ZOO 251 Exam 3 Florence Wen SELU

nutrition

-source of fuel for body

-provide energy for all biological work

-serve as raw materials to replace worn-out bio-molecules and cells

energy balance, hereditary factors, environmental factors

what things determine weight

gain weight

what happens to your weight when you intake more energy than you output

lose weight

what happens to your weight when you intake less calories than you output

ghrelin

Short-Term Appetite Regulators:

-secreted by parietal cells when stomach is empty

-stimulate sensation of hunger in the hypothalamus

peptide YY (PYY)

Short-Term Appetite Regulators:

-secreted by enteroendocrine cells of intestine as food enters stomach

-signal fullness and terminate eating

Choleocystokinin (CCK)

Short-Term Appetite Regulators:

-secreted by enteroendocrine cells of intestine

-appetite suppression effect

-stimulate fat and protein digestion

leptin

Long-Term Appetite Regulators:

-secreted by adipocytes

-level is proportional to fat stores

-in animals, high amounts of this suppress appetite (not always the case in humans)

insulin

Long-Term Appetite Regulators:

-secreted by pancreatic beta cells

-lowers blood sugar content

-stimulate amino acids and glucose intake and puts it into storage

-stimulates production of glycogen and fats

calorie

Amount of energy needed to raise 1 gram of water 1 degree C

kcal

1000 calories (this is usually what we refer to when referring to foods)

carbs, proteins, fats

where do our dietary calories come from

empty calories

-suppress appetite, fail to provide other nutrients that body requires

-usually alcohol and sugary foods

-promote malnutrition

essential nutrients

-things that our body must consume

-we cannot make these

-ingested, absorbed into tissue for growth, repair, maintenance of body

-6 major macronutrients

water, carbs, lipids, and proteins

what are the four macronutrients our body needs

vitamins and minerals

what are the two micronutrients our body needs

carbs

Macronutrients:

-4060% of daily calories should be from these (125-175 g)

-these are broken down within a few hours of absorption through glycolysis

Glycolysis

breaking down of 1 glucose molecule into 2 pyruvate molecules

pyruvate molecules

what does glycolysis break carbs down into

anaerobic fermentation or aerobic respiration

what two ways can pyruvate be broken down further after glycolysis

anaerobic fermentation

-pyruvate converted into lactic acid without using O2

-this happens when the demand for ATP exceeds O2 supply

-heavy exercise increase demand fro O2 and ATP to muscles

-muscle generates small amount of energy and lactic acid

2ATP

what is the end product of anaerobic fermentation

aerobic respiration

-most ATP generated in mitochondria

-requires O2 as final electron acceptor

-pyruvate molecules get converted into acetyl CoA, enter's krebs cycle (NADH and FADH2), then electron transport chain

-body uses all of the carbs it needs for energy at the time and then stores the rest

-ATP cannot be stored

38ATP

what is the end product of aerobic respiration

glycogenesis

creation of glycogen (excess glucose can be converted to glycogen through this)

-stimulated by insulin

insulin

what is glycogenesis stimulated by

400-450 g

how much glycogen can be stored in the skeletal muscle, cardiac muscle, and liver

glucagon

A protein hormone secreted by pancreatic endocrine cells that raises blood glucose levels (does the opposite of insulin)

fat

when reserves are full and energy is not needed a the time of consumption excess glucose is converted to what

intermediates

what do carbs provide us with to completely breakdown fat (we need carbs to help properly burn fat from body)

lipids

-less than 30% of daily calorie count

-for most Americans, this intake is around 50%

15% (men), 25% (women)

what are healthy body fat percentages for men and women

fats

-account for most of body's stored energy

-phospholipid, cholesterol, and other lipids play vital structural and physiological roles in body (ie phospholipid bilayer in cell membranes)

cholesterol

what lipid does the body need to make steroid hormones

linoleic and linolenic acid

what two acids are essential fatty acids to the body

80-90%

what percent of resting energy needs come from fats

carbs

hydrophilic, absorb water, expand and occupy more space tissue when stored

fats

hydrophobic, contains almost no water, more compact energy storage

fat

what is more superior when talking about energy storage

-less oxidize than carbs

-contains 2x as much energy as carbs

-has 9 kcal/g vs carbs (4 kcal/g)

119 hours

how long can a man run without break by using energy reserves from fat

1.6 hours

how long can a man run without break by using energy reserves from carbs

lipogenesis

synthesis of fats from other molecules

-glucose enters kreb's cycle and is diverted to fatty acids

-glycerol and fatty acid condensed to make a triglyceride, which is stored in adipose tissue

lipids

-hydrophobic

-cannot dissolve in water or blood

-complex of fats and proteins form to transport lipid through blood plasma

lipoproteins

soluble proteins combine with and transport fat or other lipids in blood plasma

-has cholesterol and triglycerides in the middle, converted by a proteins coating: higher ratio of protein to lipid, the higher the density

chlyomicrons

Lipoproteins:

-carry triglycerides from small intestine to lymphatic system

-ultimately to blood stream, where triglycerides are broken down and stored in adipocytes

very low density lipoproteins (VLDL)

Lipoproteins:

-produced in liver and carry triglcyerides to adipocytes

low density lipoproteins (LDL)

Lipoproteins:

-after VLDL lose triglycerides, becomes LDL and carries cholesterol to cells where it is used for cell membranes

-"bad cholesterol"

high density lipoproteins (HDL)

Lipoproteins:

-empty shell secreted from liver, picks cholesterol and triglycerides from tissue and brings it back to liver

-want more of these in body

200-239 mg/ dL (deciliter)

borderline plasma cholesterol levels

over 240 mg/ dL (deciliter)

extremely high plasma cholesterol levels

lipolysis

breakdown of lipids for energy when we don't have carbs available

glycerol

end product of lipolysis (half as much as glucose)

44-60 g

humans should be eating how many grams of protein daily

your weight in pounds X 0.37 = g of protein

how do you calculate the amount of protein you need in grams

amino acids

what are essential to proteins

Isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine

what are the 8 essential amino acids (don't NEED to know this, but it could be bonus)

positive nitrogen balance

ingest more nitrogen than excreted

-important in children, resistance training athletes, and pregnant women

negative nitrogen balance

excrete more nitrogen than ingested

-muscle atrophy, caused by insufficient carb and fat intake

lipids and proteins

what will our body rely on if carbs are not consumed (can become problematic)

-excess ketones are produced

ketosis

elevated ketones in blood

ketoacidosis

pH imbalance in blood due to elevated ketones

minerals

inorganic compounds in body that your body needs (K, Na, Ca, etc)

vitamins

organic molecules in body that your body needs

A, D, E, K

what are the fat-soluble vitamins

C and B

what are the water-soluble vitamins

obesity

Clinical Application:

-clinically defined as weight more than 20% above recommended norm

-in US, 30% of population, 35% overweight

-often hereditary

obesity

Clinical Application:

-worsened by overfeeding in infancy and childhood

-shorten life expectancy, increases risk of atherosclerosis, hypertension, diabetes mellitus, joint pain, kidney stones, gallstones

-can cause colon, rectum, prostate, breast, uterus, and liver cancers

obesity

Clinical Application:

-Leptin resistance may be a cause of this

-high leptin should signal brain to decrease eating, but brain doesn't receive leptin signal and thinks body is starving

alcohol

-use of popular mind altering drug

-source of empty calories

-addictive drug

-toxic drug to body

-absorbed rapidly by digestive tract

-both water and fat soluble

-easily distributed to tissues throughout body

-detoxified by enzyme called alcohol dehydrogenase

alcohol dehydrogenase

what is the enzyme that detoxifies alcohol (males have more of this enzyme than females)

alcoholism

Clinical Application:

-tolerance of high concentrations of alcohol

-impaired physiological, psychological, social functionality

-withdrawal symptoms occurring when intake is reduced or stopped

-can cause delirium tremens (DT)

delirium tremens

restlessness, insomnia, confusion, irritability, tremors, incoherent speech, hallucinations, convulsions, coma

-has a 5-15% mortality rate

-onsets from alcoholism

urinary system

-primary system in pH, fluid and electrolyte regulation

-waste excretion

-eliminate liquid metabolic waste, excess water, water soluble vitamins, and minerals

-aids in blood pressure regulation

-promotes RBC production

blood volume and pressure

Urinary System:

-what is regulated by the urinary system by conserving or eliminating water

renin

hormone secreted by the kidney; it raises blood pressure by influencing vasoconstriction (narrowing of blood vessels)

angiotensin II

increases blood pressure by stimulating kidneys to reabsorb more water and by releasing aldosterone

lung

Urinary System:

-what organs does the urinary system work with to control body pH by managing CO2 content

respiratory, integumentary, digestive, urinary

what four systems separate wastes from body fluids and eliminate them from the body

respiratory system

Excretion:

-this system excretes CO2, small amounts of other gases, and water

integumentary

Excretion:

-this system excretes water, inorganic salts, lactate, and urea in sweat

digestive

Excretion:

-this system eliminates food residue (not a process fo excretion)

-actively excretes water, salts, CO2, lipids, bile pigments, cholesterol, and other metabolic wastes

urinary

Excretion:

-this system excretes a broad variety of metabolic wastes, toxins, drugs, hormones, salts, hydrogen ions, and water

nitrogenous waste

-produced when proteins and amino acids are metabolized

-yields ammonia (highly toxic)

-ammonia is transported to liver

-converts ammonia to urea (less toxic)

blood urea nitrogen

-level of nitrogenous waste in blood

blood urea nitrogen (BUN)

Clinical Application:

-normal range is 10-20 mg/ dL

-once elevated above this range it may indicate renal insufficiency (kidney failure)

-can progress to uremia

-convulsions, coma, and death can follow within a few days

azotemia

elevated BUN

uremia

syndrome of diarrhea, vomiting, dyspnea, and cardiac arrhythmia stemming from the toxicity of nitrogenous waste

kidneys, ureter, urinary bladder, urethra

parts of urinary system

nephron

what is the functional unit of the kidneys

kidneys

-bean shaped

-contains about 1 million nephrons

-weighs 150g

-10 cm long, 5 cm wide, 2.5 cm thick

-protected by 3 layers of connective tissue (renal fascia, perirenal fat capsule, fibrous capsule)

renal fascia

3 Layers of Connective Tissue in Kidneys:

-binds kidney abdominal wall

perirenal fat capsule

3 Layers of Connective Tissue in Kidneys:

-layer of adipose tissue, cushions kidney and holds it in place

fibrous capsule

3 Layers of Connective Tissue in Kidneys:

-encloses kidney like cellophane wrapper anchored at hilum (slit where ureter exits kidney)

-protects kidney from trauma and infection

kidneys

-4% of body weight

-receives about 1.2 L of blood per minute

-20% of cardiac output (renal fraction)

-for waste removal

-demonstrates importance of kidneys in regulating blood volume and composition

renal circulation

the movement of blood from the body organs through the kidneys

renal artery

blood vessel that carries blood to the kidney from aorta

segmental arteries

what does the renal artery divide into

interlobar arteries

segmental arteries further divide into what

renal column

what does the interlobar artery peentrate

cortical radiate artery

Renal Circulation:

-ascends through cortex