty acid will determine triglyceride function
what is the determining factor on whether a fatty acid is saturated or unsaturated?
fatty acid is saturated or unsaturated depending on whether there’s carbon to carbon bonds
what is a saturated fat?
- no double bonds
- saturated with hydrogen bonds
- solid at room temperature (butter)
- common in animal products
- associated with cardiovascular disease
what is an unsaturated fat?
- 1 or more double bonds
- no room for hydrogen atoms
- liquid at room temperature (canola oil)
why is saturated fat associated with cardiovascular disease?
has high levels of low density lipoproteins (LDL), called “bad cholesterol”
what type of chain do saturated fats have?
medium chain
- 6-10 carbons long
- quickly absorbed into blood stream
- less likely to be stored as fat
- saturated plant oils less susceptible to spoilage
how does spoilage happen?
occurs when unsaturated bonds in fatty acids are damaged by oxygen
what are 2 types of unsaturated fats?
- monounsaturated fat
2. essential fatty acids
what are monounsaturated fats?
- 1 double bond
- found in meat, olive oil, avocados, and nuts
- an increase in monounsaturated fats, decreases low density lipoprotein (LDL) cholesterol
what are 2 types of essential fatty acids?
- alpha-linoleic acid (omega-3)
2. linoleic acid (omega-6)
what is the function of essential fatty acids?
provide health benefits beyond normal fat benefits in the body
- important for phospholipid formations
- necessary for brain development in children
what are eicosanoids?
- made from omega-3 and omega-6
- regulates blood clotting, blood pressure, and immune function
- decreases risk of heart disease
what are symptoms of essential fatty acid deficiency?
- dry skin
- liver abnormalities
- poor healing
- impaired vision
- growth failure
what is hydrogenation?
process where hydrogen atoms are added to carbon double bonds of unsaturated fatty acids to increase shelf life
what is the relation between trans fatty acids and heat disease?
increases the risk of heart disease because of it’s high levels of low density lipoproteins (LDL) and low levels of high density lipoproteins (HDL)
what is an emulsifier? give an example.
substance that allows fat and water to mix
example) lecithin
what is cholesterol?
- produced by liver and consumed in the diet
- needed to build cell membranes and make other hormones
what is the relationship between cholesterol and heart disease?
- animal sources increase the risk of heart diseased because of the high consumption of saturated and trans fat
- plant sources can held reduce cholesterol levels
what is bile?
emulsifier that breaks down lipid droplets into small globules
how does bile emulsify fat?
turns the hydrophilic end of the fat towards water and the hydrophobic ends towards other lipids
what is the function of pancreatic enzymes in fat digestion?
digests triglycerides into globules
what is a micelle?
formed in small intestines when products are surrounded by bile, facilitates absorption
what are lipoproteins?
particles that transport lipids in the blood
how are lipoproteins formed?
when substances that are not soluble in water are present, protein, phospholipids, and cholesterol form a lipoprotein
what are chylomicrons?
- lipoprotein for triglyceride packaging
- too large to enter capillaries so they must go through the lymphatic system before entering blood stream
what is lipase?
- a lipoprotein that promotes uptake of triglycerides in chylomicrons
- breaks down triglycerides into fatty acids and glycerol
what are very low density lipoproteins?
consists of triglycerides that circulate in the blood
what are low density lipopproteins?
- transports cholesterol to cells
- made in body
- increases risk of heart disease
how is cholesterol eliminated from our system?
brought to the liver for elimination
what are high density lipoproteins?
- picks up cholesterol from cells and transports it to the liver for elimination
- made in body
- decreased risk of heart disease
what is the use of cholesterol?
used to make steroid hormones and important components of cell membranes and myelin coating
what is adipose tissue?
- where most lipids are stored
- contains large triglyceride droplets that enlarge when weight is gained
what are adipocites?
fat cells that are formed when triglyceride droplets reach it’s maximum size and divide
how do we store triglycerides?
chylomicrons transport fat from intestines to adipose tissue for storage
how do we retrieve energy from fat stores?
- when we consume inadequate amount of calories, enzymes receive a signal to break down triglycerides
- fatty acids and glycerol are released into the blood and circulate in the body
- cells take up products to produce ATP
what is cardiovascular disease?
any disease that affects the heart and/or blood vessels
what is atherosclerosis?
- when cholesterol enters artery walls reducing elasticity and limiting blood flow
- develops when diets are high in trans fat, saturated fat, and cholesterol
what is artherosclerosis plaque?
- cholesterol-rich material is deposited in arteries of individuals with atherosclerosis
- consists of cholesterol, smooth muscle cells, fibrous tissue, and calcium
what are the primary risk factors for heart disease?
- high LDL cholesterol
- smoking
- high blood pressure
- physical inactivity
- obesity
- diabetes
what are antioxidants?
substances that neutralize reactive oxygen molecules and prevent cell damage
what is the adequate intake amount for linoleic acids in men and women?
- 12g for women
- 17g for men
what is the adequate intake amount for alphalinoleic acids in men and women?
- 1.1g for women
- 1.6g for men
what is the AMDR reccomendation of fat for children?
- 30-40% (1-3 years)
- 25-35% (3-18 years)
