Nutrition exam 2
health benefits of insoluble fiber
-increases intestinal transit time -decreases constipation -lowers risk for diverticulitis and diverticulosis -lowers risk for colon cancer
Lipid digestion
1.) Mouth: enzyme lingual lipase breaks down medium and long-chain fatty acids. 2.) stomach: enzyme gastric lipase helps breakdown triglycerides into monoglycerides. about 30% of fat is digested in the stomach. 3.) small intestine: bile breaks down fat. enzymes Cholecystokinin-pancreozymin (CCK-PZ), cholesterol esterase and lipase. the bile acts as an emulsifier by breaking down fat globules, and increases surface area for enzymes to work. bile is created in the liver and stored in the gallbladder. CCK-PZ: enzyme made in the small intestine. stimulates the release of pancreatic lipase and bile. gallbladder contraction. cholesterol esterase: breaks down cholesterol esters. results in fatty acids and free cholesterol and is ready for other uses. Lipase: triglycerides break down into monoglycerides and free fatty acids. Phospholipids break down into glycerol and free fatty acids.
Describe chylomicrons
50% cholesterol composition changes with diet: high cholesterol meals= small dense chylomicrons. high fat meal: larger chylomicrons released into the lymph system lipase uses the triglycerides for energy in the body
Describe monosaccharides and give examples
A simple carbohydrate (simple sugars). Glucose, fructose, and galactose. Glucose is found in blood, fructose is found in fruit, galactose is found in milk sugar.
Describe disaccharides and give examples
A simple carbohydrate/simple sugar. a combination of two monosaccharides. Sucrose (glucose and fructose) is found in maple syrup, lactose (glucose and galactose) is found in milk products, and maltose (glucose glucose) is found in honey.
Soluble fiber
An indigestible polysaccharide. Dissolves in water, is metabolized by bacteria in the large intestine, provides fuel to cells, found in fruits, veggies, oat bran, chicory root fiber extract, and prebiotics.
Properties of carbohydrates
CHO, 4 calories per gram, our fuel from CHO is used as either glucose or glycogen. There are simple and complex carbohydrates
what is the difference between essential, non-essential, and conditionally essential amino acids?
Essential amino acids mean that we must get them from dietary sources while non-essential amino acids mean that our bodies can produce them. Conditionally essential amino acids are usually not essential, except in times of illness or stress.
describe the function of fatty acids (FAs)
FAs are the building blocks of lipids. They are components of triglycerides and phospholipids. FAs are a chain of carbons and hydrogens (carboxyl and methyl group). Fatty acids are energy sources and membrane constituents. they have biological activities that act to influence cell and tissue metabolism, function, and responsiveness to hormonal and other signals.
describe the process of protein digestion in the stomach
Gastrin, a hormone produced by the "G cells, " stimulates the parietal cells to secrete hydrochloric acid and stimulates the gastric chief cells to secrete pepsinogen. when pepsinogen and hydrochloric acid come into contact, pepsinogen is converted into pepsin. pepsin denatures proteins into polypeptides.
How are carbohydrates digested?
Location 1: Mouth with enzyme amylase that breaks down polysaccharides and disaccharides. Location 2: Stomach with no enzymes or actions involved. Location 3: Small intestine with enzymes pancreatic amylase, maltase, sucrase, and lactase. These enzymes break down disaccharides into monosaccharides. Location 4: Large intestine, where soluble fiber becomes fermented by gut bacteria.
describe the classification of fatty acids (FAs)
Long chain: over or equal to 12 carbons Medium: 6-10 carbons short: less than 6 carbons. Saturated fatty acids: No double bonds in carbon structure ( marbling in steak, butter, coconut and tropical oils) Monounsaturated FAs: One double bond in carbon structure (Olive and olive oil, avocado, almonds, peanut butter) Polyunsaturated FAs: More than one double bond in carbon structure (Corn oil, soy oil, hazelnuts, pumpkin seeds)
describe the function, classification and examples of triglycerides
Most common type of lipid (body and food) Made up of 3 fatty acids Glycerol backbone and carboxyl end Function: energy and insulation: subcutaneous fat layer under the skin's surface to help hold body temperature at a constant level. needed in absorption and transport: fat-soluble vitamins. Storage(adipose tissue) examples: butter, oils
food sources for monounsaturated fat
Olives, olive oil, canalo oil, peanut oil, nuts and avocados.
parts of a whole grain
Outside layer: The bran. The fiber-rich outer layer protects the seed and contains B vitamins and trace minerals. Middle layer: endosperm. contains carbohydrates and proteins Inner layer: The germ which is the small nutrient-rich core that contains antioxidants, vitamin E, B vitamins, and healthy fats.
describe the process of protein digestion and absorption in the small intestine
Polypeptides enter the small intestine. Cholecystokinin (CKK) is a hormone synthesized and released in the mucosal lining of the small intestine that stimulates the release of pancreatic and intestinal enzymes that further break down polypeptides into smaller amino acids. Amino acids are then absorbed through the intestinal lumen via special transport proteins into the portal vein and transported to the liver. The liver serves as the checkpoint for the final breakdown and distribution of amino acids. More than 90% of protein ingested does not get further broken down than amino acid monomers, and most are used to create new proteins in a process called protein turnover. when amino acids are broken down, nitrogen is released in the form of ammonia, converted to urea, and transported to the kidneys for elimination in urine.
Function of protein- structure
Proteins help to maintain the bodys structural integrity by helping to build important tissues including muscle, collagen, and skin. The body needs a regular source of dietary protein due to protein turnover. (ex: skin cells typically have a lifespan of about 30 days, while epithelial cells that line the GI tract only last 3-5 days.)
describe the concerns when consuming excess protein
Significantly exceeding the AMDR or the RDA can put stress on the kidneys, and can lead to kidney damage, especially in those with preexisting kidney conditions. high consumption of protein can increase losses of urinary calcium, increasing the risk for osteoporosis. high consumption of protein from animal sources significantly increases the risk of developing cardiovascular disease due to the saturated fat content that accompanies animal sources of protein. typically, overconsumption of protein comes from supplementation. it is not recommended for healthy individuals to consume more than 2g/kg per day.
What are the essential amino acids?
There are 9 essential amino acids, meaning we must get them from dietary sources. Valine, Isoleucine, Leucine, phenylalanine, tryptophan, threonine, methionine, lysine, and histidine.
What are the main functions of carbohydrates
They provide energy and fuel for the brain, regulate the digestive system, and influence blood sugar, 45-65% of our daily intake. Spares protein stores, creates fat, glucogenesis,
glucagon
a hormone made by the pancreas signals for the breakdown of glycogen increases blood sugar levels promotes glucogenesis
describe primary protein structure
a simple chain of amino acids
Describe the Mediterranean diet
about 40% of calories come from fat (olive oil as the main fat source) high intake from fruits, veggies, whole grains, beans, nuts and seeds minimally processed daily intake of small amounts of cheese and yogurt weekly intake of fish limited intake of eggs and red meat regular exercise moderate intake of wine
what is the basic structure of an amino acid
amino acids are composed of hydrogen, carbon, oxygen, and nitrogen. amino acid structure: Hydrogen, carboxyl, R-group (variant), and amino. amino acids are linked together by peptide bonds to form proteins. This bond is a link between an amino group and a carboxylic acid group, creating one molecule of water as its byproduct.
insoluble fiber
an indigestible polysaccharide. Does not dissolve in water, not metabolized by the bacteria in the large intestine, the dominant type of fiber found in foods, found in fruits, legumes, veggies, cereal grains, seeds of fruits, and bran layers of grains.
where do we find protein
animal sources and plant sources
type one diabetes, prevalence, treatment
autoimmune disease that destroys insulin-producing cells. About 5% of all cases of diabetes. treatment: always requires insulin, diet, exercise.
Atherosclerosis
build-up of fatty streaks in the arteries. fat, calcium, cholesterol, and other substances enlarge and harden arteries stiffen and narrow.
food sources for saturated fats
butter, marbling in steak, coconut oil and tropical oils.
Complementary proteins
can be combined to create a complete protein. (grains and legumes, grains and nuts = PB and bread, chips and hummus)
define protein-calorie malnutrition
chronic deficiency in protein and/or calories that leads to changes in body composition and function
what are the 4 types of lipoproteins?
chylomicrons, VLDL, LDL, HDL
describe polysaccharides and give examples
complex carbohydrates/sugars. 100s-1000s of glucose molecules. focusing on fiber, starch, and glycogen.
Describe oligosaccharides and give examples
complex carbohydrates/sugars. Made of 3-10 single sugar units. Cant be broken down. They act as prebiotics. examples are fructooligosaccharides and galactooligosaccharides.
vegan
consumes only plant foods.
define vegetarian
consumes plant foods, dairy and eggs.
define pescatarian
consumes plant foods, dairy, eggs, and fish.
complete proteins
contain all nine essential amino acids (animal sources, soy and quinoa)
food sources for polyunsaturated fat
corn and soy oil, hazelnuts, pumpkin seeds.
causes and consequences of protein denaturation
denaturation occurs via heat, acid, physical manipulation, and/or enzymes. Causes unwinding and unfolding of the tertiary structure irreversible (destroys biological structure)
describe the function, classification and examples of sterols
different from TAGs or phospholipids ring structure example: cholesterol, plant sterols plants and animals (only animals have cholesterol) function: anti-cancer, anti-inflammatory, anti atherogenicity, anti-oxidation
Diabetes mellitus
disease that impacts how the body uses blood glucose. There is type 1, type 2, and gestational diabetes.
Function of protein- enzymes
enzymes are proteins that catalyze specific reactions in the body. more than 100 chemical reactions occur in the human body every second, and most of them require enzymes. most enzymes can be used as a catalyst many times before ultimately being destroyed and rebuilt.
what are the 4 major types of lipids?
fatty acids (FAs) Triglycerides (TAGs) Sterols Phospholipids
how are carbohydrates transported
fructose and galactose are metabolized by the liver, and the liver converts it to glucose, and glucose is used by cells. glycogen is stored in the muscles and mostly the liver and excess glucose is converted to fat and stored in the adipose tissue.
Positive nitrogen balance
growth, pregnancy or healing
nitrogen equilibrium
healthy adults
implications and risk factors of cardiovascular disease (CVD)
heart disease is the number one leading cause of death in the U.S. disease of the heart and blood vessels. modifiable risk factors: physical inactivity, obesity, smoking, alcohol, co-morbidities, high intake of trans and saturated fats, low intake of fruits, veggies, whole grains.
hyperglycemia and hypoglycemia
high blood sugar low blood sugar
benefits of a vegetarian diet
high in fiber, vitamins, minerals, and phytonutrients that aid in disease prevention. low in saturated fat and cholesterol lower risk for hypertension, heart disease, cancer and type 2 diabetes.
HDL and influences of HDL
high-density lipoprotein 50% protein originates in the intestine and liver picks up cholesterol for delivery to the liver where it can be metabolized and excreted role in immunity blocks the oxidation of LDL "happy" cholesterol influences: omega three, olive oil, garlic, estrogen, exercise, mediterranean diet, resveratrol
insulin
hormone made by the pancreas allows glucose to enter the cells resulting in lower blood glucose levels promotes the synthesis of glycogen and fat
Concerns of a vegetarian diet
if not well planned, nutrients of concern include; iron, zinc, calcium, vitamin b12, vitamin d and omega-3 fatty acids. Protein bioavailability increases requirements to 1g/kg
How are carbohydrates absorbed?
in the hepatic portal vein glucose and galactose partake in active absorption that requires energy because it is moving against a gradient. Fructose is absorbed through facilitated absorption and diffusion of solutes.
type 2 diabetes, prevalence, treatment
insulin resistance leads to hyperglycemia. 37.3 million Americans have diabetes and 96 million Americans have prediabetes. Treatment: diet, exercise, oral medications, insulin
describe lipoproteins and function
interior is triglycerides exterior is phospholipids different proteins are on the outside of the lipoprotein hydrophilic casing allows the lipid to transfer through water fluids of the blood function: deliver lipids to cell via plasma and lymph
incomplete proteins
limited in at least one essential amino acid (gelatin, grains, legumes, nuts)
describe secondary protein structure
local folding of the amino acid chain into alpha-helices or beta-pleated sheets.
LDL and influences of LDL
low-density lipoprotein primary transporter of cholesterol to cells high amounts of LDL can cause plaque formation atherosclerosis can be oxidated- increased cholesterol build-up "lousy" cholesterol influences: vitamin E exercise supplementation: chitosan, avocado, red yeast extract, folic acid, flaxseed oil
food sources for trans fat
margarine, shortening, baked goods
Glycated hemoglobin (A1C Testing) with level percentages
measures blood glucose levels over the past few months Normal: below 5.7% Prediabetes: 5.7-6.4% Diabetes: 6.5% or higher
absorption of micelle
micelle enters the enterocyte micelle is broken down by specific mechanisms in the cell triglycerides, cholesterol esters, and phospholipids are combined to create a lipoprotein.
essential fatty acid food sources
omega 3: cold water fish, flaxseed, chia seeds, canola oil omega 6: eggs, peanut butter, corn oil, avocados.
health benefits of soluble fiber
protects against heart disease, manages cholesterol levels, manages blood sugar levels, adds bulk in stools, helpful in managing diarrhea.
function of protein- hormones
proteins are used for hormone synthesis. One example is the release of insulin to help control blood sugar levels. proteins are used in homeostatic processes such as acid-base balance and fluid balance.
function of protein- transport
proteins are used to transport nutrients in and out of cells. proteins also make up antibodies that help protect the body from foreign invaders.
describe the prep for absorption micelles
ready for absorption into the intestinal lumen. absorbed across the intestinal lumen via passive diffusion once the micelles are in the entrocyte they break apart again. they are broken down by different parts of the cell. Soft and rough ER.
how does what we eat affect our blood lipid levels
saturated fat: raises LDL dietary cholesterol: raises LDL (to a lesser extent) Trans fat: raises LDL and lowers HDL
define marasmus
significant lack of protein and energy, often accompanied by other nutrient deficiencies. A result of severe, chronic malnutrition.
Define Kwashiorkor
significant lack of protein and moderate energy deficit (most common in developing nations)
describe the functions of protein in the body
structure, enzymes, hormones, transport
how much protein do we need according to the RDA?
the RDA for healthy adults is 0.8g/kg per day
how much protein do we need according to the AMDR?
the acceptable macronutrient distribution range for protein is 10-35% of total calories.
describe tertiary protein structure
three-dimensional folding of the protein structure due to the side chain interactions. This formation determines the proteins shape and function.
describe optimal blood lipid levels
total cholesterol:less than 200mg/dL HDL: over 60mg/dL LDL: less than 100mg/dL triglycerides: less than 150mg/dL
describe the quaternary protein structure
two or more polypeptides folded together to form a larger protein
Negative nitrogen balance
untreated illness or injury (someone who is starving)
VLDL
very low density lipoprotein made in the liver and a small amount in the small intestine both exogenous and endogenous cholesterol contains apoprotein B-100 different sizes of VLDL through a series of protein exchanges, can become LDL
describe the function, classification and examples of phospholipids
water-soluble. they bind together to make cell membranes. they have a polar head (hydrophilic) and a non-polar tail (hydrophobic). functions: emulsifier: binding agent between lipid and water. examples; found in egg yolks (lecithin), bile, cell membranes, plasma.
