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Nutrition 250
Exam #2 (5-6)
109
Medical
Undergraduate 2
02/14/2012

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Cards

Term
Carbohydrate Family
Definition
Sugar, starch, and fiber; mostly composed of carbon, hydrogen, and oxygen; main source is plants
Term
Photosynthesis
Definition
Plants produce glucose by using carbon and oxygen from carbon dioxide in the air, hydrogen from water, and energy from the sun; plants either store glucose or transform it into starch, fiber, fat or protein
Term
General Form of Carbs
Definition
CH2O
Term
Monosaccharide
Definition
Class of single sugars that are not broken down further during digestion; CH2O6
Term
Hexose
Definition
6-carbon sugar, including glucose, fructose, and galactose
Term
Glucose (Mono/Hex)
Definition
Most abundant monosaccharide; also called dextrose; “blood sugar”
Term
Fructose (Mono/Hex)
Definition
Monosaccharide found in fruits, veggies, and honey; also called levulose
Term
Galactose (Mono/Hex)
Definition
Monosaccharide found most abundantly as a part of lactose (milk sugar)
Term
Sugar Alcohols
Definition
Derivatives of monosaccharides, include sorbitol, mannitol, and xylitol; used primarily as sweeteners in sugarless gum, and dietetic food; don't promote dental caries; contribute 1.5-3 kcal/g
Term
Pentose
Definition
5-carbon sugar, including ribose, and deoxyribose which are only needed in small quantities but are very important b/c they make up RNA and DNA
Term
Disaccharide
Definition
Class of sugars formed by the chemical bonding of 2 monosaccharides; CH2O12
Term
Condensation Reaction
Definition
Chemical reaction in which 2 molecules bond to form a larger molecule by releasing water; such as glucose and fructose becoming sucrose
Term
alpha Bond
Definition
C-O-C bond found in maltose (2 glucose), sucrose (glucose+fructose), starch (multiple glucose (branched/chain)), and glycogen(highly branched chain of glucose)
Term
beta Bond
Definition
C-O-C bond found in lactose (galactose+glucose)
Term
Maltose
Definition
Contains 2 glucose molecules joined by an alpha bond
Term
Sucrose
Definition
Common table sugar, is composed of glucose and fructose linked by an alpha bond; found naturally in plants
Term
Lactose
Definition
Primary sugar in milk and milk products, consists of glucose joined to galactose by a beta bond
Term
Oligiosaccharides (3-10)
Definition
Complex carbs that contain 3-10 sugar units; made using glycosidic bonds; can't be broken down by digestive enzymes; include raffinose and stacchyose
Term
Raffinose (gal/glu/fru) & Stachyose (gal/gal/glu/fru)
Definition
Oligosaccharides found in onions, cabbage, broccoli, whole wheat, and legumes; pass undigested into the large intestines where bacteria metabolize them producing gas
Term
Polysaccharide
Definition
Class of complex carbohydrates containing many glucose units, from 10 to 1000 or more; glycogen, starch, fiber
Term
Starch (digestible)
Definition
Major digestible polysaccharide in our diets, is the storage from of glucose in plants; there are 2 types of plant starch: amylose & amylopectin; a-bond
Term
Amylose (starch)
Definition
Straight chain molecule; storage form in plants; energy source for plants and animals; found in potatoes, beans, breads, pasta, and rice; typically in a 1:4 ratio with amylopectin
Term
Amylopectin (starch)
Definition
Highly branched molecule; storage form in plants; enzymes only act at the end of glucose chains, therefore Amylopectin gets digested faster
Term
Glycogen (digestible)
Definition
The storage form of carbohydrate in humans and animals, also contains many glucose units linked together with alpha bonds; similar structure to amylopectin but even more highly branched; broken down quickly; a-bond; 400 kcal is stored in the liver, with 1400 kcal stored in the muscles
Term
Total Fiber (indigestible)
Definition
Dietary fiber found naturally in foods + functional fiber that may be added to foods
Term
Functional Fiber (indigestible)
Definition
Fiber that provides health benefits
Term
Fiber (indigestible)
Definition
Non-starch plant polysaccharide; glucose molecule linked by B-bonds; cannot be broken down by human digestion; composed primarily of the non-starch polysaccharides cellulose, hemicellulose, pectin, gum, and mucilages; lignins are the only non-carbohydrate component of dietary fiber
Term
Cellulose (apple skin), Hemicellulose (inner apple), and Lignin (bran)
Definition
Form structural part of the plant cell wall in veggies and whole grains; insoluble
Term
Bran
Definition
Outer covering layer of all seeds
Term
Insoluble Fiber
Definition
Fibers that are not easily dissolved in water or metabolized by bacteria in the large intestine; including cellulose, some hemicelluloses, and lignins; decrease intestinal transit time, thus reducing the risk of constipation, diverticular disease, and colon cancer
Term
Soluble Fiber
Definition
Fibers that dissolve in water and can be metabolized (fermented) by bacteria in the large intestine; includes pectins, gums, mucilages; also called viscous fibers; have been shown to lower the levels of blood cholesterol and blood glucose, thereby reducing risk of CVD; yields 1.5-2.5 kcal/g
Term
Nutritive Sweeteners
Definition
Can be metabolized and yield energy; monosaccharides and disaccharides; such as sucrose, high-fructose corn syrup, and sugar alcohol
Term
Diverticular Disease
Definition
Small pouches lining colon becoming inflamed and painful; most likely caused by low-fiber diet
Term
Alternative Sweeteners
Definition
Provide no food energy; includes saccharin, cyclamate (banned in '70), aspartame, neotame, sucralose, acesuflame-K, and tagatose, 7 sweet n' low, 80 equal, 14 cans of diet soda; does not promote dental caries
Term
Acceptable Daily Intake (ADI)
Definition
Estimate of the amount of sweetener that an individual can safely consume daily over a lifetime. ADIs are given as mg per kg of body weight per day; set at a level 100 times less than that of no harmful effects being noted
Term
Carb Recommendations
Definition
RDA recommends 130 g / day of digestible carbs; 45%-65% of diet; US = 1/2; World = 70%-80%
Term
Sugar Recommendations
Definition
Dietary Guidelines for Americans recommends limiting added sugars to 6% of total energy intake; Institute of Med's Food & Nutrition Board set an upper limit of 25% energy intake for added sugars; increases risk of dental caries; fructose associated with CVD; Type 2 diabetes caused more so by "supersizing" meals; increase LDL, lowers HDL
Term
Nutritious Diet Recommendations
Definition
6 oz of grains, 2.5 cups of veggies, 2 cups of fruit, 3 cups of milk
Term
Red Blood Cells & Central Nervous System Cells
Definition
Derive almost all of their energy from glucose
Term
Amino Acids
Definition
Make up dietary protein and build body tissue, when there is not enough carbohydrate intake to yield glucose, the body is forced to break down amino acids in your muscles and other organs to make glucose
Term
Gluconeogenesis
Definition
Synthesis of new glucose by metabolic pathways in the cell. Amino acids derived from protein usually provide the carbons for this glucose
Term
Ketosis
Definition
When carb intake is below 50 – 100 g / day, the necessary amount to break down fats into carbon dioxide and water; insulin release is decreased, fatty acids from adipose tissue are released into the bloodstream and liver to be used as energy; incomplete breakdown of these fatty acids in the liver results in the formation of acidic compounds called ketone-bodies or keto-acids
Term
Insulin
Definition
Hormone produced by beta cells in the pancreas. Among other processes, insulin increases the movement of glucose from the bloodstream into body cells, increases the synthesis of glycogen in the liver, and decreases the breakdown of fat (lipolysis)
Term
Diverticulosis
Definition
Asymptomatic (without noticeable symptoms) form of diverticula
Term
Diverticulitis
Definition
When diverticula become inflamed and symptomatic
Term
Amylase
Definition
Enzyme in saliva which mixes with starch containing amylose when food is chewed; amylase breaks down the starch into smaller polysaccharide and disaccharide units
Term
Maltase
Definition
Acts on maltose from starchy foods to produce 2 glucose molecules
Term
Sucrase
Definition
Breaks down sucrose to produce glucose and fructose
Term
Lactase
Definition
Digest lactose to produce glucose and galactose
Term
Active Absorption
Definition
How all monosaccharides (glucose, galactose) are absorbed aside from fructose; uses ATP
Term
Facilitated Diffusion
Definition
How fructose is absorbed; doesn't use energy/ATP
Term
1. Mouth (carb digestion)
Definition
Some starch is broken down to polysaccharide and disaccharide units by salivary amylase
Term
2. Stomach (carb digestion)
Definition
Salivary amylase is inactivated by the acidity in the stomach, no further digestion occurs in the stomach
Term
3. Pancreas (carb digestion)
Definition
Pancreatic amylase is secreted into the small intestine to break polysaccharides from starch into disaccharides
Term
4. Small Intestine (carb digestion)
Definition
Enzymes in the wall of the small intestine break down the disaccharides into monosaccharides
Term
5. Liver (carb digestion)
Definition
The absorbed monosaccharides are transported to the liver by the portal vein
Term
6. Large Intestine (carb digestion)
Definition
In the large intestine some soluble fiber is metabolized into acids and gases by bacteria in the large intestine
Term
7. Rectum/Anus (carb digestion)
Definition
Insoluble fiber escapes digestion and is excreted in feces
Term
Fiber Recommendations
Definition
AI: 14 g / 100 kcal consumed
Term
Glycemic Index
Definition
Ranks foods according to their effect on blood glucose levels compared to a standard (glucose or white bread); response/standard; Low = 55 or less, Medium = 56-69, High = 70 or more
Term
Glycemic Load
Definition
Adjusts the GI to amount of carbs usually consumed in a serving; GL = (GI x Carbs (g) in 1 serving) / 100; Low = < 10, Intermediate = 11-19, High = > 20
Term
Very High Fiber Diets
Definition
Above 50-60 g / day; can lead to hard, dry stool, and decreased absorption of certain vitamins and minerals such as iron and zinc
Term
Liver (diabetes)
Definition
Decides how much glucose remains in circulation
Term
Pancreas (diabetes)
Definition
Produces and secretes insulin
Term
Glucagon
Definition
Promotes breakdown of glycogen, when blood glucose levels are low
Term
Hyperglycemia
Definition
High blood glucose; >126 mg / dl; typical of diabetes
Term
Hypoglycemia
Definition
Low blood glucose; <50 mg / dl
Term
Fasting blood glucose level
Definition
70 - 100 mg / dl
Term
Diabetes
Definition
> 126 mg glucose / dl; pre-diabetes = 100-126 mg glucose / dl; results in 200,000 deaths a year; type 1- autoimmune attack; type 2- (90%)acquired insulin resistance; 7.8% of Americans; 1.6 million new cases/year; 23% over 60 years old
Term
Triglycerides
Definition
Most common lipid; 95% of what we eat/what is stored; fat-soluble (doesn't dissolve in water); commonly called butter, lard, oil, or margarine
Term
Triglyceride Structure
Definition
Consist of 3 fatty acids bonded to a glycerol backbone
Term
Esterification
Definition
Process of attaching a fatty acid to a glycerol, yields a water molecule for each fatty acid attachment
Term
De-Esterification
Definition
Release of fatty acids from a glycerol backbone
Term
Fatty Acid Structure
Definition
They are chains of carbons; have two ends: methyl group, carboxyl group; structure can vary in 3 ways: carbon chain length, saturation, and shape
Term
Short Chain Fatty Acid
Definition
< 6 carbons; butter and milk
Term
Medium Chain Fatty Acids
Definition
6-10 carbons; coconut and palm oil
Term
Long Chain Fatty Acids
Definition
>12 carbons; plant oils, pork, lamb fat
Term
Saturated Fatty Acid
Definition
Every carbon has formed a maximum of 4 bonds, each formed with a separate atom; aka "stearic"
Term
Monounsaturated Fatty Acid
Definition
2 carbons form a double bond by each giving up 2 hydrogens; one unsaturated location; aka "oleic"; "cis" form results in kinked carbon chains
Term
Polyunsaturated Fatty Acid
Definition
At least two double bonds; 2+ unsaturated locations; aka "linoleic"
Term
Trans Fatty Acid
Definition
Similar to a monounsaturated fatty acid with one double bond, but the hydrogens attachment zig zags back and forth; "trans" form results in straight carbon chains
Term
Naming Fatty Acids
Definition
18 (# of carbons):3 (number of double bonds) oo (omega = H end)3 (location of first double bond counted from omege (oo) end)
Term
Essential Fatty Acids
Definition
Humans can synthesize most fatty acids; unable to synthesize double bonds before oo9 position; 2 PUFAs are essential: alpha-linolenic (oo3) (3 double bonds) and linoleic acid (oo6)(2 double bonds)
Term
Triglyceride Functions
Definition
Provide energy, compact energy storage, insulate and protect the body, aid fat-soluble vitamin absorption/transport, essential fatty acid functions
Term
Phospholipids
Definition
Water-soluble and fat-soluble; disperse in water; similar to triglycerides except one fatty acid is replaced with a phosphate that often has nitrogen attached; the head is water loving (attracted to water), the tail is water fearing (attracted to fats)
Term
Phospholipid Structure
Definition
Made of a glycerol, 2 fatty acids, and a choline
Term
Emulsifier
Definition
Compound that forms a shell around fat droplets, so that the droplets can be suspended in water and not clump together
Term
Sterols
Definition
Fat soluble properties; don't dissolve in water
Term
Sterols Structure
Definition
Made up of a complex ring structure, and a fatty acid tail; not an energy source; waxy
Term
1. Mouth (lipid digestion)
Definition
Lingual lipase is secreted; little or no fat is digested
Term
2. Stomach (lipid digestion)
Definition
Gastric lipase is secreted, little fat is digested
Term
3. Liver (lipid digestion)
Definition
Bile is produced here, which is stored and released by the gallbladder into the common bile duct, which empties into the small intestine. Bile emulsifies fat
Term
4. Pancreas (lipid digestion)
Definition
Secretes pancreatic lipase, phospholipase, and cholesterol esterase into the common bile duct, which empties into the small intestine; Pancreatic lipase digest triglycerides; Phospholipase digest phospholipids; Cholesterol esterase digest cholesterol
Term
5. Small Intestine (lipid digestion)
Definition
Fat is digested and absorbed in the duodenum and jejunum; bile is reabsorbed in the ileum
Term
6. Large Intestine
Definition
Less than 5% of fat passes through the large intestine and is excreted; also short chain fatty acids produced by bacteria are absorbed
Term
Cholecystokinin (CCK)
Definition
Hormone secreted if fat is present in the small intestine, it stimulates the release of bile from the gallbladder and lipase/colipase from the pancreas; bile emulsifies fat (breaks into many tiny droplets)
Term
Bile
Definition
Created in the liver, but stored and released by the gallbladder; releases into the small intestine where it emulsifies fat; eventually recycled in enterohepatic cycle (98%)
Term
Micelles
Definition
Tiny droplets of fat, surrounded by bile; the bile keeps the lipids suspended in water-based intestinal contents; also increasing surface area
Term
Absorption of Lipids
Definition
1. Large fat droplets enter small intestine after meal 2. Bile and lecithin emulsify fats into smaller particles 3. Lipase breaks down fat into fatty acids and monoglycerides 4. Monoglycerides and fatty acids are absorbed as micelles through the brush border and then re-formed into triglycerides 5. Short and medium chain fatty acids enter the blood stream (cardio system) 6. Triglycerides combine with cholesterol, protein, and phospholipids to form chylomicrons, which enter the lymphatic system
Term
Chylomicrons
Definition
Fatty acids > 12 carbons; released into the lymphatic system; transport lipids from small intestine to cells
Term
Very Low Density Lipoproteins
Definition
Transports lipids from the liver, through blood stream, to cell, becoming LDL
Term
Low Density Lipoprotein
Definition
Leftover lipoprotein transporting mostly cholesterol; oxidized and removed by WBC causing plaque on blood vessel walls
Term
High Density Lipoprotein
Definition
Removes cholesterol from cells and transports it to the liver; mostly produced in liver and intestine
Term
Triglyceride Energy
Definition
9 kcal / g; provide 30%-70% of energy during rest or light physical activity
Term
Adipose Cell
Definition
Contain 80% lipids, 20% water; can increase in weight 50 times
Term
Subcutaneous Fat
Definition
Insulates body from heat loss and cushions body against trauma
Term
Visceral Fat
Definition
Cushions vital organs
Term
Essential Fatty Acid Functions
Definition
Important structural components of cell walls; production of other important fatty acids; precursor for hormone-like (with 100 different functions) eicosanoids
Term
Sterol Function
Definition
Structural component of cell membrane; precursor for many regulatory substances (steroid hormones, estrogens, cortisone); precursor for bile
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