Final Exam (Cumulative) Flashcards
What is nutrition?
Nutrition is the science that studies food, and how food nourishes the body and influences health
stages of nutrition
ingestion digestion absorption transport metabolism excretion
Why is nutrition important?
because there is a relationship between nutrition and disease. Poor nutrition is associated with deficiency diseases such as scurvy and pellagra, plays a role in the development of cancer and osteoporosis, is associated with heart disease, stroke, and type 2 diabetes
Organic Nutrients
contain carbon, such as carbohydrates, lipids, proteins, and vitamins
inorganic nutrients
do not contain carbon, such as minerals and water
6 nutrients
carbs lipids proteins vitamins water minerals
macronutrients
provide energy/fuel for our bodies
required in large amounts
micronutrients
do not provide energy, facilitate the release of energy, assist in regulating body processes
required in smaller amounts
fat-soluble vitamins
stored in the human body, toxicity can occur from consuming excess amounts which accumulates in the body
Vitamins A, D, E, and K
water-soluble vitamins
not stored anywhere in the body, excess secreted in urine
toxicity generally only occurs by taking vitamin supplementation
Vitamins C and B-vitamins
Energy Yielding Nutrients – kcal/g for each
Carbohydrates - 4kcal/g
fat - 9kcal/g
protein - 4kcal/g
alcohol - not a nutrient - 7kcal/g
Dietary Reference Intakes (DRIs)
dietary standards for healthy people only. They aim to prevent deficiency disease and reduce chronic diseases.
Estimated Average Requirement (EAR)
supports a specific function in the body for half (50%) of the healthy population
Recommended Dietary Allowance (RDA)
Use the EAR as a base and include sufficient daily amounts of nutrients to meet the known nutrient needs of practically all healthy populations (98%)
Adequate Intake (AI)
Reflect the average daily amount of a nutrient that a group of healthy people consumes
Tolerable Upper Intake Level (UL)
Highest daily amount of a nutrient that appears safe for most healthy people and not be toxic
Estimated Energy Requirement (EER)
The average daily energy intake to maintain energy balance and good health for population groups
- defined by age, gender, weight, height, and level of physical activity
acceptable macronutrient distribution range (AMDR)
Represents the range of intake for energy nutrients that provide adequate energy and nutrients and reduce risk of chronic disease
3 useful tools for designing a healthy diet
food labels
the 2010 dietary guidelines for Americans
USDA food patterns: MyPlate
nutrient density
most nutrients for the least amount of calories
recommendations of the Dietary Guidelines for Americans
-balance calories to maintain weight
-consume fewer foods “of concern”
-consume more healthful foods and nutrients
follow healthy eating patterns
recommendations for MyPlate
make half of your grains whole vary your veggies focus on fruits get your calcium-rich foods go lean with protein
chronic disease
a disease characterized by a gradual onset and long duration, with signs and symptoms that are difficult to interpret and that respond poorly to medical treatment
examples: cancer and cardiovascular disease
how to evaluate if a person’s body weight is healthful
determining the body mass index (BMI)
assessing the pattern of fat distribution
measuring body composition
BMI
BMI=[weight (lbs)/height (inches)^2] * 703
Normal BMI: 18.5-25kg/m^2
fat patterns
apple or pear shaped
meausuring body composition
Underwater weighing skin fold measurements bioelectric impedence analysis dual-energy x-ray absorptiometry (DXA) Bod Pod
components of energy expenditure
Basal Metabolic Rate (BMR) or resting – 60-75%
Thermic Effect of Food (TEF) – 5-10%
Energy cost of physical activity – 15-35%
Anorexia Nervosa
- self-starvation leading to a severe nutrient deficiency, extreme drive for thinness
- 90-95% are young females, 5-20% die from complications within 10 years
Signs of Anorexia Nervosa
restrictive eating practice
fear of gaining weight
amenorrhea
Consequences of Anorexia Nervosa
energy and nutrient deficiency electrolyte imbalance cardiovascular problems gastrointestinal problems bone problems death
Bulimia Nervosa
- recurrent episodes of extreme overeating and compensatory behaviors (purging, excessive exercise) to prevent weight gain
- at least twice a week or 3 months
signs of bulimia
chronically inflamed and sore throat
swollen glands in neck and below the jaw
Consequences of bulimia
electrolyte imbalance
gastrointestinal problems
dental problems
Binge-Eating
extreme overeating without purging
After stressful events, more than twice a week
common in men
consequences of binge-eating
low self-esteem
avoidance of social contact
depression and negative thoughts
Night-Eating Syndrome
people who were not hungry during the day, but eat in the evening and night
depressed mood and insomnia
combination of eating disorder, sleep disorder, and mood disorder
alcohol abuse
the excessive alcohol consumption, whether chronically or occasionally, that results in distress, danger, or harm to one’s health functioning, or relationships
Include: alcohol hangover, reduced brain function, alcohol poisoning, increased risk for chronic disease, malnutrition, increased risk for traumatic injury, fetal and infant health problems
fatty liver (alcohol steatosis)
an early and reversible stage of liver disease
alcohol hepatitis
inflammation of the liver caused by alcohol, more severe
cirrhosis of the liver
end-stage liver disease, having significant abnormalities in liver structure and function
alcohol oxidation
first-pass metabolism: small amount of alcohol is oxidized in the stomach, before being absorbed into the bloodstream
alcohol then goes into the liver and is oxidized by liver enzymes (Alcohol dehydrogenase and aldehyde dehydrogenase)
Alcohol Dehydrogenase (ADH)
converts ethanol to acetaldehyde in the first step
Aldehyde Dehydrogenase (ALDH)
oxidizes acetaldehyde to acetate
Reduced cardiovascular risk from moderation
HDL increases
LDL decreases
Abnormal blood clot formation decreases
Moderation linked to increase risk of (3)
Breast cancer
Hypertension
Hemorrhagic Stroke
Concerns of moderation (3)
may increase total energy intake, increasing the risk of overweight or obesity
magnifies the effect of drug
increases the risk of GI bleeding, stomach bleeding, or liver damage
metabolic tolerance
the liver becomes more effective in its total breakdown of alcohol, BAC rises more slowly after drinking
functional tolerance
individuals show few signs of impairment/intoxication even at high BAC
hunger
a physiological sensation that prompts us to eat – nonspecific
appetite
a psychological drive to consume specific foods
how do hormones regulate appetite?
pancreatic hormones maintain the blood glucose levels
feeling full results from signals from the stomach and a rise in blood glucose
What does CCK do?
- stimulates secretion of pancreatic digestive enzymes
- stimulate gallbladder contraction
- slows gastric emptying
accessory organs of digestion (3)
gallbladder
pancreas
liver
digestion
large food molecules are broken down to smaller molecules, mechanically and chemically
absorption
process of taking these products through the intestinal wall
elimination
undigested portions of food and waste are removed from the body
segmentation
rhythmic contraction of circular muscles in the intestinal wall
mixes the chyme and enhances its contact with digestive enzymes and enterocytes
Four types of absorption
passive diffusion
active transport
facilitated diffusion
endocytosis (pinocytosis)
passive diffusion
nutrients simply pass through the enterocytes and into the bloodstream without the use of a carrier or energy
facilitated diffusion
requires a carrier protein
active transport
requires energy and a protein carrier to transport nutrients
endocytosis (pinocytosis)
active transport by which a small amount of intestinal contents is engulfed by the cell membrane and cells
The smallest molecules that make up carbohydrates are called __________________.
Monosaccharides (glucose, fructose, galactose)
Where does carbohydrate digestion occur and what enzymes are involved?
Mouth (begins) -- salivary amylase small intestine (mostly) -- pancreatic amylase
What type of diet causes ketosis?
A fasting diet
- fat breakdown during fasting forms ketones
- excess ketones increase the blood acidity and causes ketoacidosis
- sufficient energy from carbs prevents ketone production as an alternate energy source
hyperglycemia
high blood glucose
hypoglycemia
low blood glucose
may cause shakiness, sweating, anxiety, or weakness
What does insulin do?
- secreted by the beta cells of the pancreas
- stimulates glucose transport (carrier protein) to help take glucose from the blood across the cell membrane
- stimulates the liver to take up glucose and convert it to glycogen
What does glucagon do?
- secreted by the alpha cells of the pancreas
- stimulates the liver to convert glycogen to glucose
- stimulates gluconeogenesis, the production of glucose from amino acids
Type I Diabetes
accounts for 10% of all cases body is not able to produce enough insulin causes hyperglycemia insulin injections may be an autoimmune disease
Type II Diabetes
Accounts for 90% of all cases
insulin insensitivity – cells less responsive to insulin
causes: genetics, obesity, and physical inactivity
treatment: weight loss, healthy eating, regular exercise, and medication
food sources of saturated fats (8)
(solid at room temperature) cocunut oil palm kernel oil butter cheese whole milk cream lard beef fat
food sources of polyunsaturated fats (4)
(liquid at room temperature) cotton seed canola corn safflower oils
food sources of monounsaturated fats (4)
(liquid at room temperature) olive oil canola oil peanut oil cashew nuts
Food sources of trans fats(4)
hydrogenated veggie oils
margarine
baked goods
fried foods
Trans fats are not good for health. Why?
- Trans fat raises blood cholesterol levels and appear to change cell membrane function and the way cholesterol is removed from the blood
- increased risk of cardiovascular disease
essential fatty acids (EFAs)
must be obtained from food because the body cannot synthesize them
Two EFAs
Linoleic Acid
Alpha-linoleic acid
linoleic acid
omega-6 fatty acid
found in vegetable and nut oils, sunflower, corn, soy, and peanut oils
alpha-linoleic acid
omega-3 fatty acid
found primarily in dark green, leaky vegetables, flaxseeds and flaxseed oil, soybeans and soybean oil, walnuts and walnut oil, and canola oil
What compound secreted during digestion emulsifies fats? What organ makes and stores this?
Bile emulsifies fats into small droplets
Bile is produced in the liver, and stored in the gallbladder
What is a phospholipid?
- one of the three types of lipids that are found in foods, body cells, and tissues
- made up of a glycerol backbone + two fatty acids + a phosphate
- soluble in water
- transport fat in the bloodstream
- manufactured in our bodies
What transports fats into the enterocyte during digestion?
Micelles transport lipid digestion products to the enterocytes. Within entercytes, components from micelles reform triglycerides and are repackaged as chylomicrons for transport into the lymphatic system.
Micelle
spherical compound made up of bile salts and biliary phospholipids that can transport fats into the enterocyte for absorption
hydrophobic core and hydrophillic surface
chylomicron
a lipoprotein produced in the mucosal cell of the intestine
transports dietary fat out of the intestinal tract
monoacylglyceride
a glycerol molecule with one fatty acid still attached at the second carbon on the glycerol backbone
triclyceride
a molecule consisting of three fatty acids attached to a three-carbon glycerol backbone
The smallest molecules that make up proteins are called __________.
amino acids
essential amino acids
cannot be produced in sufficient quantities to meet physiological needs, must be obtained from food
What are the 9 essential amino acids?
Histidine Isoleucine Leucine Lysine Methionine Phenylalanine Theronine Tryptophan Valine
Limiting amino acid
essential amino acid that is missing or in the smallest supply
slows down or halts synthesis
What is a complete protein?
sufficient amounts of all nine essential amino acids
derived from animal and soy protein
soy protein sufficient for adults, but not infants
What are the functions of mucous in the stomach
to protect the stomach from being digested by the digestive juices
What does HCl activate in the stomach?
denatures protein strands and activates pepsin
Pepsin
an enzyme that breaks down proteins into short polypeptides and amino acids
What compound neutralizes stomach acid? What organ secretes this?
Bicarbonate neutralizes stomach acid and is produced in the pancreas
Intrinsic factor is needed to absorb which nutrient? Which cells in the stomach secrete this?
Parietal cells secrete intrinsic factor to absorb vitamin B12.
Which hormone triggers the stomach to release digestive juices? What is this digestive juice called?
Gastrin stimulates gastric glands to secrete gastric juice
Marasmus
disease caused by inadequate protein and energy intake
causes wasting and weakening of muscle, depressed metabolism, and a weakened immune system
Kwashiorkor
disease caused by adequate energy but inadequate protein intake
causes weight loss, muscle wasting, retarded growth, and edema
denaturation
the process by which protein uncoil and lose their shapte and function when they are exposed to heat, acids, bases, heavy metals, alcohol, and other damaging substances
transamination
the process of transferring the amine group from one amino acid to another in order to manufacture a new amino acid
Deamination
the process by which an amine group is removed from an amino acid
Describe a hydrolysis reaction
hydrolysis is a catabolic process by which large, chemically complex compound is broken apart with the addition of water
example of a hydrolysis reaction
pepsin is an enzyme that breaks down proteins into short polypeptides and amino acids via hydrolysis
Describe a condensation reaction
(dehydration synthesis)
an anabolic process that occurs when simple units combine to produce a larger, more complex molecule
water is released as a by-product
example of condentation reaction
dissacharides contain two molecules, as a result or condensation (lactose: one glucose molecule + one galactose molecule)
What is the starting molecule in the TCA cycle? What two compounds combine to form citrate?
Acetyl CoA = starting molecule
Acetyl CoA + Oxaloacetate = citrate
anabolism
the process of making larger, chemically complex molecules from smaller ones
- critical for growth, repair, maintenance,, and synthesis of chemical products essential for human functioning
- requires energy
catabolism
breakdown of larger, complex molecules to smaller, more basic ones
- begins with digestion (chemical reactions break down proteins lipids, and carbohydrates)
- old cells or tissues are broken down for repair or replacement;
- releases energy
Aerobic environment means that pyruvate will be converted to what molecule?
aerobic = without oxygen
pyruvate –> lactic acid
In the anaerobic environment, pyruvate will be converted to what molecule?
anaerobic = with oxygen
pyruvate –> acetyl CoA
ketogenic amino acid
the carbon skeletons are converted directly to acetyl CoA for the synthesis of free fatty acids
Glucogenic amino acid
the carbon skeletons are convered to pyruvate which is used to resynthesize glucose or is converted to acetyl CoA
Can glycogen released from the muscle raise your blood glucose?
Glycogen is stored in the liver and muscles
- liver glycogen is what maintains blood glucose levels and supports the needs of our cells
- the glycogen released from the muscles will not raise blood glucose levels. Instead it continually provides energy to the muscles during exercise
How can you restore glycogen in muscle?
By consuming diets high in carbohydrates
how do you determine protein requirement?
using nitrogen balance
what is the primary role of B-complex vitamins?
act as coenzymes in metabolic processes
What vitamins are parts of TPP, PLP, and NADP?
TPP - thiamin is required for formation
PLP - B6 is a part of it
NADP - niacin is essential for the formation
Ariboflavinosis
riboflavin deficiency
associated with protein-energy malnutrition and alcoholism
symptoms - sore throat, swollen mucous membranes
Pellagra
Niacin deficiency
symptoms: dementia, dermatitis, diarrhea (3 D’s)
Beriberi
thiamin deficiency
symptoms: muscle waste, nerve damage
Which of the B-vitamins are involved in metabolism of homocysteine? (5)
Folate Vitamin B12 Vitamin B6 Riboflavin Pantothenic Acid
What is choline? Is it a vitamin?
a vitamin-like substance important for metabolism, cell membranes, and neurotransmission
- necessary for synthesis of phospholipids
- accelerates synthesis and release of acetylcholine
deficiency of choline
liver damage due to accumulation of fat in the liver
toxicity of choline
fishy body odor vomiting excessive salivation sweating diarrhea low blood pressure
Chromium is involved in the cellular uptake of which molecule?
glucose
What hormones require iodine to be produced?
thyroid hormones
What are the two common extracellular ions and the two common intracellular ions?
extracellular - sodium, chloride
intracellular - potassium, phosphorus
What function does ADH have? What organ secretes it?
antidiuretic hormone: a hormone released to stimulate kidneys to reabsorb water and reduce production of urine
secreted by the pituitary gland
What function does aldosterone have? What organ secretes it?
signals kidneys to retain sodium and chloride
secreted by adrenal galnds
chloride is sourced mostly from what food product in our diet?
tables salt
processed foods typically contain what mineral to help preserve it?
Sodium
hypokalemia
low blood potassium
hyperkalemia
high blood potassium
hyponatremia
low blood sodium
hypernatremia
high blood sodium
Where is phosphorus stored? What can enhance the absorption of phosphorus?
phosphorus is stored mostly in bones and somewhat in the ICF
Vitamin D enhances the absorption
How are free radicals formed? How do antioxidants stabilize free radicals?
Free radicals are formed when oxygen has an odd number or unpaired electrons
-antioxidants stabilize free radicals by opposing oxidation. They work independently by donating their electrons or hydrogen molecules to free radicals to stabilize them and reduce the damage caused by oxidation.
What are the 4 main antioxidant micronutrients?
A
C
E
Selenium
Superoxide Dismutase
converts free radicals to less damaging substances, such as hydrogen peroxide
Catalase
removes hydrogen peroxide from the body by converting to water and oxygen
Glutathione peroxidase
removes hydrogen peroxide and stops the production of free radicals in lipids
Which food groups provide the majority of antioxidants in the diet?
Fruits, Vegetables, and whole grains
What are the functions of Vitamin E?
protects PUFA’s fatty cell components, and LDL’s from oxidation
normal nerve and muscle development
enhances immune system
added to oil-based foods and skincare products to reduce rancidity and spoilage
improves vitamin A absorption
Where is vitamin E stored?
90% in adipose tissue, 10% cell membranes
What function does Vitamin E have in the cellular membrane?
Vitamin E neutralizes free radicals in the cell membrane
In what forms is Vitamin E present in foods?
Vitamin E is present in the form of Alpha-tocopherol
What are some major functions of Vitamin C?
synthesizes: collage, DNA, bile, neurotransmitters, carnitine, hormones, and appropriate levels of thyroxine hormone.
antioxidant that protects LDL-cholesterol from oxidation, lungs from ozone and cigarette damage, white blood cells
reduces formation of nitrosamines
regenerates oxidized vitamin E
Enhances iron absorption
How does Vitamin C influence Vitamin E?
Vitamin C regenerates Vitamin E after it has been oxidized
What are toxicity and deficiency symptoms for vitamin C?
Toxicity – (only by supplements) nausea, diarrhea, nosebleeds, and abdominal cramps, iron accumulation
Deficiency – scurvy, bleeding gums, loose teeth, weakness, wounds that fail to heal, bone pain and fractures, diarrhea, depression, and anemia can resule
What circumstances increase your need for Vitamin C?
smoking (+35 mg/day)
Healing from a traumatic injury, surgery, burns
use of oral contraceptives
What is collagen?
Collagen is a protein found in all connective tissues of the body
-vitamin C is required for production
Vitamin A has a precursor, what is it?
Beta Carotene
What process helps increase beta-carotene bioavailability in food?
Bioavailability - the degree to which our bodies can absorb and utilize any given nutrient
beta-carotenes are absorbed better from cooked foods
What biological functions is Vitamin A involved in?
scavenges free radicals and protects LDL from oxidation essential for healthy vision cell differentiation sperm growth and fertilization bone growth
What does glutathione peroxidase requre as a cofactor?
Selenium
What does this enzyme system do? (glutathione peroxidase)
glutathione peroxidase removes hydrogen peroxide and stops the production of free radicals in lipids
explain the components of bone (4)
bone tissue, nerves, cartilage, connective tissue
factors that influence peak bone density
late pubertal age in boys late onset of menstruation in girls inadequate calcium intake low body weight physical inactivity during the pubertal years
How does the body regulate calcium levels in the blood?
- Low blood calcium levels stimulate the production of parathyroid hormone and activation of Vitamin D, which in turn causes an increase in blood calcium levels
- high blood calcium levels stimulate the secretion of calcitonin, which in turn causes a decrease in blood calcium levels
Sources of vitamin K
green leafy vegetables, vegetable oils
vitamin K synthesis
by bacteria in the large intestine
function of vitamin K
to serve as a coenzyme during the production of specific proteins (osteocalcin and Matrix Gla protein) that play important roles in the coagulation of blood and in bone metabolism
What factors influence magnesium absorption?
Kidney regulate blood magnesium levels
Dietary protein enhances absorption and retention
Phytates and fiber decrease the absorption
Flurosis
abnormally high intake of fluoride
teeth become more porous, and become stained and pitted
Skeletal health issues associated with Vitamin D deficiency
rickets in children
osteomalacia in adults
How is vitamin D produced?
synthesized by the body from exposure to UV rays from the sun
Food sources of Vitamin D?
fortified foods - milk, soy, cereal products
cod liver oil, fatty fish (salmon mackerel sardines)
Osteoporosis
a disease characterized by:
low bone mass
deterioration of bone tissue
fragile bones leading to bone-fracture risk
compression of bone
shortening and hunching of the spine (kyphosis)
components of blood (4)
Erythrocytes
Leukocytes
Platelets
Plasma
Erythrocytes
red blood cells transport oxygen through the body
Leukocytes
white blood cells are key to our immune system
Platelets
cell fragments assist in blood clotting
Plasma
fluid portion of the blood maintains adequate blood volume
Iron absorption
iron goes from the stomach, to the small intestine, from there it goes to the colon and the enterocyte, and then into the blood
vitamin B12 absorption
B12 goes from the stomach to the small intestine, into the enterocyte, and then into the blood
food sources of vitamin B12
found primarily in dairy products, eggs, meats, poultry, fish, and shellfish
heme iron
only in animal based foods
meats, poultry, fish, clams, oysters, liver, enriched or fortified cereals and breads
non-heme iron
animal and plant based foods
What digestive conditions cause greater absorption of iron? (3)
Meat factor
Stomach Acids
Vitamin C
What are the storage (2) and transport (1) molecules for iron?
Storage – ferritin and homosiderin
Transport – transferrin
How is zinc absorbed and transported?
inhibit absorption
-high non-heme iron intake
-phytates and fiber (whole grains, beans)
enhance absorption
-animal-based protein
absorbed- from the lumen of the intestine into the erythrocytes through both active transport by carriers and simple diffusion
copper toxicity and deficiency
toxicity: abdominal pain, nausea, diarrhea, vomiting, liver damage (Wilson disease)
deficiency: anemia, reduced white blood cells, osteoporosis, in children–bone demineralization
folate toxicity and deficiency
toxicity: intestinal pain, nausea, vomiting
deficiency: macrocytic anemia, elevated homocysteine, neural tube defects
iron toxicity
nausea
vomiting
diarrhea
hemochromatosis
iron deficiency (3 stages)
stage 1: decreased iron stores, reduces ferritin level, no physical symptoms
stage 2: decreased iron transport, reduced transferrin, reduced production of heme, physical symptoms include reduced work capacity
stage 3: decreased production of normal red blood cells, reduced production of heme, inadequate hemoglobin to transport oxygen, symptoms include pale skin, fatigue, reduced work performance, impaired immune and cognitive functions
vitamin B12 toxicity and deficiency
toxicity: no known adverse effects
deficiency: dietary insuffiency or reduced absorption, gastrointestinal and neurologic effects, pernicious anemia
what cells function as part of the immune system?
RBCs- transport oxygen
WBCs- key to our immune function and protect us from infection and illness
Platelets: cell fragments that assist in the formation of blood clots
Plasma: fluid portion of blood and is needed to maintain adequate blood volume so blood flows easily throughout the body
non-specific immune cells
body’s primary defense against microbes, airborne particles, venom, and ingested toxins
specific immune cells
directed against antigens
Describe immunocompetence and how it relates to diet
the body’s ability to adequately produce an effective immune response to an antigen
-decreased immunocompetence is a sensitive indicator of reduced nutritional status
