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Unit 7
NUTRITION
Obtaining food and breaking it down into a
usable form for cells.
A.) Introduction
1. There are two basic types of NUTRITION:
AUTOTROPHIC
NUTRITION
Organisms produce their own food
ex. photosynthesis
HETEROTROPHIC
NUTRITION
Organisms obtain their food from the environment
2. The process of breaking food down is called
DIGESTION
3. There are two basic types of DIGESTION:
MECHANICAL DIGESTION
Food is broken down into smaller pieces physically.
(No Enzymes!!)
CHEMICAL DIGESTION
Food is broken down into end products or building
blocks. (Enzymes Required!!)
MECHANICAL DIGESTION
CHEMICAL DIGESTION
Carbohydrates (Starch)
Proteins
Fats
Nucleic Acids
Simple Sugars
Amino Acids
Glycerol and Fatty Acids
Nucleotides
4. Some organisms digest the food within their
cells.
This is called Intracellular Digestion
5. Some organisms digest the food outside of
their cells.
This is called Extracellular Digestion
Which do humans have?
B.) Nutrition in Protists
1. Amoeba - (Heterotrophic)
Ingestion - food is engulfed with pseudopods
Digestion - intracellular within a food vacuole
Egestion - indigestible material exits out through the
plasma membrane
2. Paramecium - (Heterotrophic)
Ingestion - food enters in through the oral
groove with the help of cilia
Digestion - intracellular within a food vacuole
Egestion - indigestible material exits out
through the anal pore
3. Euglena - (Heterotrophic & Autotrophic)
Ingestion - food is absorbed in through the
plasma membrane
Digestion - intracellular within a food vacuole
Egestion - indigestible material exits out
through the plasma membrane
C.) Human Digestive System
1. Basic Structure (see diagrams)
2. How is Food Digested? (see handout)
3. How are Nutrients Absorbed? (see handout)
http://www.youtube.com/watch?v=P1sDOJM65
Bc
http://kitses.com/animation/swfs/digestion
.swf
4. Malfunctions of the Human Digestive System
Ulcers - An ulcer is a sore in the lining of the
stomach OR small intestine.
Caused by an overproduction of
gastric juice.
Constipation - Feces is very dry and hard
making egestion very difficult.
Lg. Intestine reabsorbs too much
water. Usually caused by
dehydration
Diarrhea - Feces is very wet and loose causing
frequent urges of egestion.
Lg. intestine does not absorb water
from the wastes. There are many
causes. Common cause is an
intestinal pathogen
Gallstones – Tiny cholesterol deposits that
accumulate in the gall bladder.
Stones may get lodged in the bile
duct causing intense pain.
Celiac Disease - a condition that damages the lining of
the small intestine and prevents it from absorbing parts
of food that are important for staying healthy. The
damage is due to a reaction to eating gluten, which is
found in wheat, barley, rye, and possibly oats.
A kidney stone, is a solid, crystal aggregation formed
in the kidneys from dietary minerals in the urine.
Dehydration, high dietary intake of animal protein,
sodium, refined sugars, fructose, and high fructose
corn syrup increase the risk of kidney stone formation.
Gout is a type of arthritis. It occurs when uric acid
builds up in blood and causes inflammation in the
joints.
Gout is caused by having higher-than-normal levels of
uric acid in your body. This may occur if:
Your body makes too much uric acid
Your body has a hard time getting rid of uric acid
D.) Human Endocrine System
1. Regulates internal control of the body.
2. This system is made up of a series of special
glands called ENDOCRINE GLANDS
3. Endocrine Glands release hormones directly
into the bloodstream.
4. Human Endocrine Glands
(see handouts)
5. Hormones are chemical messengers
Most hormones are
PROTEIN
S
Some hormones are
STEROIDS (lipids)
6. Hormones in the Human Body (see handout)
E.) Hormones, Receptors, and
Target Cells
1. Because hormones circulate in the blood,
they come in contact with most cells of the
body. BUT, specific hormones only affect
specific cells called TARGET
CELLS
2. A TARGET CELL responds to a hormone
because it bears RECEPTORS for that hormone
3. 1 Messenger Hormone Mechanisms
vs.
2 Messenger Hormone Mechanisms
(see handout)
4. Negative Feedback Loops
-systems that regulate the levels of certain
chemicals in the body.
(see handout)
F.) Malfunctions of the
Endocrine System
1. Diabetes - Individuals maintain HIGH levels of
glucose in the blood. High blood glucose levels
disrupt homeostasis.
Type 1 = Individual does not produce adequate
amounts of INSULIN
Type 2 = Individual has defect with their insulin
RECEPTORS on the Liver
2. Goiter = Enlarged Thyroid Gland due to iodine
deficiency