Nutritional Biochem 1 Flashcards
powerhouse
Mitochondrion
DNA and RNA synthesis
Nucleus
protein synthesis
Ribosomes
Rough ER
protein synthesis
Smooth ER
lipid synthesis
Smooth ER in muscle cells;
site of Ca pump (muscle contraction)
Sarcoplasmic reticulum
Secretory vesicles; packaging of proteins
Golgi apparatus
catabolic functions:
◦Phagocytosis
◦Autolysis
◦Bone resorption
Lysosomes
oxidation and detoxification reactions
Peroxisomes
cell reproduction
Centrioles
___ is made up of nutrients.
Food
___ are the very essence of food.
Nutrients
Breaking down of food into absorbable form
Digestion
Absorbable form of Carbohydrates
Glucose (Sugars)
Absorbable form of Protein
Amino acids
Absorbable form of Fats
Fatty acids and glycerol
A continuous, coiled, hollow, muscular tube between the mouth and the anus, including the organs through which food passes for digestion and elimination as waste
Gastro Intestinal Tract (GIT)/ Alimentary Canal
Primary Roles of the GI Tract
- Receipt, maceration, & transport of ingested substances
- Secretion of digestive enzymes, acid, mucus, bile and other materials
- Digestion of ingested foodstuffs
- Absorption and transport of products of digestion
- Transport, storage and excretion of waste products
also called PHYSICAL change
Chewing/ Mastication
Swallowing
Elimination
MECHANICAL CHANGE
- Breakdown to simpler components with action of enzymes
- Absorption, metabolism and utilization
CHEMICAL CHANGE
Oral cavity; a mucous
membrane-lined cavity
Mouth
- muscular tube located in the neck, lined with mucous membrane.
- connects the nose and mouth with trachea (windpipe) and esophagus
- serves as a passageway for both air and food
Pharynx
Gullet; runs from the pharynx to the stomach (25 cm)
A passageway that conducts food to the stomach
Esophagus
C-shaped organ on the left side of the abdominal cavity (25 cm long)
Acts as a temporary storage tank for food and site for food breakdown
Stomach
result when the normal defense and repair system that protect mucosa of GI tract is disrupted.
Peptic Ulcers
Body’s major digestive and absorptive organ. extending from the pyloric sphincter to the ileocecal valve.
Small Intestine
what is the length of the small intestines?
2-4 m
what are the 3 subdivisions of he small intestines?
duodenum, jejunum, ileum
what is the length of the duodenum?
25 cm
what is the length of the jejuum?
2.5 m
what is the length of the ileum?
3.6 m
Wrinkled into hundreds of folds
VILLI
A villus-composed of hundred of cells covered with
MICROVILLI/brushborder
Ileocecal sphincter regulates the flow of material from the ileum, the last segment of the small intestine, into the \_\_\_\_.
cecum
The duodenum receives secretions from the gallbladder via the _____.
common bile duct.
The pancreas releases its secretions into the _____ _____, which eventually joins the
common bile duct.
pancreatic duct
regulates the flow of these secretions into the duodenum.
sphincter of Oddi
A tube which extends from the ileocecal sphincter to the anus.
Dry out indigestible food residue by absorbing water, and to eliminate residues as feces
Large Intestines/ Colon
what is the length of the Large Intestines?
1.5 m
Involved in the mastication (chewing) of food
Teeth
incisors
biting
canines
tearing
molars
grinding/ mashing
A soft triangular gland that extends across the abdomen from the spleen to the duodenum
Pancreas
where do the pancreas release digestive enzymes and juices
duodenum (exocrine)
Produces insulin and glucagon
(endocrine)
Largest gland in the body which overlies the stomach
-Functions include synthesis of bile salts, detoxification, excretion, and energy metabolism
Liver
A small, pear-shaped thin-walled green sac that stores and concentrates the bile
Gallbladder
gallbladder releases ____ when it receives a signal that ___ is present in the duodenum
bile,
fat
voluntary process of placing the food into the mouth before it can be acted on
Ingestion
movement of food form one digestive organ to the next
◦example: peristalsis, and mass movement
Propulsion
A periodic squeezing or partitioning of the intestine at intervals along its length by its circular muscle
Segmentation
Opens in response to swallowing
Upper Esophageal Sphincter
- a.k.a. cardiac sphincter
* Prevents gastric reflux
Lower Esophageal Sphincter
- Found at the bottom of the stomach
* Prevents intestinal contents from backing up into the stomach
Pyloric Sphincter
- Found at the end of the small intestine
* Empties the contents of the small intestine
Ileocecal Valve
Prevents elimination until you choose to perform
Anus
Transport of digested end products from the lumen of the GI tract to the blood or lymph
Absorption
(nucleoplasmand cytosol)-a solution composed of small amounts of gases, nutrients and dissolved water
Intracellular Fluid
(fluid that bathes the cell’s exterior)-a solution composed of rich amounts of nutrients, hormones, neurotransmitters, salts and waste products
Interstitial fluid
Substances are transported across the membrane without any energy input from the cell
PASSIVE TRANSPORT PROCESSES
Particles move from areas where they are most concentrated to regions where they are less concentrated to become evenly distributed
example: osmosis of water
Diffusion
Unassisted diffusion of solutes through the plasma membrane
◦small ions
◦small molecules of lipids
◦water
Simple Diffusion
A protein carrier is needed to allow the substances to move down their concentration gradient
◦water soluble vitamins
◦fructose
Facilitated Diffusion
The cells provides the metabolic energy (ATP) that drives the transport process
have to move uphill (against the concentration gradient) large molecules
non-fat soluble
glucose and amino acid
ACTIVE TRANSPORT PROCESSES
Some large molecules are
moved into the cell via engulfment by
the cell membrane
Pinocytosis.
soft, rounded chewed food
BOLUS
thick fluid mass, partially digested
CHYME
body’s solid waste matter
FECES
a coordinated activity of the tongue, soft palate, pharynx and esophagus
Deglutition or swallowing
Presence of food & pH releases
GASTRIN
It takes ___ hours for the stomach to move its contents to the small intestine
4 hours
Pylorus holds ___ mL of chyme and squirts _. __ mL of into the small intestine at a time. This is to allow for the intestines to process the contents
30 mL
3 mL
stimulates liver & pancreas
Secretin
stimulates gallbladder & pancreas
CCK (cholecystokinin)
inhibits stomach activity
GIP (gastric inhibitory peptide)
Water and end products of digestion are absorbed along the length of the ____ ____
small intestines
contain undigested food residues, mucus, bacteria and water
FECES-
Large intestines is limited to the absorption of vitamins, some ions & remaining water
True or False.
True
Entire network of chemical processes involved in maintaining life; encompasses all of the sequences of chemical reactions that occur in the body
METABOLISM
Used to indicate chemical changes which take place in the cells and tissues which are necessary for the fulfillment of vital functions of a living organisms
METABOLISM
building compounds: uses energy
Anabolic
breaking down compounds (releases energy)
Catabolic
Accomplished by the kidney, the colon, the skin and the lungs
EXCRETION
The elimination of indigestible substances from the body via the anus in the form of feces
Defecation
foods that contain live/active cultures of specific strains of bacteria
Probiotics
Capacity to do work
Measured in units known as calories (amount of energy required to raise the temperature of 1 mL of water at 15 OC by 1 OC)
Energy
kcal= calories?
1kcal= 4.184 kJ~ 4.2 kJ
Body building nutrients
Water Proteins Fats Carbohydrates Minerals
Nutrients that Regulate body processes
Carbohydrates Fats Proteins Vitamins Minerals Water
Organic (carbon-containing) nutrients
Carbohydrates
Proteins
Fats(Lipids)
Vitamins
Inorganic nutrients
Minerals
Water
Nutrients a person must obtain from food because the body cannot make them for itself in sufficient quantity to meet physiological needs
“indispensable nutrients”
ESSENTIAL NUTRIENTS
can be synthesized endogenously by the body
NON-ESSENTIAL NUTRIENTS
present in relatively high amounts in the body: 0.005% of body weight or above
MACRONUTRIENT
The Macronutrients
Carbohydrates Fats Proteins Water Major Minerals (> 5 grams): calcium, phosphorus, potassium, sulfur, sodium, chloride, magnesium
present in the body in amounts less than <0.005% of body weight
MICRONUTRIENT
Saccharides, Greek word for sugar
Abundant in nature (plants)
Carbohydrates
CHO chemical formula
C6H12O6
Digestible CHO
Sugars, starches, dextrin, glycogen
Partially digestible CHO
Galactogen, mannosans, inulinand pentosans
Indigestible CHO
Celluloseand hemicellulose
Also called roughage (indigestible)
Dietary Fiber
Most common Dietary Fiber
Cellulose/cell wall
Others: hemicellulose, lignin, pectin, mucilages and gums
Chief source of energy
Cheap and main energy food
Protein sparer
Regulator of fat metabolism
CHO
CHO contains ___ – ___ mg glucose/ ml of blood
70 –100 mg glucose/ ml of blood
indicates relative increase in blood glucose levels after ingestion of CHO compare with a standard
Glycemic Index
Brain and nerve tissues can only utilize _____
glucose
provide immediate source of energy
Glycogen
In cerebrosides, components of the brain and nerve tissues
Galactoseand glucose
Infant feeding;stays longer in the intestines growth of bacteria absorption of Ca, synthesis of B-vitamins
Lactose
Detoxification and excretion
Glucuronicacid
(monosaccharide attached to non-CHO residue)drug therapy
Ex. Digitalis for heart disorder
Glycosides
Inulinclearancetest for kidney function
Inulin
Constituentsof nucleic acids (RNA and DNA)
Ribose and deoxyribose
what happens to excess CHO
stored as fat (lipogenesis)
breakdown of glycogen
Glycogenolysis
from products of intermediary metabolism of lactic acid, pyruvate and from non-CHO sources (non-essential amino acid and fat)
Gluconeogenesis
SIGNS of Protein-Energy Malnutrition (PEM)
- Decreased blood sugar
- Loss of weight
- Growth retardation
Fat and Protein intake is normal but CHO is not sufficient can lead to:
ketosis and acidosis
Rice enrichment laws:
addition of B1, B2and Fe to milled rice
◦2 cups: 1.6 mg B1, 13 mg B2, 10 mg Fe
RA 832:
Rice enrichment laws: regulates milling of rice (10% to brown rice)
PD 1211
Rice enrichment laws: fortification of rice with iron
Food Fortification Law (RA 8976)
Excessive intake is related to increase incidence of this microorganism
Streptococcus mutans
Sugar can contribute, but does not itself cause obesity.
TRUE or FALSE
True
Contributes to sweetness without added calories
Alternative Sweeteners
what is the six types of Sugars (4 kcal/g)
◦Lactose ◦Maltose ◦Glucose ◦Sucrose ◦Invert Sugar ◦Fructose
three types of Sugar alcohols (1.5 –3 kcals/g)
◦Sorbitol
◦Mannitol
◦Xylitol
- 180-200x sweeter than sucrose
- excessive intake is linked to bladder cancer in lab animals
- No longer considered having cancer causing potential
- Not a potential risk in humans
Saccharin
-Composed of phenylalanine, aspartic acid, and methanol
-180-200x sweeter than sucrose
-Not heat stable
-people with PKU
Complaints of sensitivity to aspartame
◦headaches, dizziness, seizures, nausea, etc.
Aspartame
~7000 –13000 times sweeter than sucrose
Structure is similar to aspartame (but not a risk for PKU)
Heat stable
Safe for use
Neotame
K for potassium
200x sweeter than sucrose
Not digested by the body
Heat stable
Acesulfame-K
600 x sweeter than sucrose
Substitute 3 chlorines for 3 hydroxyl groups on a sucrose
Heat stable
Excreted in feces (small amount in urine)
Sucralose
Isomer of fructose Approximately same sweetness as sucrose Poorly absorbed –low energy contribution No risk of dental caries Prebioticeffect
Tagatose
Liquid at room temperature
oil
solid at room temperature
fat
Storage of fat in the body
adipose tissue
Simple Lipids
Trigylcerides and fatty acids
Compound Lipids
Phospholipids
Sources of Phospholipids
eggs, soy beans, liver, wheat germs, peanuts
Cell membranes, emulsifiers
Derived Lipids
Sterols
Multiple-ring structure
Ex: bile, vitamin, sex hormones
Sterols
Only animal-derived foods contain cholesterol.
TRUE or FALSE
True
Lecithin is a major constituent of cell membranes and cell health is dependent on membrane integrity
Question: It is essential to supplement foods with lecithin. True or false
FALSE!
Lecithin is a NON-ESSENTIAL nutrient
Liver synthesizes lecithin that a person needs
Digestive tract: lecithinasehydrolyzes dietary lecithin only small amount reaches the cells intact
Excess will result to GI distress, sweating, salivation, loss of appetite
all carbons are saturated (no double bonds)
•All electrons in outermost valence of C are paired
Saturated Fatty Acid
Food sources of Saturated Fatty Acid
coconut oil, chocolate, butter, animal fat
Contains 1 double bond
Monounsaturated FA (MUFA)
Food sources of MUFA
Oleic acid in olive oil, avocado, almonds
Contains >2 double bond
Polyunsaturated FA (PUFA)
Food sources of PUFA
Linoleic acid in corn oil, soy bean oil, fish oils
Oxidation of Unsaturated Lipids will result to
rancid odor & taste
Oxidation of Unsaturated Lipids minimized by:
HYDROGENATION
◦adding H to increase saturation
◦reduces susceptibility to oxidation renders the fatty acids more stable from rancidity
Processed foods cause an increase in LDL cholesterol and decrease in HDL cholesterol which increases the risk of heart disease.
True or False
True
what FA chain consist of 6 C or less
Short-chain
examples of Short-chain FA
Butyric acid, CaproicAcid
what FA chain consist of 6–12 C
Medium-chain
examples of Medium-chain FA
Stearicacid, Lauric
what FA chain consist of >12 C
Long chain
examples of Long chain FA
Palmitic, EPA, DHA
- largest, least dense, carry greatest number of TGs
- carry TGs from intestine to the rest of the body
Chylomicrons
-provide cholesterol and few TGs to cells in muscles, the heart,fat stores, mammary glands, etc.
Low Density Lipoprotein (LDL)
- LPs synthesized in the liver for deliveryto other body cells of TGs
- VLDL “drops off” TGs at differ-grows smaller in size as lipids are carried to other cellsent sites
Very Light Density Lipoproteins
VLDL
-protein remnants of LPs get dismantled in liver for recycling
Chylomicrons
-LPs with low pro to lipid ratio
Low Density Lipoprotein (LDL)
-After losing TGs, VLDL picks up cholesterol circulating in the bloodstream
VLDL -> LDL
Very Light Density Lipoproteins
VLDL
- LPswith high pro to lipid ratio
- synthesized in the liver
- carry cholesterol and PLs from cells back to the liver for breakdown or disposal
High Density Lipoprotein (HDL)
Arrange in descending order according to density: ◦LDL ◦Chylomicrons ◦HDL ◦VLDL
Descending order according to density.
- HDL: half protein, accounting for high density
- LDL: half cholesterol, accounting for implication in heart disease
- VLDL: half TG, accounting for low density
- Chylomicrons: so little protein and so much TG that they are the lowest in density
The body can produce its own cholesterol needed.
TRUE or FALSE
True
The body can produce its own cholesterol needed
◦To make:
◦To make: vitamin D in the skin
◦To make bile and hormones
we don’t eat more than 300 mg of cholesterol per day
TRUE or FALSE
True
what cholesterol helps protect against heart disease
Increased values are better
Good Cholesterol (HDL)
what cholesterol
- Increases risk of heart disease
- Reduced values are better
- Diets high in saturated fat and trans fatty acids raise LDL levels
Bad Cholesterol (LDL/VLDL)
Normal Blood Values of HDL
HDL= 40 mg/dL or higher
Normal Blood Values of LDL
LDL= <130 mg/dL
There is No GOOD or BAD cholesterol in food
TRUE or FALSE
True
Only animal food contain cholesterol.
The liver produces the good and bad cholesterol from the food that we eat
TRUE or FALSE
True
Butter, Lard, Whole milk, cream, cheese, Meat and meat products . Poultry skin. Egg yolk are mainly ___ fat.
animal fat
Palm oil, Palm kernel oil are mainly from ____ .
plant
Physical activity helps to increase the level of good cholesterol (HDL) in your blood
TRUE or FALSE
True
Most TFAs found in:
Commercially prepared baked foods, Margarines, Snack foods (chips, biscuits, cookies)
Most TFAs are naturally found in:
Meat and dairy products
TFAs are also associated with _____, making them especially harmful to health
inflammation
obesity is more directly linked to ____
total fat
cancer is more directly linked to ____
unsaturated fat
CVD
cardiovascular disease is more directly linked to ____
saturated
Greek word PROTEIOS, means
“to hold first place or of prime importance”
WHAT ARE PROTEINS
Complex molecules –building blocks of life made of chains of amino acids
CHON structure that yield only amino acid on hydrolysis
Simple
CHON structure that has prosthetic group attached to a carbon
Conjugated
CHON structure that has substances produced by partial hydrolysis
Derived
AA that contains all essential amino acids
Complete or High Biologic Value: (all animal food except gelatin)
AA that can maintain life but don’t support
growth
Partially complete
AA that cannot support life nor growth
Incomplete
addition of amino acid in desirable levels so that food contains greater than what originally exists (lys to bread)
Fortification
restore what was lost in processing (lys to Cerelac)
Enrichment
addition of protein to regular diet to improve protein quality
Supplementation
combination of food proteins such that one lacking may be supplied by another
Complementation
Plant combination which provides adequate amounts of essential amino acids to adequately support human protein synthesis
PROTEIN COMPLEMENTARITY
Precursor ofniacin andserotonin
Tryptophan
Detoxifies harmful substances
Glycine
Donates nitrogen to be used for formation of alaninein the glucose-alanine-cycle
Leucine, Isoleucine, Valine
an intestinal brush border enzyme that activates pancreatic proteases stimulated by trypsinogencontained in pancreatic juice
Enterokinase
Secretes proteasesas proenzymes
Pancreas
Index of the amount of PRO utilized by the body
Nitrogen balance
correct proportions, present at right site and time (egg protein as model)
Amino acid composition
causes loss of protein
Immobility
Newborns CHON requirement
2.5g
Children 0.5–1 yrs CHON requirement
2.0g
Children 7–10 yrs CHON requirement
1.5g
Healthy adults CHON requirement
0.8g -1.2g
State of deficit in body protein or in one or more of the essential amino acids
Protein Deficiency
Results from inadequate dietary protein, energy or both
Common: 1-3 years of age; cause of mortality, morbidity and impairment of physical and mental growth
Prolonged:
Kwashiorkor
Marasmus
Protein Energy Malnutrition (PEM)
“the disease (Africa: an evil spirit) that occurs when the next baby is born”
Kwashiorkor
Characteristics: wasting, emaciation, no edema, quiet and apathetic
Marasmus
Inadequate protein intake with a fair or normal intake of energy
Kwashiorkor
Results from deficiency of both protein and energy (predominantly energy deficiency)
Marasmus
depigmentation of hair & skin, edema in the limbs and flabby moon-like face, irritable , moaning and apathetic
Kwashiorkor
Capacity to do work
Energy
Generation of heat
Index of how much energy is spending
Thermogenesis
Exercise-induced thermogenesis:
physical activity
Basal thermogenesis:
basal metabolism
Diet-induced thermogenesis:
thermiceffect of food (TEF) or specific dynamic action of food (SDA)
Adaptive thermogenesis:
energy of adaptation (very variable)
The minimum energy expended to keep a resting, awake body alive
~60-75% of the total energy needs
Needed for maintaining a heartbeat, respiration, body temperature
Varies between individuals
Basal Metabolism
Energy used to digest, absorb food nutrients
Thermic Effect of Food (TEF)
Nonvoluntary physical activity
◦Increases in the sympathetic nervous system activity
◦Triggered by overeating or cold environment
Adaptive thermogenesis
Energy lost as heat
Brown adipose tissue
◦Measures heat output from the body using an insulated chamber
◦Expensive and complex
Direct calorimetry
◦Measures the amount of oxygen a person uses
◦A relationship exists between the body’s use of energy and oxygen
◦(1 L O2= 4.85 kcal)
Indirect calorimetry
◦Consume water containing 2H and 18O
◦Measure isotopes in body fluids
Stable isotopes (Doubly labeled water)
◦Estimates resting energy needs
◦Considers height, weight, age, and gender
Harris-Benedict equation
State in which energy intake, in the form of food and/or alcohol, matches the energy expended, primarily through basal metabolism and physical activity
Energy Balance
◦Energy intake >energy expended
◦Results in weight gain
Positive energy balance
◦Energy intake
Negative energy balance
What is obesity?
An excess of body fat
STORAGE FAT
ADIPOSE TISSUE
lower body fat distribution
gynoid: pear shape
Upper-body fat distribution
android: apple shape
◦Use calipers to measure subcutaneous fat
◦Mathematical formula estimates body composition
Skinfold thickness
◦Low-energy current to the body that measures the resistance of electrical flow
Bioelectrical impedance analysis
Desirable amount of body fat for women
21 –35% for women
Desirable amount of body fat for men
8 –24% for men
◦Estimate body volume by measuring amount of air displaced when body is in a chamber
◦With body weight, can estimate body density
Air displacement (Bod Pod)
◦An X-ray body scan that allows for the determination of body fat, fat-free soft tissue, and bone
◦Also used for study of osteoporosis
Dual-energy X-ray absorptiometry
