Transcript of Nutrition in Humans. NutrientsPart I Nutrients are the usable portions of foods What are nutrients...
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- Nutrition in Humans
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- NutrientsPart I Nutrients are the usable portions of foods What
are nutrients used for? 1. Energy Sources 2. Building or Repair of
cell structure 3. Regulate metabolic processes
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- 6 Main Groups 1. Carbohydrates (bread, pasta, potatoes, candy)
2. Proteins (beef, fish, milk, peas, nuts) 3. Fats & Oils
(butter, bacon, vegetable oil) 4. Water (most foods contain water)
5. Minerals (calcium, iron, sodium, chlorine) 6. Vitamins ( A, B 1,
B 2, Niacin, B 12, C, D, K)
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- Which are organic and which are not? Organic 1. Carbohydrates
2. Proteins 3. Fats N Oils 4. Vitamins Inorganic 1. Water 2.
Minerals
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- What about What we cant digest Roughage: indigestible food
Examples: fibrous matter (cell wall) in fruits, vegetables, and
whole grains Benefit: provides bulk to be worked on by muscles,
keeps things moving forward
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- Carbohydrates Subunit: Saccharides 1. Monosaccharides:1 (simple
sugars, glucose) 2. Disaccharides: 2 (sucrose and maltose) 3.
Polysaccharides: 3 or more (Starch in plants and Glycogen in
animals)
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- Regents Question Most of the starch stored in the cells of a
potato is composed of molecules that originally entered these cells
as (1) enzymes (2) simple sugars (3) amino acids (4) minerals
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- Why can glucose diffuse through the cell membrane and Starch
can not? Glucose is a monosaccharide and much smaller than the
polysaccharide of Starch
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- Proteins Subunit: Amino Acids (NH 2 = amino group COOH =
carboxyl acid)
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- Regents Question Two proteins in the same cell perform
different functions. This is because the two proteins are composed
of (1) chains folded the same way and the same sequence of simple
sugars (2) chains folded the same way and the same sequence of
amino acids (3) chains folded differently and a different sequence
of simple sugars (4) chains folded differently and a different
sequence of amino acids
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- Regents Question Which statement concerning proteins is not
correct? (1) Proteins are long, usually folded, chains. (2) The
shape of a protein molecule determines its function. (3) Proteins
can be broken down and used for energy. (4) Proteins are bonded
together, resulting in simple sugars.
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- Proteins The Human body need 20 different types of Amino Acids
12 of the 20 humans can synthesize (produce) 8 of the 20 humans can
not, these 8 are called Essential amino acids (Isoleucine, Leucine,
Lysine, Methionine, L- Phenylalanine, Threonine, Tryptophan and
Valine)Isoleucine, Leucine,LysineValine
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- If proteins come mostly from meat, how do vegetarians get the 8
essential? There are 2 types of proteins 1. Complete Protein:
contains all essential amino acids 2. Incomplete Protein: missing
one or more essential amino acids So to answer the question: a
vegetarian can eat a combination of incomplete proteins to provide
all essential amino acids (ex. Rice and Beans)
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- What happens if you are missing one of the essential 8? You
would get a protein-deficiency disease. Example: Populations in
Africa diet consist of cornmeal (incomplete protein) lacks
Tryptophan. These children have a disease called Kwashiorkor (tired
and abnormal growth)
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- Fats (Lipids) Synthesized in body from Fatty acids and Glycerol
Represents stored energy Together with proteins synthesize the cell
membrane
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- Fats (Lipids)
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- Bad Fat Saturated Fat: Usually solid at room temperature, No
Double Bonds, lead to cholesterol deposits in blood vessels
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- Good Fat Unsaturated Fat: consists of oils (liquid at room
temperature), one or more Double Bonds
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- Minerals Important inorganic material (helps in structure of
cells and tissues) Calcium (Ca): strong teeth and bones, milk &
eggs Iron (Fe): helps in formation of red blood cells (red
pigment), liver, meats & vegetables Sodium (Na): needed for
proper cell function, table salt
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- Vitamins Like minerals, perform many functions Especially
important growth of children In adults repair and maintain healthy
body functions Unable to be synthesized by humans
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- Vitamins A: healthy eyes & skin, green and yellow
vegetables B1: growth and appetite, meats, seafood, milk B12:
production of red blood cells, liver & green vegetables C:
healthy teeth, gums, and blood vessel repair, fruits D: growth and
maintenance of bones, produced in skin exposed to sunlight &
fortified milk K: blood clotting, liver function, synthesized by
bacteria in body
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- Water Excellent solvent (dissolves many compounds) Main
component of fluid transport (blood) Many chemical reactions take
place Lubricant for joints and digestive system Cools body by sweat
evaporation Lost by breathing, urination, and elimination
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- What is a calorie? The amount of heat needed to raise 1mL of
water by 1 C 0 Unit of measurement for energy value in food
Calorimeter: tool used to measure calories in foods
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- Food Additives Saccharin: artificial sweetener Nitrites:
protect food from bacterial decay and provide red color, found in
bacon hotdogs, and deli meats Monosodium glutamate (MSG): flavor
enhancer
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- The Digestive System PartII
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- What is the Digestive System? The alimentary canal (coiled tube
which ingested materials move in one direction) and digestive
glands make up the digestive system Hydrolysis
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- What are the functions of the Digestive System? There are 3
main functions of the Digestive system 1. Ingest foods (eat) 2.
Breakdown foods so nutrients can be absorbed 3. Eliminate
(egestion) what can not be digested
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- Regents Question Which order of metabolic processes converts
nutrients consumed by an organism into cell parts? (1) digestion
absorption circulation diffusion synthesis (2) absorption
circulation digestion diffusion synthesis (3) digestion synthesis
diffusion circulation absorption (4) synthesis absorption digestion
diffusion circulation
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- When does digestion start? As soon as we place food in our
mouth. Mechanical and Chemical digestion occurs Mechanical
digestion = Chewing Chemical digestion= Saliva
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- Digestion in the Mouth Mucus Glands: lubricant for food in the
form of mucus (allows food to travel smoothly) Saliva Glands:
contains amylase (enzyme) which breakdown starch into maltose
Polysaccharide (starch) to a Disaccharide (maltose)
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- From your mouth to your Esophagus Swallowing: coordinated
reflex action that moves food to the esophagus During swallowing
the trachea (windpipe) moves upward against the epiglottis
(flap)
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- Esophagus Food is moved from the mouth to the stomach The
movement is called Peristalsis: muscle contractions and relaxations
(moves in waves, like pushing a tube of toothpaste)
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- Stomach Muscular organ that churns food and initiates protein
digestion (balloon like, expands when full and shrinks when
empty
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- Stomach (Gastric Juices) Gastric Glands: located on the inner
lining of the stomach Contains peposinogen and hydrochloric acid
HCl (keeps pH at 2 and kills off bacteria) Acidic environment
favorable for pepsin (enzyme) to breakdown proteins Rennin: an
enzyme that changes liquid proteins into a solid state (curdles
milk proteins)
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- Stomach (final product) The process takes about 2 to 24 hours
(depending of the foods present) Chyme: mixture of saliva, gastric
juices, and water
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- Which organs of the digestive system never in contact with
food? 1. Liver: secretes bile (aids in digestion of fats)
emulsification (makes small globules of fat from large ones) 2.
Gallbladder: bile is stored here and transport to small intestine
via bile duct 3. Pancreas: pancreatic juices (enzymes) Proteases=
protein digestion Amylase= carbohydrate digestion Lipase= fat
digestion
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- Liver, Gallbladder, & Pancreas
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- Small Intestine 1. Longest part of digestive tract (7m) 2.
Called small because of diameter (6.5 cm) 3. Most digestion and
absorption occurs here
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- Absorption in Small Intestine Villi: tiny projectiles on the
inner surface of small intestine There are enough villi in your
small intestine to cover a tennis court (large surface area)
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- How do the nutrients leave the Small intestine? 1. Diffusion 2.
Villi only 1 cell thick 3. Amino acids and simple sugars enter
capillaries 4. Fats enter lacteal (lymph vessel)
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- Small Intestine is an excellent example of adaptation 1.
Muscles contract to mix liquids and bring them to villi 2. Great
length and folds provide large surface area for absorption 3. Villi
provides large surface area (ten times greater than skin) 4. Thin
membrane allows for easy diffusion of nutrients
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- Large Intestine No digestion occurs here Water absorption
Contains bacteria which produce vitamins Eating yogurts help
replenish lost bacteria
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- Time of Digestion Mouth: 5-10 sec Esophagus: 10 sec Stomach: 2
to 24 hours Small Intestine: 3 to 4 hours Large Intestine: 18 hours
to 2 Days
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- Elimination (egestion) Feces or waste is stored in the rectum
(lower part of large intestine) Feces leaves our body through the
anus
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- Problems in Digestion What do you call a hole in your stomach?
Ulcer: occurs when HCl (hydrochloric acid) and pepsin are in direct
contact with the stomach lining. (little to no Mucus present)
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- Why cant I Poop? Constipation: occurs in the Large intestine,
happens when too much water is absorbed and the feces hardens What
is the opposite of constipation? Diarrhea: Not enough water in
absorbed in the Large intestine and the feces remains soft and
watery (may be a symptom of infection or stress)
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- Appendicitis Inflammation of the appendix (located where the
small intestine meets the large intestine) Symptoms: abdominal
pain, nausea, and fever Surgery usually needed to remove before
rupture
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- Gallstones Harden deposits that form in the gallbladder
(deposits may block the bile duct, causing pain)