Nutrition

What are the three short term regulations of apetite

Neural signals from GI tract, Blood nutrient levels, GI tract hormones

Short term regulation of appetite - Neural signals from GI tract

As you stomach and intestine fills (gastrointestinal) → vagus nerves sends signals to suppress hunger center

Short term regulation of appetite - blood levels of nutrients
what is the exception

After you eat, nutrients fill up your blood stream → suppresses your hunger/eating

However, when you ingest sugar, it activates the brain’s reward/pleasure center which releases dopamine → makes eating feel rewarding → overeating

Short term regulation of appetite - Hormonal

Hormones in the GI tracts are released to suppress hunger and tell you that you’re full

Ghrelin, PYY, CCK, Amylin, Leptin, Insulin\

what does each one do and which ones are short term regulation/long term regulation

Short term

• Ghrelin → stimulates neuropeptide Y (NPY) secreting neurons in the hypothalamus → increases hunger

• PYY (Large intestine)→ inhibits NPY secreting neurons → satiated + reduces hunger

• CCK (small intestine) → inhibits NPY secreting neurons → satiated + reduces hunger

• Amylin (pancreatic beta cells) → satiated + reduces hunger

• Insulin (pancreatic beta cells) → inhibit NPY secreting neurons → satiated + reduces hunger

Long term

• Leptin (adipose/ fat tissues) → inhibits NPY secreting neurons (satiated and reduce hunger) + stimulate melanocortin neurons (decrease appetite)

arcuate nucleus and what 2 things does it have

region on the hypothalamus

has neuropeptide Y secreting neurons (NPY neurons) → increase hunger

and melanocortin secreting neurons → satiated / reduce hunger

What is the long term regulation of appetite

LeptinL

Leptin - what is it and what does it do and what is the main function

Hormone secreted by fat cells

Increase fat cells = increased leptin → lowers appetite

Decreased fat cells (body fat) = decreased leptin → increases hunger
Main function is to protect against weight loss when body is nutritionally deprived.

What other factors also affect appetite (4)

Temperature → cold → hungry

Stress → different depending on person (ex: comfort food → serotonin → calming effect → overeating)

Psychological factors

Sleep deprivation can increase hunger

BMI - what does it stand for, what is the equation, and what is considered overweight and obese

Body mass index = weight (lbs) * 705/ (height in inches)²

Overweight = 25-30

Obese = >30

Nutrients and what are the 2 major groups

Any ingested chemical used for growth, repair, and maintenance of the body

macronutrients / major nutrients

micronutrients

Macronutrients and what are the 4

Major nutrients that the body needs in large amounts

Carbohydrates, lipids, protein, and water

Micronutrients and what are the 2

Nutrients the body needs in small amounts

Vitamins and minerals

Essential nutrients

nutrients that the body cannot make itself in sufficient amounts → must come from food/ diet

Carbohydrates the bodys’ what + what are they broken down to

Main source of energy production

broken down to glucose eventually

What are the two main functions of sugar (carbohydrates)

• structural component of other molecules (nucleic acids, glycoprotein, glycolipids, ATP, GTP, cAMP

• use for fuel

  • easily oxidized → broken down and releases energy which is used to make ATP chemical energy

Most cells meet energy needs through

a combination of carbohydrates and fats

What are the dietary source of carbohydrates

Plants

What are simple sugars and where do they come from (3)

monosaccharides and disaccharides (carbohydrates)

fructose, sucrose, maltose, lactose

→ fruits, milk, honey

What are complex carbs and where do they come from

polysaccharides → starch, fibers (pectin and cellulose) → vegetables and grains

How does fat compare to carbohydrate as a energy storage (2)

1. it is hydrophobic and compact to store more energy

2. Less oxidized so it contains much more energy

Lipid function - absorption

lipids help the body absorb fat soluble vitamin

Lipid function - fuel + what effect does it have

triglyceride can be broken down into fuel for hepatocytes (liver cells) + skeletal muscle

glucose sparing + protein sparing effect → if enough fat is available it will be used instead of protein and carbs

Lipid function → structural (2)

Important part of plasma membrane and myeline sheaths

fatty deposits - what is it and what 3 functions

adipose tissues → Protection, insulation, concentrated source of energy

Lipid fucntion - what are fatty acids and cholesterol precursors to

Fatty acid → prostaglandins

Cholesterol → steroids, bile salt, vitamin D

Saturated vs unsaturated (cis vs trans) fats

Saturated → no double bonds → usually solid at room temp

unsaturated → 1 or more double bond → usually liquid at room temp

• Cis → same side vs trans → opposite side

Essential fatty acids are ______ fat and the two are

unsaturated fat → Omega 3 and 6

Dietary source of saturated and unsaturated fats (which are triglycerides)

Saturated → meat and dairy

unsaturated → seeds and oil

Functions of cholesterol → precursor to what 3, major component of what, what are the two sources of blood cholesterol, how does it leave the body(2), is it used as a energy source

1. precurosor to bile salt, vitamin D, and steroid hormones

2. major component of plasma membrane

3. 15% of blood cholesterol comes from food, 85% produced by liver

4. it leaves when it is catabolized/broken down and excreted in bile salts

   1. IT IS NOT USED AS A ENERGY SOURCE

Lipoproteins

Since cholesterol and triglycerides don’t dissolve well in water (hydrophobic)

so lipoproteins helps transport them in the blood which is mainly water

What are the three types of lipoproteins and what is the relationship between lipids and density

VLDLs - very low density lipoproteins

LDLs - low density lipoproteins

HDLs - high density lipoproteins

higher percentage of lipids → lower density

VLDLs

very low density lipoproteins (lots of lipids) → carry triglycerides from liver to peripheral tissues (mainly adipose)

after it removes triglycerides → it becomes LDLs because it has mostly cholesterol remaining

LDLs (also called what)

bad cholesterol

Lots of lipids (cholesterol → low density)

transport cholesterol from liver/blood to peripheral tissues

HDLs (also called what) - 2 funcitons

good cholesterol

Less lipids and more proteins → higher density

1. Bring excess cholesterol from peripheral tissue back to liver to be broken down and secreted into bile

2. bring cholesterol to steroid producing organs

Chylomicron

another type of lipoprotein that carries dietary fat from small intestine to rest of body

(small intestine → lymph → blood stream → lipoprotein lipase remove lipid from chylomicron → cells / liver(dispose)

The ratio of _____ to _____ affects blood ______ levels

• Saturated fatty acids

• Unsaturated fatty acids

• Trans fat

• Saturated fatty acid → stimulate liver production of cholesterol and inhibit cholesterol excretion (more saturated → increase blood cholesterol)

• Unsaturated fatty acid → increase cholesterol excretion + cholesterol catabolism/ breakdown into bile salt (more Unsaturated → decrease blood cholesterol level)

• Transfat → Increase LDL (bad cholesterol) and decrease HDL (good cholesterol) → bascially more cholesterol stored in body tissues while less is being brought to liver to break down

Trans fat

partially hydrogenated vegetable oil (healthy oil forced to turn into solids) → unsaturated fat that acts like saturated fat → ex: margarine

Protein funcitons

• Structural

• functional molecules

• Nitrogen balance

• Hormonal control

Structural → keratin, collagin, elastin, muscle proteins

functional molecules → enzymes and hormones

Nitrogen balance → proteins contain nitrogen

Hormonal control → anabolic proteins like growth hormones and sex hormones can accelerate protein synthesis

Proteins

● Dietary Sources:

• Animal products like eggs, milk, fish, and most meats

contain _________

• Legumes (beans/peas) and cereals together contain ___________

Animal products contain complete proteins

legumes (beans/peas) and cereal contain all essential amino acids

Body can only produce ______ amino acids, the other ______ are the
_______, which _______

Body can only produce 12/20 amino acids, the other 8 are essential amino acids, which can only be obtained through the diet.

Vitamins and what are the two types

vitamins are organic compounds that participate in metabolic reactions by acting as coenzyme

water soluble and fat soluble vitamins

Water soluble vitamins (2)

Vitamin Bs and Cs

absorbed with water

Not stored in body → need to be ingested daily

Fat soluble vitamins (4)

Vitamins A, D, E, K absorbed with lipid digestion products (when triglyceride is broken down into fatty acids and monoglycerides → these vitamins are absorbed together with these things)

stored in the body except for vitamin K

Minerals → what are the main 7 and what about the rest

inorganic nutrients required in moderate amounts

• calcium, phosphorous, potassium, sulfur, sodium, chloride, magnesium

Rest are needed in trace amounts

Metabolism and what are the two types

biochemical reactions inside cells involving nutrients

• Anabolism and catabolism

Anabolism vs catabolism

Anabolism → synthesis of large molecules from smaller ones

Catabolism → hydrolysis of complex structures → breaking down into smaller ones

Cellular respiration

catabolism of food fuels/ molecules, which releases energy to be used to create ATP (the body’s energy currency) which is continually recycled

What are the three stages of metabolism

Digestion and absorption

Cellular processing

Oxidative

Metabolism - digestion and absorption - where and what

food is broken down and absorbed in the GI tract as nutrients, which is transported to tissue cells by the blood stream

metabolism - Cellular processing - where and what

in the cytoplasm

• nutrients undergo either anabolism into lipids, proteins, glycogens or catabolism (glycolysis) into intermediates

metabolism - oxidative - where and what

in the mitochondria → breakdown of intermediates into CO2, water, and ATP

Oxidation vs reduction

oxidation - gain of oxygen → loss of electron/ hydrogen ion (OIL RIG)

reduction - loss of oxygen → gain electron/ hydrogen ion

Redox reactions
Oxidized substances

Reduced substances

transfer of electrons from one molecule to another

oxidized substances lose electrons and energy

reduced substances gain electron and energy

FAD and NAD+

coenzymes that act as electron acceptors (or hydrogen acceptors) → get reduced → NADH and FADH bringing electron to later parts of metabolism

What are the two types of ATP synthesis

Substrate level phosphorylation and oxidative phosphroylation

Substrate level phosphorylation

fast and low output of ATP → glycolysis and kreb (citric acid) cycle

Oxidative phosphroylation

• carried out by ______

• nutrient energy is used to generate ________ across _______

• H+ flows through ______, which _________

Slow but high output of ATP

• 
  

electron transport proteins , H+ gradient across mitochondrial membrane, ATP synthase, generates energy and turns ADP → ATP