The small intestine has lots of surface area. This allows the lumen to do....
1. Secret
2. Absorbs
Absorption starts in earnest in the _____
Duodenum
Some things are absorbed into the cells lining the GI by simple ______________
(moving across a wall)
diffusion and/or osmosis
Some things get taken into up by facillitated diffusion (means there are specific protein carriers)
Float into body
Some are taken up by active transport which ______
requires energy
Liver gets 1st call on all the blood and the heart gets the leftovers
Bloos leaving the liver then behaves itself and heas directly to the heart and does not pass "go"
Blood leaves the gut and goes directly to the ____
liver
____ is a good place for glycogen
Liver
Mechanism for dealing with food-rich blood
Hepatic Protal System
_____is produced by the liver and stored in the ______
It is good for digestion
Bile
Gall Bladder
Hepatic Portal Vein ________ liver
Common Bile Duct _________liver
Lets into the
Takes out of the
______ contains white blood cells and is where the fat gets absorbed
Lymph
Water get absorbed and reabsorbed in the ________
small intestine
Fats get taken to the _____system in the gut
Lymph
All chemical reaction that happen in the body and have energy required for them is called _____
Metabolism
Carbohydrate (glucose) concentrations in blood are very closely regulated, as carbs (again glucose really) are key/immediate/sometimes almost exclusive source of energy, especially for the brain.
(Carbs) Energy for metabolism quick source of energy
______ liberate sugar from glycogen so it can be broken down
Glycagen
______ is the horomone responsible for packing away energy
Insulin
Insulin takes blood into the cell
Glycogen takes blood out of the cell
______ is the key player in the process which can be liberated when blood concentrations fall
Glucagon
______ puts the sugar into the liver and muscle in the first place
Insulin
The four forms of human energy
1. Chemical
2. Electrical
3. Mechanical
4. Thermal
The ultimate source of energy here on earth is _____
sunlight
In photosynthesis, plants use solar energy to convert water and carbon dioxide to chemical energy also known as ______
Sugar
In our bodies food needed for energy is converted to _______
Glucose
_______ and _____ are biproducts of energy metabolism in our bodies.
They are also used as the material by plants
Water
Carbon Dioxide
Metabolism
Energy that has been transformed in one way or another in order to facilitate the bodies needs
Moving energy from one band to another band
Chemical bonds
The bonds that hold molecules together
______ bonds are strong bonds
Covalent
Energy
We can put it to work
We lose 90% of energy in bond transitions
This becomes heat that we give off daily to keep us warm
No mater what, source of energy will always give off ____
heat
Heat will always be given off
Enzymes
Speed up reactions
Are present in all proteins
Energy release rates must be controlled else
we will burn up
Energy reactions in cells are regulated by
Energy
Hormones
Temperature
There are two types of metabolic reactions
1. anabolic
2. catabolic
Anabolic
Builds things
Where the majority of food energy is spent
Synthesizes new and more complex substances
Catabolic
Tears things down
Breaks down more complex substances to simpler ones
Breaks down foods then hands it to the anabolic
Glycogen-----(Glucagon-breaks down)-----Glucose
Reserves
1. Glycogen
2. Adipose
3. Muscle
Calorie
The amount of heat required to raise 1 kg of water 1 degree Celcius
Calorimeter
Calorie counter
Measurment of food energy
Kilocalorie
Calorimetry
Approximate Compostion
Three reasons we need energy
Basal metabolic rate (BMR)
Thermic effect of food (TEF)
Physical activity
BMR
Basal metabolic rate
the energy needed just to keep us going without the extra conditioning
The measure of energy required to maintain the body at rest
TEF
Thermic effect of food
Energy used in the food process
The investment of energy that we put in food so we can change it into building sources
About 10% of energy in food is used to simply "use" the food
Takes more energy to break amino acids (proteins) than carbs -burn more calroies
may explain why high protein diets help people loss weight
BMR expenditure
60-70% of total energy
TEF expenditure
10% of total energy
Four body compartment
lean body mass
body fat
body water
mineral mass
Women require 12% body fat
Men require 3% body fat
Women require a body fat of about ____ for otimal reproductive potential
20%
BMI
Body mass index
Muscle is about ______ the density of fat
1.2 x
Muscle is more dense than fat
Desirable BMI in adults is
18.5 to 24.9
Problems associated with weight and obesity
1. metabolic problems
-Type 2 diabetes and hypertension
-elevated blood lipids
2. Degenerative problems
3. Neoplastic (Cancer) problems
4. Anatomic Problems
-Gastroesophageal reflux disease (GERD)
-Sleep apnea (stop breathing)
Anorexia nervosa
self-induced starvation
Refusaul to eat
Bulimia Nervosa: gorging-purging
Eating food then purging it again
Goal of underwight person renutrtion
1. Feed diet high in kcalories at least 50% above standards
2. Feed diet high in protein to rebuild tissues
3. high in carbs to get energy source back
4. moderate fat, dont exceed recommended limits
5. optimum in vitamins and minerals
Vitamins
Organic dietary substance what have no significant energy value
ADEK
absobed in fat (fat soluable)
Vitamins B complex and C
water soluable
easily transported
Vitamin A is a generic name for _____
retinoids-play a role in vision
Plants cant make retinoids, instead they make beta-carotene and body (By metabolism) makes it into vitamin A
Provitamin A
beta-carotene
_____ is made fromo cholesterol and is good at absorbing fat-soluable vitamins
Bile
______ is the place where we store the most vitamins
Liver
Bile salts bring Vitamin A in
Dietary fat must be present too
Liver contains 85% of vitamin A
Functions of Vitamin A
1. helps vision
2. helps to make epithelial tissues (skin)
---absence leads to keratinization
VA sources
Animals sources
and fortified foods
Vitamin D
is Sterol
is the final product of Cholcalciferol (vitamin D3)
absorbed in the small interstine along with fat
Functions of VD
Cell growth
Maintaince of bones
Lack of VD leads to _____
rickets
Vitamin E is also called ______
tocopherol
Its a group of compounds with similar phy activity
Acts as an antioxidant in destroying free radicals
Antioxidant
sucks up the free radicals and they neutralize them
Anemia
not enough red blood cells in body ergo not enough oxygen carried aroud the body
Disrupts the making of mylin aroud the nerves
Anemia
Sources of VE
found in vegetables oils
VE is the only fat-solable vitamin with no known toxicity at very high doses
Vitamin K
"k" comes from cwagulation
Good for blood clotting
Good for bone metaolbism and health and maintainence
little is stored in the liver, we are rapidly getting rid of it in excretion
Vitamin C
ASCORBIC ACID--ASCORBATE
Easily absorbed in small lintestine but requires citric acid
prevents oxidation and soaks up free redicals
VC functions
name come from "c" collagen
holds our tissues together
participates in formation of hemoglobin and the development of red blood cells
Vitamin B
act as coenzymes with the cells enzymes
Folic acid
helps form spinal cord and folding over of tissues
Thiamin
needed to affectively absorb carbs
Thiamin Carbs and Metabolism
Carbs increase the need for thiamin
Dificiency of T
beriberi-become deformed and have funny bone/muscle strutures especially in children
Riboflavin
Absobded in upper section of SM IN
small amounts stored in the liver and kidney
active in both energy utilization and tissue building
Niacin comes in two forms
1. Nicotinic acid (NAD)
2. Nicotinamide (NADP)
Vitamin B6 (pyridoxine)
Coenzyme in more than 100 amino acids involving the synethsis of important protiens such as neurotransmitters
Conenzyme in carbs and fat metabolism
Pntothenic Acid
Absorbed in IN and combines with Phosphorus to make the active molecule CoA
Biotin
Sulfur-containing vitamin
Partners with acetyl CoA in reactions that tranfer CO2 from one compound to another
Folate
Coenzyme with the task of attaching single carbons to metabolic compounds
Key molecules formed
--Purines
--Thymine
--Hemoglobin
Folate requirements
Closure of neural tube in early weeks of fetal development
Mom has to be in good Folate status before becoming pregnant otherwise birth defects
Food sources of Folate
Under federal law all grain products including flour bread cerel must by fortified with folic acid
Vitamin B12 (cobalamin)
Complex red molecule with atom at core
occurs as a protein complex in food of animal origin only
Absoroption of VB12
stomach acid needed
bound to glycoprotein called intrinsic factor secreted by mucosal cells lining the stomach
intestinal absorption occurs in the ileum
Functions of VB12
participates in amino acid metabolism and formation of the hume portion of hempglobin
involved in isynthesis of important lipids and proteins that form the mylin sheath
Deficiency in VB12
Pernicious Anema--intrinsic factor which must bind to vitamin B12 for it to be absorbed
Vitamins are needed to stay alive
Complex organic molecules that serve primarily as coenzymes or regulators of body metabolim
Minerals
Not made by living things
Play important roles in Structure and Function
Calcium and Phosphorus give strength to bones and body frame
Iron provides core for heme in hemoglobin
Major Mineral
Calcium
Phosohrus
Magnesium
Sodium
Potassium
Sulfur
Chloride
Sodium is in our _____ in high concentration
Potassium is in our ______ in high concentration
Blood
Cells
Calcium
Serves as a signal inside all cells 2nd messenger
More calcium in blood than any other mineral
Absorption of Calcium happens in the duodenum
Approixmately 1% of body Calcium is in the blood the rest is in the bone
Three agents control calcium balance
1. Parathyroid hormone PTH
2. Vitamin D hormone Calcitriol
3. Calcitonin
Phosphorus
80-90% of P is found in bones and teeth with Calcium
Its present in every living cell but we can run out of P
Sodium
Major cation in the extracellular fluids
MOST IMPORTANT ENZYME ON THE PLANET
Used by Na/K-ATPase to establish and maintain hte elctrochemical gradient across cell membranes
_____ is pumped out of cells by Na/K-ATPase
Sodium
----majority of energy we use goes toward this process
Sodium is pumped out
Potassium is pumped in
Potassium
2x as much in body as Sodium
Na/K-ATPase to establish and maintain the electrochemical concentrtaion gradient in cells
Magnesium
Found in all cells of body
combine with C and P in bones
Activates enzymes for energy production and tissue building
Magnesium is present in all things that live in the soil
Chloride
in Blood=high concentration
in cells= low concentration
Found in extracellular fluid-where it helps control balance
Sodium=_____
Chloride=_____
Sodium= cation
Chloride= antion
Trace elements
1. catalyze chemical reactions
2. serve as structural components of larger molecules
Iron balance is controlled at the site of absorption inthe SM IN becaues there is no system for regualtion of iron excretion once it has entered the body
Iodine
Found in seawater
It is used to make T3 and T4 and not much else
Thyroid gland!!
Thyroid hormones play a key role in regualting BMR
Goiters show up when there is a defincency in Iodine
Zinc
Found in all cells but in very small amounts
Participates in many metabolic activites as a compnent of over 100 different enzymes and a factor in growth
Fluoride
Is injected into water
Helps prevent cavities
Accumulates in the calcified tissues and protects bones and teeth from mineral loss