Midterm Flashcards
substances in food that humans need to live and grow. They provide energy and structure to the body and regulate body processes
nutrients
nutrients that the body cannot make itself and, as a result, humans must consume to maintain health
essential nutrients
a unit of measure used to express the amount of energy provided by food. 1 kilocalorie = 1 Calorie = 1000 calories
calories
long-term diseases such as heart disease or obesity that often negatively affect physical and mental health and increase risk of early mortality
chronic diseases
a measure of the nutrients provided by a food relative to its calorie content
nutrient density
foods to which one or more nutrients have been added
fortified foods
products sold to supplement the diet; may include nutrients (vitamins, minerals, amino acids, fatty acids) enxymes, herbs or other substances
dietary supplements
6 classes of nutrients
carbohydrates lipids proteins water vitamins minerals
needed in large amounts
macronutrients
macronutrients
carbohydrates
lipids
proteins
water
needed in small amounts
micronutrients
micronutrients
vitamins
minerals
substances that contain carbon bonded to hydrogen in their molecular structure
organic compounds
a class of nutrients that includes sugars, starches and fibres. Chemically they all contain carbon, hydrogen and oxygen, in the same proportions as in water (H2O)
carbohydrates
a type of carbohydrate that connot be digested by human enzymes
fibre
a class of nutrients often referred to as fats. Chemically, they contain carbon, hydrogen and oxygen and most do not dissolve in water
lipids
a type of lipid that is found in the diet and in the blood. It is an essential component of every cell and can be used to form hormones, bile and vitamin D. High blood levels of it can increase the risk of heart disease
cholesterol
lipids that contain no double bonds in their structure. They are most abundant in solid animal fats and may be associated with an increase risk of heart disease
saturated fats
lipids that contain one or more double bonds in their structure. They are most abundant in plant oils and may be associated with a reduced risk of heart diseas
unsaturated fats
all proteins are made up of these usits
amino acids
organic molecules that are needed in small and amounts to maintain health. they are fat and water soluble
vitamins
essential elements that can be found on the periodic table
minerals
kilocalories in fats, carbohydrates and proteins
9 kcal/g
4 kcal/g
4 kcal/g
substances found in plant foods that are not essential nutrients but may have health promoting properties
phytochemicals
foods that have health promoting and/or disease preventing properties beyond basic nutritional functions
functional foods
a condition resulting from an energy or nutrient intake either above or below that which is optimal
malnuitrition
specific segments of DNA that are responsible for determining specific inherited traits
genes
the study of how diet affects our genes and how individual genetic variation can effect the impact of nutrients or other food components on health
nutritional genomics or nutrigenomics
proposed explanations for an observation or a scientifc problem that can be tested through experimentation
hypothesis
formal explanations of an observed phenomenon made after a hypothesis has been repeatedly supported and tested through experimentation
theories
the branch of science that studies health and disease trends and patterns in populations. In these studies, observations are made without the manipulation of variable
epidmiology
in a scientific experiment, the group of participants who undergo the treatment being tested
experimental group
in a scientific experiment, the group of participants used as a basis of comparison. Thay are similar to the participants in the experimental group but do not receive the treatment being tested
control group
energy yielding nutrients
carbohydrates
lipids and proteins
overdose of iron
can cause liver failure
too much vitamin B6
can cause nerve damage
first food guidelines that Canada released that provided info on amount of essential nutrients need to meet the needs of most Canadians
recommended nutrient intakes (RNIs)
an individual’s health, as it is influenced by the intake and utilization of nutrients
nutritional status
a set of scientifically based reference values for the amounts of energy, nutrients and other food components in the diet that are recommended the be consumed to reduce chronic disease risk, promote general health and minimize symptoms of deficiency
dietary reference intakes (DRIs)
nutrient intakes estimated to meet the needs of 50% of the healthy individuals in a given gender and life-stage group
estimated average requirements (EARs)
nutrient intakes that are sufficient to meet the needs of almost all healthy people in a specific gneder and life-style group
recommended dietary allowances (RDAs)
nutrient intakes that should be used as a goal when no RDA exists. these values are an approximation of the nutrient intake that sustains health
adequate intakes (AIs)
maximum daily intake levels that are unlikely to pose risks of adverse health effects to almost all individuals in a given gender and life-stage group
tolerable upper intake levels (ULs)
average energy intake values predicted to maintian body weight in healthy individuals
estimated energy requirements (EERs)
healthy ranges of intake for carbohydrate, fat and protein, expressed as percentages of total energy intake
acceptable macronutrient distribution ranges (AMDRs)
acceptable macronutrient distribution ranges for protein, carbohydrates and fat
protein → 20-35%
carbs → 45-65%
fat → 20-35%
vegetables and fruit
females → 7-8
males → 8-10
eat at least one dark green and one orange vegetable each day
grain products
females → 6-7
males → 8
make at least half of your grain products whole grain each day
milk and milk alternatives
females and males → 2
meat and meat alternatives
females → 2
males → 3
have meat alternatives such as beans, lentils and tofu often
eat at least two Food Guide Servings of fish each week
oils and fats
2 to 3 tbsp of unsaturated fat
critical for maintaining appropriate blood pressure and helps regulate blood temperature
water
recommended for women
multivitamins containing iron
400 milligrams of folic acid
recommended for over 50
increased need for vitamin D
mandatory information on food labels (5)
Statement of identity
Net contents of package
Name and address of manufacturer, packer and distributor
List of ingredients (listed in descending order by weight)
Nutrition information (nutrition facts panel)
accurately reflects the weight, volume, measure or numerical count of the product and it must now be expressed in metric untis
net quantity declaration
a reference value for the intake of nutrients used on food labels to help consumers see how a given food fits into their overall diet
daily value
statements that highlight specific characteristics of a product that might be of interest to consumers
nutrient content claims
refers to a relationship between a nutrient, food, food component or dietary supplement and the reduced risk of a disease or health-related condition
diet related health claims
states the well-known beneficial effects of a food or a food constituent on the normal function of the body
function claims
states the associations between food or its components with a reduced risk of a nutritional-related disease
disease-reduction claims
multivitamin pills, herbal remedies, probiotics and essential fatty acid and amino acid isolates that require a licence to be sold in Canada
natural health products
how the nutritional status of an individual is determined (3)
analyze nutrient intake
evaluate physical health
consider medical history
natural health product labels must contain (4)
Product license number
List of medical and non-medical ingredients
Description of recommended does
Any necessary cautionary statements
the smallest units of an element that retain the poperties of the element
atoms
units of two or more atoms of the same or different elements bonded together
molecules
the basic structural and functional units of living things
cells
what cells similar in structure and function form
tissue
4 types of tissue
muscle
nerve
epithelial
connective
discrete structures composed of more than one tissue that perform a specialized function
organs
chemical messengers that are produced in one location in the body, released into the blood and travel to other locations, where they elict responses
hormones
circulatory system (2)
heart, blood vessels
transportation of blood that carries oxygen, nutrients and wastes etc.
digestive tract (9) (2)
digestive tract (mouth, pharynx, esophagus, stomach, intestines), accessory organs (salivary glands, pancreas, liver, gallbladder)
digestion, absorption of meals
endocrine system (5) (2)
pituitary, adrenal, thyroid, pancreas and other ductless glands
production and release of hormones (chemical messengers)
lymphatic system (3) (3)
lymph nodes, lymph vessels, spleen
drainage, imunity, transportation of fat-soluable nutrients
nervous system (4) (2)
sensory receptors, nerves, spinal cord, brain
generation of response to stiuli from external and internal environments, transission of impulses to activate muscles and glands integration of activities of other systems
the process by which food is broken down into components small enough to be absorbed into the blood stream
digestion
the process of taking substanes from the gastrointestinal tract into the interior of the body
absorption
body waste, including unabsorbed food residue, bacteria, mucus and dead cells, which is eliminated from the gastrointestinal tract by way of the anus
feces
chews food and mixes it with saliva
mouth
produces saliva, which contains a starch-digesting enxyme
salivary glands
swallows chewed food mixed with saliva
pharynx
moves food to the stomach
esophagus
churns and mixes food; secretes acid and a protein-digesting enzyme
stomach
makes bile, which aids in digestion and absorption of fat
liver
releases bicarbonate to neutralize intestinal contents; produces enzymes that digest carbohydrate, protein and fat
pancreas
stores bile and releases it into the small intestine when needed
gallbladder
absorbs nutrients into blood or lymph; most digestion occurs here and is about 6 m long
small intestine
absorbs water and some vitamins and minerals; home to intestinal bacteria; passes waste material and is 1.5 m long
large intestine
opens to allow waste to leave the body
anus
a hollow tube about 9 m long, running from the mouth to the anus
gastrointestinal tract
inside hole of the gi tract
lumen
lines lumen and contributes to both secretion and absorption
layer of mucosal cells called mucosa
a vicious fluid secreted by glands in the digestive tract and other parts of the body it lubricates, moistens and protects cells from harsh environments
mucus
protein molecules that accelerate the rate of specific chemical reactions without being changed themselves
enzymes
a reaction that uses water to break down larger molecules into their structural units
hydrolysis
a reaction in which two structural units combine to create a larger molecule, typically resulting in the loss of a water molecule
condensation
a watery fluid that is produced and secreted into the mouth by the salivary glands. It contains lubricants, enzymes, and other substance
saliva
enzyme that breaks starch molecules into shorter carbohydrate chains
salivary amylase
enzyme that initiates the digestion of fat
lingual lipase
using chemicals such as enzymes to help break down food
chemical digestion
mass of chewed food mixed with saliva
bolus
a piece of elastic connective tissue that covers the opening to the lungs during swallowing
epiglottis
coordinated muscular contractions that move material through the GI tract
peristalsis
a layer of muscle that encircles the tube of the digestive tract and acts as a valve
sphincter
the bolus is mashed and mixed with highly acidic stomach secretions to form a liquid food mass
chyme
produced by gastric glands in the pits that dot the stomach lining and causes chemical digestion in the stomach. it is a mixture of water, mucus, hydrochloric acid and pepsinogen
gastric juice
an inactive form of the protein-digesting enzyme pepsin
pepsinogen
three segments of small intestine and their lengths
duodenum (25-30 cm)
jejunum (2-3 m)
ileum (2-4 m)
coordinated, periodic muscular contractions that aid in digestion and absorption, but do not significantly propel chyme forward
segmentation
finger-like projections that cover the entire inner surface of the small intestine
villi
a small blood vessel in a villus
capillary
a small lymph lymph vessel in a villus
lacteal
tiny projections of the mucosal cell membrane on a villus
microvilli
secreted by the pancreas and contains digestive enzymes and bicarbonate
pancreatic juice
help regulate pH
bicarbonate
when amino acids and fats enter the small intestine this hormone is released. it delays stomach emptying and regulates the secretion of digestion promoting molecules into the small intestine
cholecystokin (CCK)
an enzyme that continues the job of breaking down starches into sugars
pancreatic amylase
protein-digesting enzymes that break protein into shorter and shorter chains of amino acids
proteases
fat-digesting enzymes that break down fats into fatty acids, glycerol and monoglyecerides
lipases
A digestive fluid made in the liver and stored in the gallbladder that is released into the small intestine, where it aids in digestion and absorption
bile
net movement of substances from an area of higher concentration to an area of lower concentration
diffusion
the unassisted diffusion of a substance across the cell membrane
simple diffusion
the unassisted diffusion of water across the cell membrane
osmosis
the assisted diffusion of a substance across the cell membrane with the help of a protein carrier
facilitated diffusion
the transport of substances across a cell membrane with the aid of a protein carrier and the expenditure of energy
active transport
4 parts of the large intestine
ceacum
colon
rectum
anus
connects small intestine to colon and is attachment point to the appendix
ceacum
largest section of the large intestine and composed of the ascending, transverse, descending and sigmoid
colon
temporary holding place for feces
rectum
breaks down unabsorbed portions of food producing nutrients that can be used by the microbiota or are absorbed into the body
intestinal microbiota
living organisms found in food that contributes to intestinal health
probiotic
dietary fibre that promotes the growth of healthy intestinal bacteria
prebiotic
a substance found on disease-causing agents that identifies them as foreign from the body’s cells. When introduced into the body, it stimulates an immune response
antigen
first type of white blood cells that comes to the body’s defense by eliminating or “eating” the micro-organisms
phagocytes
white blood cells that destroy foreign micro-organisms by binding to them
lymphocytes
proteins, released by a type of lymphocyte, that interact with antigens and promote the removal of foreign invaders from the body
antibodies
a substance that causes an allergic reaction
allergen
a condition in which the protein gluten triggers an immune system response that damages or destroys the villi of the small intestine
celiac disease
a burning sensation in the middle chest caused when acidic stomach contents leak back into the esophagus
heartburn
gastroesophageal reflux
a chronic condition in which acidic stomach contents leak into the esophagus, causing pain and damaging the esophagus
gastroesophagael reflux disease (GERD)
open sores in the lining of the stomach, esophagus or upper small intestine. caused by GERD, misuse of medications and most commonly, by infection with the bacterium helicobacter pylori
peptic ulcers
clumps of solid material that accumulate in either the gallbladder or the bile duct
gallstones
frequent watery stools that occur when material passes to quickly through colon or intestinal cells draw excess water into lumen. caused by infections, irritants, passage of undigested material into the large intestine, medications or chronic intestinal illness
diarrhea
hard, dry stools that are difficult to pass caused by diet low in fibre and fluids, lack of exercize, weakening of muscles of large intestine or medications
constipation
small, thin-walled blood vessels through which blood and the body’s cells exchange gases and nutrients
capillaries
lymph vessels in the villi of the small intestine that pick up particles containing larger products of fat digestion
lacteals
blood vessels that transport blood and dissolved substances toward the heart
veins
blood vessels that transport blood and dissolved substances away from the heart
arteries
the smallest arteries
arterioles
the smallest veins
venules
once in the capillaries, absorbed nutrients first travel to the liver vis this
heptic portal vein
the chemical reactions that break down molecules to provide energy and those that synthesize larger molecules requiring energy
metabolism
when larger molecules are synthesized and new bonds are formed
anabolism
breakdown of moelcuels
catabolism
series where many reactions of metabolism occur
metabolic pathways
cell organs that are responsible for breaking down molecules to release energy
mitochondria
a high-energy molecule that the body uses to power activities that require energy
ATP (adenosine triphosphate)
uses oxygen to convert glucose, fatty acids and amino acids into carbon dioxide, water and usable energy (ATP). occurs in the mitochondria
cellular respiration
extracting energy from glucose steps
step 1: glycolysis
step 2: the breakdown of pyruvate
step 3: the citric acid cycle
step 4:the electron transport chain
occurs in cytoplasm of cell
doesn’t require oxygen
6-carbon glucose is broken down into 2 molecules of 3-carbon pyruvate
produces minimal ATP
step 1: glycosis
how pyruvate is broken down depends on whether oxygen is present
a) when oxygen is absent, pyruvate is converted into lactate and ATP
b) when oxygen is present, pyruvate is converted into acetyl CoA (requires coenzyme A)
step 2: breakdown of pyruvate
a four-carbon sugar
oxaloacetate
a six-carbon sugar
citrate
begins when acetyl CoA combines with oxaloacetate to form citrate
leads to production of CO2, water and the capture of energy in GTP
two important electron carriers (NADH+, H+ and FADH2) are also there to capture electrons and carry them to step 4
step 3: the citric acid (kreb’s) cycle
at the mitochondrial membrane, electron carriers donate electrons to various donor and acceptor molecules located in the membrane
a series of oxidation (loss of electrons) and reduction (gain of electrons) reactions occurs
as bonds are broken and energy is released, it is captured by 30 or more molecules of ATP
step 4: the electron transport chain
fats must first be broken down into their two components (glycerol and 3 fatty acids)
can only proceed through citric acid cycle is there are sufficient carbohydrates present to form oxaloaxcetate
extracting energy from fat
fats first needs to be broken down into two-carbon structures which requires oxygen and coenzyme A to produce the two-carbon molecule acetyl CoA
beta oxidation
removal of the nitrogen-containing amine group from a molecule
deamination
after an amino acid has been deaminated, its remaining structure can enter cellular respiration at various stages, depending on what the remaining structure is
extracting energy from protein
eaten as found in nature or with only minimal processing
unrefined foods
refers to foods that have undergone processing to remove the coarse parts of the original food
refined
who-grain products include (3)
germ
bran
endosperm
primarily starch. also contains protein, vitamins and minerals
endosperm
fibre, higher in vitamins and minerals
bran
source of oil, rich in vitamin E
germ
the addition of specific amounts of thiamin, riboflavin, niacin and iron to refined grains. Since 1998, folic acid has also been added to enriched grains
enrichment
the addition of nutrients to foods
fortification
energy with few additional nutrients
empty calories
the smallest unit of a carbohydrate molecule. contain carbon, hydrogen and oxygen in the same two-to-one portion as water
sugar units
a carbohydrate made up of a single sugar unit
monosaccharide
a carbohydrate made up of two sugar units
disaccharide
a carbohydrate made up of two or more sugar units linked together
polysaccharide
monosaccherides and disaccherides
simple carbohydrates
three most common monosaccherides in our diet that each contain six carbon, 12 hydrogen and six oxygen atoms
glucose
fructose
galactose
a six-carbon monosaccheride that is the primary form of carbohydrate used to provide energy in the body. the brain and red bloods cells specifically require it
glucose
blood sugar
most common disaccherides
maltose
sucrose
lactose
polysaccherides that are generally not sweet tasting
complex carbohydrates
the storage form of carbohydrate in animals and plants, made up of many glucose molecules linked together in a highly branched structure
glycogen
a carbohydrate found in plants, made up of many glucose molecules linked in straight or branched chains
starch
a type of complex carbohydrate that cannot be broken down by human digestive enzymes still provides approximately 2-3 kcal/g
fibre
dissolves in water or absorbs water and can be broken down by intestinal microbiota. It includes pectins, gums and some hemicelluloses. binds cholesterol containing compounds and also regulates blood sugar
soluble fibre
does not dissolve in water and cannot be broken down by bacteria in the large intestine. Insoluble fibre includes cellulose, some hemicelluloses and lignin, which can all be found in the cell walls of plants. speeds passage through intestines, binds toxic waste products and promotes regular bowel moevements
insoluble fibre
disaccherides and complex carbohydrates must be digested into these before they can be absorbed
monosaccherides
the inability to digest lactose due to a reduction in the levels of the enzyme lactase
lactose intolerance
short carbohydrate chains containing 3 to 10 sugar units
oligosaccherides
starch that escapes digestion in the small intestine
resistant starch
the rate, magnitude and duration of the rise in blood glucose that occurs after food is consumed
glycemic response
a hormone made in the pancreas that allows glucose to enter cells, where it can stimulate the synthesis of fat and liver and muscle glycogen
insulin
a hormone made in the pancreas that raises blood glucose levels by stimulating the breakdown of liver glycogen and the synthesis of glucose
glucagon
an anaerobic metabolic pathway that splits glucose into two three-carbon pyruvate molecules; the energy released from one glucose molecule is used to make two molecules of ATP
glycolysis
metabolism in the absence of oxygen
anaerobic metabolism
metabolism in the presence of oxygen. It can completely break down glucose to yield carbon dioxide, water and energy in the form of ATP
aerobic metabolism
acidic molecules formed when the body has insufficient carbohydrate to completely metabolize the acetyl CoA produced from fatty acid breakdown
ketones or ketone bodies
a disease characterized by elevated blood glucose due to either insufficient production of insulin or decreased sensitivity of cells to insulin
diabetes mellitus
the form of diabetes caused by autoimmune destruction of insulin-producing cells in the pancreas, usually leading to absolute insulin deficiency
type 1 diabetes
a disease that results from immune reactions that destroy normal body cells
autoimmune disease
the form of diabetes characterized by insulin resistance and relative (rather that absolute) insulin deficiency
type 2 diabetes
a condition when glucose levels are above normal byt not high enough to be diagnosed as diabetes
prediabetes
an elevation of blood sugar that is first recognized during pregnancy
gestational diabetes
early symptoms of diabetes (4)
frequent urination
excessive thirst
blurred vision
weight loss
long term complications of diabetes
damage to heart, blood vessels, kidneys, eyes and nerves
abnormally low blood glucose levels
hypoglycemia
occurs in response to the consumption of high carbohydrate foods
reactive hypoglycemia
a condition in which outpouches (or sacs) form in the wall of the large intestine
diverticulosis
carbohydrate recommendations (2)
RDA → 130 g per day
AMDR → 45-65% of total calorie intake
AI for fibre
females → 25 g per day
males → 38 g per day
a group of organic molecules, most of which do not dissolve in water. They include fatty acids, triglycerides, phospholipids and sterols
lipids
the major form of lipids in food and the body; consist of three fatty acids attached to a glycerol molecule.
triclycerides
molecules made up of a chain of carbons linked to hydrogen, with an acid group at one end of the chain
fatty acids
types of lipids whose structure includes a phosphorus atom. not essential to diet and allow water and fat to mix
phospholipids
types of lipids with a structure composed of multiple chemical rings. not essential to diet
sterols
a fatty acid in which the carbon atoms are bonded to as many hydrogen atoms as possible; it therefore contains no carbon - carbon double bonds. solid at room temperature
saturated fatty acids
a fatty acid that contains one or more carbon-carbon double bonds; may be either monounsaturated or polyunsaturated. liquid at room temperature
unsaturated fatty acids
fatty acids that must be consumed in the diet because they cannot be made by the body or cannot be made in sufficient quantities to meet needs
essential fatty acids (EFAs)
regulatory molecules that can be synthesized from omega-3 and omega-6 fatty acids
eicosanoids
dry scaly skin, liver abnormalities, poor healing, impaired vision and growth in infants
symptoms of EFA deficiency
a process whereby hydrogen atoms are added to carbon-carbon double bonds of unsaturated fatty acids, making them more saturated. can increase shelf life
hydrogenation
a sterol, produced by the liver and consumed in the diet, which is needed to build cell membranes and make hormones and other essential molecules
cholesterol
LDL cholesterol
bad cholesterol
HDL cholesterol
good cholesterol
the role of bile in fat digestion
emulsifier
particles that are formed in the small intestine when the products of fat digestion are surrounded by bile. They are an aggregation of lipid molecules as a droplet that facilitates the absorption of lipids
micelles
particles that transport lipids in the blood
lipoproteins
lipoproteins that transport lipids from the mucosal cells of the small intestine and deliver triglycerides to other body cells. it ends up in the liver where it is broken down
chylomicrons
an enzyme, found in adipose tissue, the heart and muscles, that promotes the uptake of triglycerides from chylomicrons and other lipoproteins into body cells
lipoprotein lipase
transports lipids synthesized by the liver
very low density lipoproteins (VLDLs)
lipoproteins that transport cholesterol to cells. They are not consumed from the diet; they are made by the body
low-density lipoproteins (LDLs)
lipoproteins that pick up cholesterol from cells and transport it to the liver so that it can be eliminated from the body. They are not consumed from the diet; they are made by the body
high-density lipoproteins (HDLs)
the fat that lies under the skin and around internal organs
adipose tissue
a type of cardiovascular disease that involves the buildup of fatty material in the artery walls
atherosclerosis
cholesterol-rich material that is deposited in the arteries of individuals with atherosclerosis. It consists of cholesterol, smooth muscle cells, fibrous tissue and eventually calcium. formation is driven by inflammation
atherosclerotic plaque
substances that are able to neutralize reactive oxygen molecules and thereby prevent cell damage
antioxidants
fat and cholesterol recommendations
DRI fat intake → 20-35% of calories
