Ch. 25 Nutrition

what is nutrition

chemicals used by body to produce energy, provide building blocks or function in other chemical reactions

what is required in large amounts

carbs, proteins, lipids, water

what is required in small amounts

vitamins and minerals

what are essential nutrients

must be supplied in the diet or ingested

cannot be synthesized/made by body

examples of essential nutrients

certain amino acids, fatty acids, most vitamins, minerals, water and a mininum number of carbs

what are kilocalories

measure of energy supplied by food and released through metabolism

what does a food guide pyramid suggest

that your diet should contain a variety of foods

where do carbohydrates come from

plants

except lactose-milk

what are monosaccharides

glucose, fructose, galactose

what are disaccharides

sucrose, lactose, maltose

what are polysaccharides (complex)

starch, glycogen, cellulose(indigestible)

what are disaccharides and polysaccharides converted to

glucose

used for energy or stored as glycogen or fat

what does the liver convert monosaccharides into

glucose which is used as an energy source to produce atp

what is excess glucose converted to

glycogen

stored in muscles and liver cells

what happens to excess carbs beyond storage

converted to fat

what happens if your daily diet is deficient in carbs

decrease of muscle mass

what are lipids

the body's main energy storage molecules

what are triglycerides

95%

used for energy to produce ATP or stored in adipose tissue, liver

what are saturated fats

meat fats, whole milk, cheese, eggs

what are unsaturated fats

olive and peanut oil

what is cholesterol

steroid found in liver, egg yolks but not found in plants

what are phospholipids

major components of plasma membranes

what are linoleic acids

essential fatty acids

found in seeds, nuts , legumes, grains and green leaves

what are proteins

chains of amino acids

what are essential proteins

must be obtained in diet (9)

what are nonessential proteins

body can synthesize (11)

what are complete proteins

a food that contains all 9 essential amino acids

meat, fish, poultry, milk, cheese, eggs

what are the functions of proteins

Protection (antibodies),

regulation (enzymes, hormones), structure (collagen),

muscle contraction (actin, myosin), transportation (hemoglobin, ion channels)

how do proteins regulate the acid base balance of the blood

by acting as buffers

recommended amount of carbohydrates

60% of daily intake of kilocalories

recommended amount of lipids

30% or less of total daily kilocalories

Recommended amount of protein

10% of total kilocalories per day

what are vitamins

small dietary organic compounds that are necessary for metabolism

but are a class of nutrients we require the least amount

what do vitamins function as

conenzymes or parts of coenzymes (combine w enzymes make functional)

how do vitamins work as organic molecules

exist in minute quantities in food

what are provitamins

substance that can be assembled by the body into a functioning vitamin

what are lipid soluble vitamins

A, D, E, K; can be stored in fatty tissues to the point of toxicity.

what does too much vit a cause

bone and muscle pain

skin disorders

hair loss

increased liver size

what does too much vit d cause

deposition of ca in kidneys, heart, blood vessels

what are water soluble vitamins

b, c, and all others

remain short time then excreted

what does too much vit c cause

stomach inflammation/diarrhea

what are antioxidants

prevent formation of free radicals

what are free radicals

chemicals produced by metabolism that are missing electrons

take electrons from chemicals in cells, damaging them

why are fat soluble vitamins toxic in large doses

they can be stored and accumulate in body tissues

what happens if a vitamin's chemical structure is destroyed by catabolism

it would become nonfunctional

vitamin d

bone growth

vitamin a

rhodopsin synthesis

folate

nucleic acid synthesis, hemopoiesis, prevention of birth defects

vitamin e and c

antioxidants

vitamin c

collagen synthesis(water soluble)

vitamin b12

red blood cell production

vitamin k

blood clotting

what are inorganic minerals

necessary for normal metabolic functions

what are the functions of minerals

establish resting membrane potentials, generate action potentials,

add strength to bones and teeth, buffers,

involved in osmotic balance; are components of coenzymes, vitamins, hemoglobin.

how are minerals obtained

from animal and plant sources

mins. attached to plant fibers are difficult to absorb

calcium

bone formation

mineral

iron

part of the hemoglobin molecule

mineral

zinc

co2 transport and metabolism

mineral

chlorine

acid-base balance

mineral

potassium

muscle and nerve function

mineral

cobalt

erythrocyte production

mineral

selenium

component of many enzymes

mineral

what is metabolism

total sum of all chemical changes that occur in body

What is catabolism

energy releasing process where large molecules broken down to smaller

the digestion of complex carbs - ex.

what is anabolism

energy requiring process where small molecules joined to form larger molecules

ex. the production of protein by cells

what is atp

the energy currency of the cell

what is used to produce atp

Energy in carbohydrates, lipids, and proteins

through oxidation-reduction reactions

where does glycolysis take place

in the cytoplasm of the cell

results in atp

what is the mitochondrion

the site of the citric acid cycle and the electron-transport chain

what is the electron transport chain

where electrons pass from one electron carrier to another

what is aerobic respiration

breakdown or oxidation of one molecule of glucose in presence of oxygen to produce carbdio, water, 38atp molecules(36mol. net)

most atp molecules that sustain life are produced how

aerobic respiration

what is a hydrogen atom

a major player in the production of energy from nutrient molecules

what happen when glucose is metabolized in the absence of oxygen

one of the end products is lactic acid

what is one difference between anaerobic and aerobic respiration

aerobic produces more ATP than anaerobic

glucose, amino acids, and fatty acids can be metabolized with the cell to liberate what

energy

what happens to adipose tryglycerides

broken down and released as free fatty acids

what happens to free fatty acids

taken up by cells and broken down by betaoxidation into acetylcoa

what does acetylcoa do

enter citric acid cycle

be converted to ketone bodies(ketogenesis) in liver

ketones travel to skel.mus and are used in citric acid cycle to produce atp

what is the cori cycle

a series of metabolic reactions in the liver that converts lactic acid into glucose

what does the presence of keton bodies in urine indicate

increased metabolism of fatty acids

what happens with uncontrolled diabetes mellitus

increased lipid metabolism will cause an increase in keton bodies formation

What is glycogenesis?

excess glucose used to form glycogen

what is lipogenesis

when glycogen stores filled, glucose and amino acids used to synthesize lipids

What is glycogenolysis?

breakdown of glycogen to glucose

What is gluconeogenesis?

formation of glucose from amino acids and glycerol

what can non-essential amino acids be formed by

transamination

involves removing an amine group from an amino acid and transfer to keto acid

can also be eaten

what are amino acids used for

to synthesize proteins

what happens if amino acids are used for energy

undergo oxidative deamination

what is produced as by products of oxidative deamination

ammonia and keto acids

what is ammonia converted to

urea

excreted

where are amino acids not stored

in the body

what is the absorptive state

period immediately after eating when nutrients absorbed through intestinal wall into circulatory and lymphatic systems

about 4 hours after each meal

what is the postabsorptive state

occurs late in morning, afternoon, night after absorptive state concluded

blood glucose lev. maintained by conversion of other molecules to glucose

what is metabolic rate

total amount of energy produced and used by body per unit of time

estimated by amount of oxygen per minutes

what is basal metabolic rate

energy used at rest

60%of metabolic rate

component of metabolic rate

what is thermic effect of food

energy cost to digest, absorb, and assimilate food

10%

component of metabolic rate

what is muscular activity

energy used for muscle contraction

30%

component of metabolic rate

how is total energy expenditure estimated

from bmr, thermic effect of food, and physical activity

what is free energy

total amount of energy liberated by the complete catabolism of food

43% used to produce atp

57% lost as heat