ANAPHY - Nutrition, Metabolism, and Body Temperature Regulation

Nutrition

- Refers to the science of foods and the substances they contain

- their actions, interaction, and balance in relation to health and disease

- Process by which food is taken into and used by the body

- Includes digestion, absorption, transport, and metabolism

- Study of nutrition + the study of food and drink requirements for normal body function

Nutritional Status

- Refers to the condition of the body resulting from ingestion & utilization of nutrients

Malnutrition

- Refers to either nutrient deficiencies (undernutrition) or nutrient excesses (overnutrition)

Nutrients

- Refer to constituents of food necessary to sustain the normal functions of the body

- chemicals taken into the body that provide energy and building blocks for new molecules

- A balanced diet consists of enough nutrients in the correct proportions to support normal body functions

Nutritional Status Assessment

- Refers to the interpretation of information obtained from anthropometric,

biochemical, clinical, and dietary studies to determine the health status of an

individual as influenced by the intake and utilization of nutrients

- First step in the treatment of malnutrition

Calorie (cal)

- as the amount of energy (heat) necessary to raise the temperature of 1 gram (g)

of water 1’C

Kilocalorie (kcal)

is 1000 cal and is used to express the larger amounts of energy supplied by

foods and released through metabolism

Essential Nutrients

- nutrients that must be ingested because the body cannot manufacture them or it

cannot manufacture them in adequate amounts

- certain amino acids, certain fatty acids, most vitamins, minerals, water, and some

carbohydrates

macronutrient

• nutrients the body needs in larger amounts

• provides the body with energy in the form of calories

• protreins, carbs, lipids, ethanol

micronutrients

• nutrients the body needs in smaller amounts

• do not provide the body with calories

• vitamins, minerals

vitamins

• organic substances

• easily destroyed by cooking with heat or chemical reagents

minerals

• inorganic substances

• not vulnerable to heat, sunlight, or chemical agents

Monosaccharide

- one sugar unit

- building block of all carbohydrates

Disaccharide

- two (2) sugars

- Examples:

- Glucose + fructose = sucrose

- Glucose + galactose = lactose

Oligosaccharides

- 3 to 10 sugar units

Polysaccharide

- more than 10 sugar units

- Examples:

- Starch, grain, vegetables, glycogen

SIMPLE carbohydrates

- No nutritional value

- Cause weight gain

- Recommended amount: sparingly

- Examples:

- Candy and soft drinks

COMPLEX

- Fiber helps decrease colon cancer and heart disease

- Recommended amount: at every meal

- Examples

- Whole grains, pastas, rice, bread

lipids

are heterogeneous group of compounds relatively insoluble in water and freely

soluble in nonpolar organic solvents (ether, chloroform)

- Unlike carbohydrates & proteins, lipids are not chemically related, but are physically

related (in terms of solubility to nonpolar organic solvents)

- They are not true polymers, unlike carbohydrates & proteins

- Functions:

- Important constituent of diet

- Storage form of energy

- Provide thermal insulation

- Serve as electrical insulators of myelinated nerves

- Totally or partially insoluble in water

- Include: triglycerides, steroids, phospholipids, and fat soluble vitamins

Triglycerides

- most common type of lipid in the diet

- accounting for about 95% of the total lipid intake

- If the fat is a liquid form at room temperature, it is referred to as an oil

saturated fats

- if their fatty acids have only single covalent bonds between carbon atoms

- Found in meat, dairy products, eggs, nuts, coconut oil, and palm oil

- Bad for us

- Solid at room temperature

unsaturated fats

- have one or more durable double bonds

- Better for us

- Liquid at room temperature

Monounsaturated fats

- have one double bond

- Include olive and peanut oils

polyunsaturated fats

- have two or more double bonds

- Found in fish, safflower, sunflower, and corn oils

ESSENTIAL FATTY ACIDS

- Fatty acids that are required by humans (since they are not synthesized in the body)

- Rationale:

- Humans lack the enzymes that can introduce double bonds beyond the 9th

carbon

- Essential FA

- Linoleic acid

- A-linolenic acid

- Semi-essential FA

- Arachidonic acid

SHORT CHAIN FATTY ACID

- are produced by bacterial fermentation of dietary carbohydrates

- Also absorbed directly into the blood

- Important source of energy for the colonic mucosa, and metabolism by colonocytes

provides energy for processes such as active transport of sodium

- Food for the colonocytes

MEDIUM-CHAIN FATTY ACID

Absorbed directly into the blood (do not need to be transported to the lymphatic system

via chylomicrons) – because MCFA are relatively water soluble

- Diet rich in MCFA may be of particular benefit in patients with inadequate bile acid

pools

- Do not need carnitine for transport into mitochondria

- Has no effect on atherosclerosis

LONG CHAIN FATTY ACID

- Transported in chylomicrons -> Lymphatic system

TRANS FATTY ACID

- Processed fats and oils

- Raise LDL and lower HDL

- Increase risk for heart disease

CHOLESTEROL

- A steroid

- High concentration in brain, liver, egg yolks, whole milk, cheese, butter, meats

LDL Cholesterol

- Low density lipoprotein

- “Bad cholesterol”

- Carries cholesterol form liver to cells

HDL Cholesterol

- High density lipoprotein

- “good” cholesterol

- Carries cholesterol from cells to liver

- Increase HDL through exercise

proteins

• are chains of amino acids and are found in most of the plant and animal products eaten

• are constructed of 20 different kinds of amino acids

Complete protein food

- contains all nine essential amino acids in the needed proportions, whereas an

incomplete does not

Amino acids

are not stored so a daily supply is required

- Recommended amount:

- 1 to 2 servings dairy group

- 1 to 3 servings nuts/beans

- 0 to 2 servings fish, poultry, eggs

- red meat sparingly

VITAMINS

- Organic molecules in small quantities in food needed for metabolism

- Balanced diet gives body variety of vitamins

- Absence of vitamins results in deficiency diseases

- Fat or water soluble

- Fat soluble vitamins

- include Vitamins A, D, E, and K

- Water soluble vitamins

- include the B-complex and C.

provitamin

- is part of a vitamin that body can assemble or modify into a functional vitamin,

- such as the conversion in the body to active form of Vitamin D.

MINERALS

- are inorganic nutrients that are essential for normal metabolic functions

DAILY VALUES

- Appear on food labels to help people eat healthy

- Based on 2000 kilocalorie diet

- 60% carbs

- 30% total fats

- 10% saturated fats

- 10% proteins

- Used to calculate percent daily value

RDI (REFERENCE DAILY INTAKES)

- Based on the 1968 RDAs for certain vitamins and minerals

DRV (DAILY REFERENCE VALUES)

- Set for total fat, saturated fat, cholesterol, total carbohydrate, dietary fiber, sodium, potassium, and protein.

ESTIMATED AVERAGE REQUIREMENT (EAR)

- Average daily nutrient intake estimated to meet the requirement of 50% of the healthy

individuals in a particular life stage and sex group

- Serves as the foundation for setting the

RDA RECOMMENDED DIETARY ALLOWANCE

- Average daily nutrient intake level that is sufficient to meet the requirements of nearly

all (97-98%) individuals in a particular life stage and sex group

ADEQUATE INTAKE (AI)

- An AI is set instead of an RDA if sufficient scientific evidence is not available to calculate

an EAR or RDA

TOLERABLE UPPER INTAKE LEVEL (TUL, or UL)

- Refers to the highest average daily nutrient intake level that is likely to pose no risk of

adverse health effects to almost all individuals in the general population

- As intake increases above the UL, the potential risk of adverse effects may increase

WATER

- Predominant chemical component of living organisms

- A molecule with electrical charge distributed asymmetrically about its structure

Hydro-PHILIC (water-loving)

- compounds that dissolve easily in water; generally charged or polar

Hydro-PHOBIC (water-fearing)

- nonpolar molecules such as lipids and waxes, which dissolve in chloroform and benzene

METABOLISM

- is the total of all the chemical reactions that occur in the body

CATABOLISM

- energy-releasing process by which large molecules are broken down into smaller ones.

ANABOLISM

- energy-requiring process by which small molecules are joined to form larger ones.

1. ANABOLISM (SYNTHESIS):

- Energy-requiring process

- Example: ADP + P + ATP

2. CATABOLISM (DECOMPOSITION):

- Energy-releasing process

- Example: ATP = ADP + P

ANAEROBIC RESPIRATION

- is the breakdown of glucose in the absence of oxygen (O2)

- In human cells, this results in the production of

- two (2) molecules of lactate

- two (2) molecules of ATP

GLYCOLYSIS

- is a series of chemical reactions that occurs in the cytoplasm

- Results in the breakdown of glucose to two pyruvic acid cycles

- undergoes several reactions to produce:

- two (2) pyruvic acid molecules

- two (2) ATP

- two (2) NADH

LACTATE FORMATION

- Pyruvic acid is converted to lactic acid and converted to lactate

- the ionized form of lactic acid.

AEROBIC RESPIRATION

- the breakdown of glucose in the presence of oxygen (O2)

- In human cells, this results in the production of

- Carbon dioxide,

- Water

- 36 molecules of ATP.

ADENOSINE TRIPHOSPHATE (ATP)

- Energy carrier

- Energy is released when ATP is broken down

- Some ATP is produced in the cytoplasm

- Most ATP is produced in the mitochondria

CARBOHYDRATE METABOLISM

- Monosaccharides are the breakdown products of carbohydrate digestion, with the most

important being glucose.

- Any excess glucose in the blood following a meal can be used to form glycogen, or it can

be partially broken down and the components used to form lipids.

- The metabolism of carbohydrates involves:

- Anaerobic respiration

- Aerobic respiration

- Glycolysis being anaerobic

- Citric Acid Cycle being aerobic

Acetyl-CoA Formation

- Each pyruvate acid moves from the cytoplasm into the mitochondrion, where they are

converted into acetyl-CoA.

CITRIC ACID CYCLE (Krebs Cycle)

- Each acetyl-CoA molecule enters the citric acid cycle where NADH, FADH2, and ATP is

formed

ELECTRON TRANSPORT CHAIN

- A series of electron-transport molecules attached to the inner mitochondrial membrane

Triglycerides

- are body’s main energy storage molecules

KETONES

- Acetyl-CoA combines to form what?

PROTEIN METABOLISM

Proteins are digested into amino acids

- Amino acids function:

- Taken up by the liver

- Used to make needed proteins

- Can be converted into pyruvic acid and acetyl-CoA

- Metabolism results in ammonia which is converted to urea (liver)

METABOLIC RATE

- Total amount of energy produced and use in body per unit of time

BASAL METABOLIC RATE

- energy needed to keep resting body functional

- Used to determine number of kilocalories need per day

Heat (q)

- Energy transfer between two bodies at different temperatures

Work (w)

- Energy transfer between a system and its surroundings in the form of compression or

expansion of gas Internal

Energy (U)

Total energy attributed to particles of matter & their interactions within a system, composed of thermal energy & chemical energy

Enthalpy (H)

- Energy of a reaction

Entropy (S)

- Degree of disorderliness

- Measure of the change in randomness or disorder of the reactants and products

Heat Capacity (c)

- Amount of heat required to raise temperature of an object/substance by 1 degree

Specific heat Amount of heat required to raise temperature of an object per gram

Thermodynamics

- study of the interconversion of heat and other kinds of energy

● ZEROTH LAW OF THERMODYNAMICS

- States that if two bodies are each in thermal equilibrium with a third body, they are also in equilibrium with each other

● 1ST LAW OF THERMODYNAMICS

- Energy can be converted from one form to another, but cannot be created nor destroyed

● 2ND LAW OF THERMODYNAMICS

- The entropy of the universe increases in a spontaneous process, and remains

unchanged in an equilibrium process

- In simpler terms:

- Entropy of the universe = Entropy of the reaction + Entropy of the

surroundings

● 3RD LAW OF THERMODYNAMICS

- The entropy of a system approaches a constant value when absolute temperature

reaches absolute zero

BODY TEMPERATURE REGULATION

- The average normal temperature is usually considered to be 37°C (98.6°F) when measured orally and 37.6°C (99.7°F) when measured rectally.

Body temperature

- is maintained by balancing heat input with heat loss.

- Amount of heat exchanged between the environment and body is determined by

difference in temperatures.

Temperature regulation

- occurs by DILATION and CONSTRICTION of blood vessel in the skin

- Sweat glands and skeletal muscles are also involved

HOMEOSTASIS

- occurs by a negative feedback system.

HYPOTHALAMUS

- is the control center of monitoring body temperature

conduction

heat transfer between objects via direct contact

- Exchange of heat between objects that is in direct contact.

- Example: contact of the bottom of the feet and the ground

convection

heat transfer by movement of fluid

- Transfer of heat between body and air or water.

- Example: cool breeze over Body

radiation

heat transfer by which heat is transmitted without any medium

- Gain or loss of heat as infrared energy between 2 objects not in physical contact.

- Examples: sun, hot sand, Snow

Humidity

- May affect thermoregulation by limiting sweat evaporation and thus heat loss

- Low-intensity shivering

- Primarily uses fats

• For long-term use

- High-intensity shivering

- Primarily uses glucose

- For short-term use

- Non-shivering thermogenesis

- is a minor mechanism of heat generation mostly seen in babies of lower

mammals

- Produced by brown adipocytes

EVAPORATION

- Conversion of water from liquid to gas.

- Example: water from body surface