Upload
others
View
5
Download
0
Embed Size (px)
Citation preview
Nutrition
� the activities by which organisms obtain and process material needed for
energy, growth, repair, and to maintain
homeostasis� humans are ____________ — they have � humans are ____________ — they have
to get their food from somewhere, they
cannot make it on their own.� humans need food; which can be described as either _____________ or
_____________
Why do humans need food?
� Animals make energyavailable using:
� food (glucose)
� oxygen
� Animals build bodies
food
� Animals build bodiesusing:
� food for raw materials� amino acids, sugars, fats, nucleotides
�ATP energy for synthesis
O2
ATP
mitochondria
How do some animals get their food?
filter feeding living in your food
fluid feeding bulk feeding
NUTRIENTS ROUGHAGE
� ____________*
� ____________*
� ____________*
� ____________¤
� ____________¤
� ____________¤
complex carbos that
cannot be broken down but
is necessary for the
digestive system to work;
found in _______________
_______________________� ____________¤ _______________________
*carbos, lipids, and proteins MUST be _______
first; vitamins minerals and water can be
absorbed without digestion
¤ vitamins, minerals, and water are not used for
energy or building structures, but are needed!
Different diets; different lives� All animals eat other organisms
�Herbivores
� eat mainly plants
� gorillas, cows,
rabbits, snails
�Carnivores
� eat other animals
� sharks, hawks, spiders, snakes
�Omnivores
� eat animals & plants
� cockroaches, bears, raccoons, humans
� humans evolved as hunters, scavengers & gatherers
1. Ingestion: ____________________________2. Digestion: ____________________________ mechanically (physically) and chemically (enzymatic hydrolysis)
3. Absorption: __________________________ _____________________________________
The human digestive system is responsible for:
_____________________________________
4. Elimination: __________________________ _____________________________________
the human digestive system (also called
alimentary canal) is a one-way
gastrointestinal tract with two openings
Other gastrointestinal tracts…
Everybody’s got one!
Human digestive
system
food is moved in the correct direction by slow
muscle contractions called _______________
Ingestion
1) oral cavity (mouth)� __________ of food
occurs here� contains teeth, tongue and openings
of the salivary glands
A.A. teeth� used to break down food physically
( ) to increase surface area for digestive enzymes ( )
IngestionB. tongue
� moves food around mouth so that the teeth work more effectively
� helps mix food with saliva, and moves food to the back of the mouth for
C. salivary glands� secretes ______ into digestive system
which contains the hydrolytic enzyme _________ which digests starch
food to the back of the mouth for swallowing
� ________________________________ ___________________________________
Swallowing (& not choking)
2) esophagus� when you swallow, food goes into this
tube then to the stomach
� mucus is secreted here to lubricate
the food to ‘slide down’ easier
� __________________________
__________________________
Swallowing (& not choking)
A. epiglottis� when you swallow, this ___________
________________________________
(trachea) so that food will not go into
the lungs
� this momentarily stops
breathing!
3) stomach� a thick-walled,
muscular sac
(organ) whose main
job is to liquify the
food ingested
� the lining of the
stomach contains stomach contains
gastric glands
which secrete
gastric juices which
contain:a) gastric proteaseb) hydrochloric acidc) mucusd) water
3) stomach� gastric protease—an enzyme which begins
the digestion of ______________
� the hydrochloric acid (HCl) lowers the pH of the stomach… not to break down food, but to provide the ____________________ ____________________________________!
stomach
pepsin (protease)
pH
reaction
rate
7
3) stomach� the _________
protects the stomach walls from being eaten away away
� the water is used for chemical digestion ( __________ )
4) small intestine� partially digested food
then enters the small intestine
� is a long tube (over 20 feet!) where ______
____________________________________
Digestion/Absorption
____________________________________
� intestinal glands line the intestinal walls
and secrete lipase, maltase, and intestinal
protease to __________________________
� food is digested along with the help of
accessory organs
Accessory Digestive Organs A. liver
� produces ______
� ___________________; however it does
break down fats—big globs to little
‘globblets’—called ____________________
bile contains
colors from old red
blood cells
collected in liver =
iron in RBC rusts &
makes feces brown
Accessory Digestive Organs B. gall bladder
� ____________________________________C. pancreas
� secretes enzymes into the small intestine
such as intestinal amylase, intestinal
protease, and lipase
the pancreas
also produces
insulin and
glucagon to
regulate blood
sugar levels
protease, and lipase
5) large intestine� takes the undigested food
and ___________________
______________________
� solidifies the liquid wastes
into solid feces (includes
Absorption/Egestion
into solid feces (includes
undigested and
indigestible material—
roughage, bacteria, bile,
mucus, worn out cells)
� ______________________
______________________
You’ve got company!
� Living in the large intestine is a community of helpful bacteria
� Escherichia coli (E. coli)
� produce vitamins
� vitamin K; B vitamins� vitamin K; B vitamins
� generate gases
� by-product of bacterial metabolism
�methane, hydrogen sulfide
A. appendix� has no known function in modern humans,
however, if inflammed, can be life
threatening!
Vestigial organ B. rectum� where solid wastes are temporarily stored
C. anus� opening in the alimentary canal where
feces are removed (egested)
Different diets; different bodies
� Adaptations of herbivore vs. carnivore
� teeth
� length of digestive system
Teeth
� Carnivore
� sharp ripping teeth
� “canines”
� Herbivore
wide grinding �wide grinding teeth
�molars
� Omnivore
� both kinds of teeth
Length of digestive system
� Carnivores
� short digestive
systems
� protein easier to
digest than cellulose
� Herbivores & omnivores� Herbivores & omnivores
� long digestive
systems
� harder to digest
cellulose (cell walls)
� bacteria in intestines
help
REVIEW OF CHEMICAL DIGESTION
_________
+
H2O
� ____________________________________________________________________
REVIEW OF CHEMICAL DIGESTION� in organisms, this process is regulated by hydrolytic enzymes
a protease
� remember, the first part of the enzyme’s name tells you what the enzyme works
on ( _____________ )!
a protease
Digesting important polymers
glucose – glucose – glucose – glucose – glucose
Carbohydrates = digested to ______________
Proteins = digested to _______________Proteins = digested to _______________
Lipids = digested to _____________________
aminoacid
aminoacid–
aminoacid–
aminoacid–
aminoacid–
aminoacid–
ABSORPTION OF DIGESTED MATERIALS� ____________________________________________________________________________
� the intestinal wall is lined with millions of ______ which ___________________________
ABSORPTION OF DIGESTED MATERIALS� in each individual villi (shown below with their microvilli) there are capillaries (small blood vessels) and other small ducts (pipes) of the lymphatic system called lacteals
ABSORPTION OF DIGESTED MATERIALSI. CARBOHYDRATES:
� glucose (a _______________ ) is absorbed into the bloodstream by the capillaries
� it there can be sent to the liver to be stored temporarily as _________________ ____________________________________
when the body needs energy (more � when the body needs energy (more glucose) the glycogen can be broken back down and released into the bloodstream
ABSORPTION OF DIGESTED MATERIALS
II. PROTEINS:
� ____________________________________
____________________________________
� amino acids can be stored in the liver until
they are needed
� there are 20 different � there are 20 different
amino acids that
humans need to
make up proteins
� __________________
__________________
__________________
__________________
� Need to make sure you get enough protein
� 20 amino acids to make protein
� 12 amino acids humans can produce
� 8 we have to eat = “essential amino acids”
� Grains (like corn) have 6 (missing 2)
� Beans (like soybean & red beans)
Vegetarian Diets!
� Beans (like soybean & red beans)
have 6 (missing different 2)
� mix beans & grainsfor complete group of
amino acids
� rice & beans
� taco/tortilla & beans
� tofu & rice
� peanut butter & bread
ABSORPTION OF DIGESTED MATERIALS
III. LIPIDS:� the building blocks of lipids fatty acids
and glycerol are absorbed into the ______
and are passed along to the lymph (other
transport fluid—besides the blood)
� they _________________________ through � they _________________________ through
this other set of pipes
Saturated fats
� ________________________________(
butter, grease)
� lots of hydrogen atomsatoms
� too much in the diet can be linked
to ______________
________________
Unsaturated fats
� ____________________________
(oils)
� less hydrogen atoms than atoms than
saturated fats
� does not appear to be linked to
cardiovascular
disease
Saturated vs. unsaturatedsaturated unsaturated
1) Ulcers:� ____________________________________
� used to think ulcers were caused by stress
� now know ulcers caused by bacterial
infection of stomach
MALFUNCTIONS OF THE HUMAN
DIGESTIVE SYSTEM
infection of stomach� H. pylori
� now cure with antibiotics
2) Appendicitis: ( ___ = inflammation)� ____________________________________
� can be life threatening if it ruptures
3) Gallstones:� ________________________________________
________________________________________
� affects secretion of bile into small intestine
4) Constipation: � a condition in which the large intestine is
emptied with great difficulty due to:
5) Diarrhea: � a gastrointestinal disturbance which results
in:
� ____________________________________________
� ____________________________________________
� can result in severe dehydration!
� ____________________________________________
� ____________________________________________